src/Tools/isac/IsacKnowledge/Rational.ML
branchisac-update-Isa09-2
changeset 37947 22235e4dbe5f
parent 37946 a28b5fc129b7
child 37948 ed85f172569c
     1.1 --- a/src/Tools/isac/IsacKnowledge/Rational.ML	Wed Aug 25 15:15:01 2010 +0200
     1.2 +++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.3 @@ -1,3786 +0,0 @@
     1.4 -(*.calculate in rationals: gcd, lcm, etc.
     1.5 -   (c) Stefan Karnel 2002
     1.6 -   Institute for Mathematics D and Institute for Software Technology, 
     1.7 -   TU-Graz SS 2002 
     1.8 -   Use is subject to license terms.
     1.9 -
    1.10 -use"IsacKnowledge/Rational.ML";
    1.11 -use"Rational.ML";
    1.12 -
    1.13 -remove_thy"Rational";
    1.14 -use_thy"IsacKnowledge/Isac";
    1.15 -****************************************************************.*)
    1.16 -
    1.17 -(*.*****************************************************************
    1.18 -  Remark on notions in the documentation below:
    1.19 -    referring to the remark on 'polynomials' in Poly.sml we use
    1.20 -    [2] 'polynomial' normalform (Polynom)
    1.21 -    [3] 'expanded_term' normalform (Ausmultiplizierter Term),
    1.22 -    where normalform [2] is a special case of [3], i.e. [3] implies [2].
    1.23 -    Instead of 
    1.24 -      'fraction with numerator and nominator both in normalform [2]'
    1.25 -      'fraction with numerator and nominator both in normalform [3]' 
    1.26 -    we say: 
    1.27 -      'fraction in normalform [2]'
    1.28 -      'fraction in normalform [3]' 
    1.29 -    or
    1.30 -      'fraction [2]'
    1.31 -      'fraction [3]'.
    1.32 -    a 'simple fraction' is a term with '/' as outmost operator and
    1.33 -    numerator and nominator in normalform [2] or [3].
    1.34 -****************************************************************.*)
    1.35 -
    1.36 -signature RATIONALI =
    1.37 -sig
    1.38 -  type mv_monom
    1.39 -  type mv_poly 
    1.40 -  val add_fraction_ : theory -> term -> (term * term list) option      
    1.41 -  val add_fraction_p_ : theory -> term -> (term * term list) option       
    1.42 -  val calculate_Rational : rls
    1.43 -  val calc_rat_erls:rls
    1.44 -  val cancel : rls
    1.45 -  val cancel_ : theory -> term -> (term * term list) option    
    1.46 -  val cancel_p : rls   
    1.47 -  val cancel_p_ : theory -> term -> (term * term list) option
    1.48 -  val common_nominator : rls              
    1.49 -  val common_nominator_ : theory -> term -> (term * term list) option
    1.50 -  val common_nominator_p : rls              
    1.51 -  val common_nominator_p_ : theory -> term -> (term * term list) option
    1.52 -  val eval_is_expanded : string -> 'a -> term -> theory -> 
    1.53 -			 (string * term) option                    
    1.54 -  val expanded2polynomial : term -> term option
    1.55 -  val factout_ : theory -> term -> (term * term list) option
    1.56 -  val factout_p_ : theory -> term -> (term * term list) option
    1.57 -  val is_expanded : term -> bool
    1.58 -  val is_polynomial : term -> bool
    1.59 -
    1.60 -  val mv_gcd : (int * int list) list -> mv_poly -> mv_poly
    1.61 -  val mv_lcm : mv_poly -> mv_poly -> mv_poly
    1.62 -
    1.63 -  val norm_expanded_rat_ : theory -> term -> (term * term list) option
    1.64 -(*WN0602.2.6.pull into struct !!!
    1.65 -  val norm_Rational : rls(*.normalizes an arbitrary rational term without
    1.66 -                           roots into a simple and canceled fraction
    1.67 -                           with normalform [2].*)
    1.68 -*)
    1.69 -(*val norm_rational_p : 19.10.02 missing FIXXXXXXXXXXXXME
    1.70 -      rls               (*.normalizes an rational term [2] without
    1.71 -                           roots into a simple and canceled fraction
    1.72 -                           with normalform [2].*)
    1.73 -*)
    1.74 -  val norm_rational_ : theory -> term -> (term * term list) option
    1.75 -  val polynomial2expanded : term -> term option
    1.76 -  val rational_erls : 
    1.77 -      rls             (*.evaluates an arbitrary rational term with numerals.*)
    1.78 -
    1.79 -(*WN0210???SK: fehlen Funktionen, die exportiert werden sollen ? *)
    1.80 -end
    1.81 -
    1.82 -(*.**************************************************************************
    1.83 -survey on the functions
    1.84 -~~~~~~~~~~~~~~~~~~~~~~~
    1.85 - [2] 'polynomial'   :rls               | [3]'expanded_term':rls
    1.86 ---------------------:------------------+-------------------:-----------------
    1.87 - factout_p_         :                  | factout_          :
    1.88 - cancel_p_          :                  | cancel_           :
    1.89 -                    :cancel_p          |                   :cancel
    1.90 ---------------------:------------------+-------------------:-----------------
    1.91 - common_nominator_p_:                  | common_nominator_ :
    1.92 -                    :common_nominator_p|                   :common_nominator
    1.93 - add_fraction_p_    :                  | add_fraction_     :
    1.94 ---------------------:------------------+-------------------:-----------------
    1.95 -???SK                 :norm_rational_p   |                   :norm_rational
    1.96 -
    1.97 -This survey shows only the principal functions for reuse, and the identifiers 
    1.98 -of the rls exported. The list below shows some more useful functions.
    1.99 -
   1.100 -
   1.101 -conversion from Isabelle-term to internal representation
   1.102 -~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   1.103 -
   1.104 -... BITTE FORTSETZEN ...
   1.105 -
   1.106 -polynomial2expanded = ...
   1.107 -expanded2polynomial = ...
   1.108 -
   1.109 -remark: polynomial2expanded o expanded2polynomial = I, 
   1.110 -        where 'o' is function chaining, and 'I' is identity WN0210???SK
   1.111 -
   1.112 -functions for greatest common divisor and canceling
   1.113 -~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   1.114 -mv_gcd
   1.115 -factout_
   1.116 -factout_p_
   1.117 -cancel_
   1.118 -cancel_p_
   1.119 -
   1.120 -functions for least common multiple and addition of fractions
   1.121 -~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   1.122 -mv_lcm
   1.123 -common_nominator_
   1.124 -common_nominator_p_
   1.125 -add_fraction_       (*.add 2 or more fractions.*)
   1.126 -add_fraction_p_     (*.add 2 or more fractions.*)
   1.127 -
   1.128 -functions for normalform of rationals
   1.129 -~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   1.130 -WN0210???SK interne Funktionen f"ur norm_rational: 
   1.131 -          schaffen diese SML-Funktionen wirklich ganz allgemeine Terme ?
   1.132 -
   1.133 -norm_rational_
   1.134 -norm_expanded_rat_
   1.135 -
   1.136 -**************************************************************************.*)
   1.137 -
   1.138 -
   1.139 -(*##*)
   1.140 -structure RationalI : RATIONALI = 
   1.141 -struct 
   1.142 -(*##*)
   1.143 -
   1.144 -infix mem ins union; (*WN100819 updating to Isabelle2009-2*)
   1.145 -fun x mem [] = false
   1.146 -  | x mem (y :: ys) = x = y orelse x mem ys;
   1.147 -fun (x ins xs) = if x mem xs then xs else x :: xs;
   1.148 -fun xs union [] = xs
   1.149 -  | [] union ys = ys
   1.150 -  | (x :: xs) union ys = xs union (x ins ys);
   1.151 -
   1.152 -(*. gcd of integers .*)
   1.153 -(* die gcd Funktion von Isabelle funktioniert nicht richtig !!! *)
   1.154 -fun gcd_int a b = if b=0 then a
   1.155 -		  else gcd_int b (a mod b);
   1.156 -
   1.157 -(*. univariate polynomials (uv) .*)
   1.158 -(*. univariate polynomials are represented as a list of the coefficent in reverse maximum degree order .*)
   1.159 -(*. 5 * x^5 + 4 * x^3 + 2 * x^2 + x + 19 => [19,1,2,4,0,5] .*)
   1.160 -type uv_poly = int list;
   1.161 -
   1.162 -(*. adds two uv polynomials .*)
   1.163 -fun uv_mod_add_poly ([]:uv_poly,p2:uv_poly) = p2:uv_poly 
   1.164 -  | uv_mod_add_poly (p1,[]) = p1
   1.165 -  | uv_mod_add_poly (x::p1,y::p2) = (x+y)::(uv_mod_add_poly(p1,p2)); 
   1.166 -
   1.167 -(*. multiplies a uv polynomial with a skalar s .*)
   1.168 -fun uv_mod_smul_poly ([]:uv_poly,s:int) = []:uv_poly 
   1.169 -  | uv_mod_smul_poly (x::p,s) = (x*s)::(uv_mod_smul_poly(p,s)); 
   1.170 -
   1.171 -(*. calculates the remainder of a polynomial divided by a skalar s .*)
   1.172 -fun uv_mod_rem_poly ([]:uv_poly,s) = []:uv_poly 
   1.173 -  | uv_mod_rem_poly (x::p,s) = (x mod s)::(uv_mod_smul_poly(p,s)); 
   1.174 -
   1.175 -(*. calculates the degree of a uv polynomial .*)
   1.176 -fun uv_mod_deg ([]:uv_poly) = 0  
   1.177 -  | uv_mod_deg p = length(p)-1;
   1.178 -
   1.179 -(*. calculates the remainder of x/p and represents it as value between -p/2 and p/2 .*)
   1.180 -fun uv_mod_mod2(x,p)=
   1.181 -    let
   1.182 -	val y=(x mod p);
   1.183 -    in
   1.184 -	if (y)>(p div 2) then (y)-p else 
   1.185 -	    (
   1.186 -	     if (y)<(~p div 2) then p+(y) else (y)
   1.187 -	     )
   1.188 -    end;
   1.189 -
   1.190 -(*.calculates the remainder for each element of a integer list divided by p.*)  
   1.191 -fun uv_mod_list_modp [] p = [] 
   1.192 -  | uv_mod_list_modp (x::xs) p = (uv_mod_mod2(x,p))::(uv_mod_list_modp xs p);
   1.193 -
   1.194 -(*. appends an integer at the end of a integer list .*)
   1.195 -fun uv_mod_null (p1:int list,0) = p1 
   1.196 -  | uv_mod_null (p1:int list,n1:int) = uv_mod_null(p1,n1-1) @ [0];
   1.197 -
   1.198 -(*. uv polynomial division, result is (quotient, remainder) .*)
   1.199 -(*. only for uv_mod_divides .*)
   1.200 -(* FIXME: Division von x^9+x^5+1 durch x-1000 funktioniert nicht integer zu klein  *)
   1.201 -fun uv_mod_pdiv (p1:uv_poly) ([]:uv_poly) = raise error ("RATIONALS_UV_MOD_PDIV_EXCEPTION: division by zero")
   1.202 -  | uv_mod_pdiv p1 [x] = 
   1.203 -    let
   1.204 -	val xs=ref [];
   1.205 -    in
   1.206 -	if x<>0 then 
   1.207 -	    (
   1.208 -	     xs:=(uv_mod_rem_poly(p1,x));
   1.209 -	     while length(!xs)>0 andalso hd(!xs)=0 do xs:=tl(!xs)
   1.210 -	     )
   1.211 -	else raise error ("RATIONALS_UV_MOD_PDIV_EXCEPTION: division by zero");
   1.212 -	([]:uv_poly,!xs:uv_poly)
   1.213 -    end
   1.214 -  | uv_mod_pdiv p1 p2 =  
   1.215 -    let
   1.216 -	val n= uv_mod_deg(p2);
   1.217 -	val m= ref (uv_mod_deg(p1));
   1.218 -	val p1'=ref (rev(p1));
   1.219 -	val p2'=(rev(p2));
   1.220 -	val lc2=hd(p2');
   1.221 -	val q=ref [];
   1.222 -	val c=ref 0;
   1.223 -	val output=ref ([],[]);
   1.224 -    in
   1.225 -	(
   1.226 -	 if (!m)=0 orelse p2=[0] then raise error ("RATIONALS_UV_MOD_PDIV_EXCEPTION: Division by zero") 
   1.227 -	 else
   1.228 -	     (
   1.229 -	      if (!m)<n then 
   1.230 -		  (
   1.231 -		   output:=([0],p1) 
   1.232 -		   ) 
   1.233 -	      else
   1.234 -		  (
   1.235 -		   while (!m)>=n do
   1.236 -		       (
   1.237 -			c:=hd(!p1') div hd(p2');
   1.238 -			if !c<>0 then
   1.239 -			    (
   1.240 -			     p1':=uv_mod_add_poly(!p1',uv_mod_null(uv_mod_smul_poly(p2',~(!c)),!m-n));
   1.241 -			     while length(!p1')>0 andalso hd(!p1')=0  do p1':= tl(!p1');
   1.242 -			     m:=uv_mod_deg(!p1')
   1.243 -			     )
   1.244 -			else m:=0
   1.245 -			);
   1.246 -    		   output:=(rev(!q),rev(!p1'))
   1.247 -		   )
   1.248 -	      );
   1.249 -	     !output
   1.250 -	 )
   1.251 -    end;
   1.252 -
   1.253 -(*. divides p1 by p2 in Zp .*)
   1.254 -fun uv_mod_pdivp (p1:uv_poly) (p2:uv_poly) p =  
   1.255 -    let
   1.256 -	val n=uv_mod_deg(p2);
   1.257 -	val m=ref (uv_mod_deg(uv_mod_list_modp p1 p));
   1.258 -	val p1'=ref (rev(p1));
   1.259 -	val p2'=(rev(uv_mod_list_modp p2 p));
   1.260 -	val lc2=hd(p2');
   1.261 -	val q=ref [];
   1.262 -	val c=ref 0;
   1.263 -	val output=ref ([],[]);
   1.264 -    in
   1.265 -	(
   1.266 -	 if (!m)=0 orelse p2=[0] then raise error ("RATIONALS_UV_MOD_PDIVP_EXCEPTION: Division by zero") 
   1.267 -	 else
   1.268 -	     (
   1.269 -	      if (!m)<n then 
   1.270 -		  (
   1.271 -		   output:=([0],p1) 
   1.272 -		   ) 
   1.273 -	      else
   1.274 -		  (
   1.275 -		   while (!m)>=n do
   1.276 -		       (
   1.277 -			c:=uv_mod_mod2(hd(!p1')*(power lc2 1), p);
   1.278 -			q:=(!c)::(!q);
   1.279 -			p1':=uv_mod_list_modp(tl(uv_mod_add_poly(uv_mod_smul_poly(!p1',lc2),
   1.280 -								  uv_mod_smul_poly(uv_mod_smul_poly(p2',hd(!p1')),~1)))) p;
   1.281 -			m:=(!m)-1
   1.282 -			);
   1.283 -		   
   1.284 -		   while !p1'<>[] andalso hd(!p1')=0 do
   1.285 -		       (
   1.286 -			p1':=tl(!p1')
   1.287 -			);
   1.288 -
   1.289 -    		   output:=(rev(uv_mod_list_modp (!q) (p)),rev(!p1'))
   1.290 -		   )
   1.291 -	      );
   1.292 -	     !output:uv_poly * uv_poly
   1.293 -	 )
   1.294 -    end;
   1.295 -
   1.296 -(*. calculates the remainder of p1/p2 .*)
   1.297 -fun uv_mod_prest (p1:uv_poly) ([]:uv_poly) = raise error("UV_MOD_PREST_EXCEPTION: Division by zero") 
   1.298 -  | uv_mod_prest [] p2 = []:uv_poly
   1.299 -  | uv_mod_prest p1 p2 = (#2(uv_mod_pdiv p1 p2));
   1.300 -
   1.301 -(*. calculates the remainder of p1/p2 in Zp .*)
   1.302 -fun uv_mod_prestp (p1:uv_poly) ([]:uv_poly) p= raise error("UV_MOD_PRESTP_EXCEPTION: Division by zero") 
   1.303 -  | uv_mod_prestp [] p2 p= []:uv_poly 
   1.304 -  | uv_mod_prestp p1 p2 p = #2(uv_mod_pdivp p1 p2 p); 
   1.305 -
   1.306 -(*. calculates the content of a uv polynomial .*)
   1.307 -fun uv_mod_cont ([]:uv_poly) = 0  
   1.308 -  | uv_mod_cont (x::p)= gcd_int x (uv_mod_cont(p));
   1.309 -
   1.310 -(*. divides each coefficient of a uv polynomial by y .*)
   1.311 -fun uv_mod_div_list (p:uv_poly,0) = raise error("UV_MOD_DIV_LIST_EXCEPTION: Division by zero") 
   1.312 -  | uv_mod_div_list ([],y)   = []:uv_poly
   1.313 -  | uv_mod_div_list (x::p,y) = (x div y)::uv_mod_div_list(p,y); 
   1.314 -
   1.315 -(*. calculates the primitiv part of a uv polynomial .*)
   1.316 -fun uv_mod_pp ([]:uv_poly) = []:uv_poly
   1.317 -  | uv_mod_pp p =  
   1.318 -    let
   1.319 -	val c=ref 0;
   1.320 -    in
   1.321 -	(
   1.322 -	 c:=uv_mod_cont(p);
   1.323 -	 
   1.324 -	 if !c=0 then raise error ("RATIONALS_UV_MOD_PP_EXCEPTION: content is 0")
   1.325 -	 else uv_mod_div_list(p,!c)
   1.326 -	)
   1.327 -    end;
   1.328 -
   1.329 -(*. gets the leading coefficient of a uv polynomial .*)
   1.330 -fun uv_mod_lc ([]:uv_poly) = 0 
   1.331 -  | uv_mod_lc p  = hd(rev(p)); 
   1.332 -
   1.333 -(*. calculates the euklidean polynomial remainder sequence in Zp .*)
   1.334 -fun uv_mod_prs_euklid_p(p1:uv_poly,p2:uv_poly,p)= 
   1.335 -    let
   1.336 -	val f =ref [];
   1.337 -	val f'=ref p2;
   1.338 -	val fi=ref [];
   1.339 -    in
   1.340 -	( 
   1.341 -	 f:=p2::p1::[]; 
   1.342 - 	 while uv_mod_deg(!f')>0 do
   1.343 -	     (
   1.344 -	      f':=uv_mod_prestp (hd(tl(!f))) (hd(!f)) p;
   1.345 -	      if (!f')<>[] then 
   1.346 -		  (
   1.347 -		   fi:=(!f');
   1.348 -		   f:=(!fi)::(!f)
   1.349 -		   )
   1.350 -	      else ()
   1.351 -	      );
   1.352 -	      (!f)
   1.353 -	 
   1.354 -	 )
   1.355 -    end;
   1.356 -
   1.357 -(*. calculates the gcd of p1 and p2 in Zp .*)
   1.358 -fun uv_mod_gcd_modp ([]:uv_poly) (p2:uv_poly) p = p2:uv_poly 
   1.359 -  | uv_mod_gcd_modp p1 [] p= p1
   1.360 -  | uv_mod_gcd_modp p1 p2 p=
   1.361 -    let
   1.362 -	val p1'=ref[];
   1.363 -	val p2'=ref[];
   1.364 -	val pc=ref[];
   1.365 -	val g=ref [];
   1.366 -	val d=ref 0;
   1.367 -	val prs=ref [];
   1.368 -    in
   1.369 -	(
   1.370 -	 if uv_mod_deg(p1)>=uv_mod_deg(p2) then
   1.371 -	     (
   1.372 -	      p1':=uv_mod_list_modp (uv_mod_pp(p1)) p;
   1.373 -	      p2':=uv_mod_list_modp (uv_mod_pp(p2)) p
   1.374 -	      )
   1.375 -	 else 
   1.376 -	     (
   1.377 -	      p1':=uv_mod_list_modp (uv_mod_pp(p2)) p;
   1.378 -	      p2':=uv_mod_list_modp (uv_mod_pp(p1)) p
   1.379 -	      );
   1.380 -	 d:=uv_mod_mod2((gcd_int (uv_mod_cont(p1))) (uv_mod_cont(p2)), p) ;
   1.381 -	 if !d>(p div 2) then d:=(!d)-p else ();
   1.382 -	 
   1.383 -	 prs:=uv_mod_prs_euklid_p(!p1',!p2',p);
   1.384 -
   1.385 -	 if hd(!prs)=[] then pc:=hd(tl(!prs))
   1.386 -	 else pc:=hd(!prs);
   1.387 -
   1.388 -	 g:=uv_mod_smul_poly(uv_mod_pp(!pc),!d);
   1.389 -	 !g
   1.390 -	 )
   1.391 -    end;
   1.392 -
   1.393 -(*. calculates the minimum of two real values x and y .*)
   1.394 -fun uv_mod_r_min(x,y):BasisLibrary.Real.real = if x>y then y else x;
   1.395 -
   1.396 -(*. calculates the minimum of two integer values x and y .*)
   1.397 -fun uv_mod_min(x,y) = if x>y then y else x;
   1.398 -
   1.399 -(*. adds the squared values of a integer list .*)
   1.400 -fun uv_mod_add_qu [] = 0.0 
   1.401 -  | uv_mod_add_qu (x::p) =  BasisLibrary.Real.fromInt(x)*BasisLibrary.Real.fromInt(x) + uv_mod_add_qu p;
   1.402 -
   1.403 -(*. calculates the euklidean norm .*)
   1.404 -fun uv_mod_norm ([]:uv_poly) = 0.0
   1.405 -  | uv_mod_norm p = Math.sqrt(uv_mod_add_qu(p));
   1.406 -
   1.407 -(*. multipies two values a and b .*)
   1.408 -fun uv_mod_multi a b = a * b;
   1.409 -
   1.410 -(*. decides if x is a prim, the list contains all primes which are lower then x .*)
   1.411 -fun uv_mod_prim(x,[])= false 
   1.412 -  | uv_mod_prim(x,[y])=if ((x mod y) <> 0) then true
   1.413 -		else false
   1.414 -  | uv_mod_prim(x,y::ys) = if uv_mod_prim(x,[y])
   1.415 -			then 
   1.416 -			    if uv_mod_prim(x,ys) then true 
   1.417 -			    else false
   1.418 -		    else false;
   1.419 -
   1.420 -(*. gets the first prime, which is greater than p and does not divide g .*)
   1.421 -fun uv_mod_nextprime(g,p)= 
   1.422 -    let
   1.423 -	val list=ref [2];
   1.424 -	val exit=ref 0;
   1.425 -	val i = ref 2
   1.426 -    in
   1.427 -	while (!i<p) do (* calculates the primes lower then p *)
   1.428 -	    (
   1.429 -	     if uv_mod_prim(!i,!list) then
   1.430 -		 (
   1.431 -		  if (p mod !i <> 0)
   1.432 -		      then
   1.433 -			  (
   1.434 -			   list:= (!i)::(!list);
   1.435 -			   i:= (!i)+1
   1.436 -			   )
   1.437 -		  else i:=(!i)+1
   1.438 -		  )
   1.439 -	     else i:= (!i)+1
   1.440 -		 );
   1.441 -	    i:=(p+1);
   1.442 -	    while (!exit=0) do   (* calculate next prime which does not divide g *)
   1.443 -	    (
   1.444 -	     if uv_mod_prim(!i,!list) then
   1.445 -		 (
   1.446 -		  if (g mod !i <> 0)
   1.447 -		      then
   1.448 -			  (
   1.449 -			   list:= (!i)::(!list);
   1.450 -			   exit:= (!i)
   1.451 -			   )
   1.452 -		  else i:=(!i)+1
   1.453 -		      )
   1.454 -	     else i:= (!i)+1
   1.455 -		 ); 
   1.456 -	    !exit
   1.457 -    end;
   1.458 -
   1.459 -(*. decides if p1 is a factor of p2 in Zp .*)
   1.460 -fun uv_mod_dividesp ([]:uv_poly) (p2:uv_poly) p= raise error("UV_MOD_DIVIDESP: Division by zero") 
   1.461 -  | uv_mod_dividesp p1 p2 p= if uv_mod_prestp p2 p1 p = [] then true else false;
   1.462 -
   1.463 -(*. decides if p1 is a factor of p2 .*)
   1.464 -fun uv_mod_divides ([]:uv_poly) (p2:uv_poly) = raise error("UV_MOD_DIVIDES: Division by zero")
   1.465 -  | uv_mod_divides p1 p2 = if uv_mod_prest p2 p1  = [] then true else false;
   1.466 -
   1.467 -(*. chinese remainder algorithm .*)
   1.468 -fun uv_mod_cra2(r1,r2,m1,m2)=     
   1.469 -    let 
   1.470 -	val c=ref 0;
   1.471 -	val r1'=ref 0;
   1.472 -	val d=ref 0;
   1.473 -	val a=ref 0;
   1.474 -    in
   1.475 -	(
   1.476 -	 while (uv_mod_mod2((!c)*m1,m2))<>1 do 
   1.477 -	     (
   1.478 -	      c:=(!c)+1
   1.479 -	      );
   1.480 -	 r1':= uv_mod_mod2(r1,m1);
   1.481 -	 d:=uv_mod_mod2(((r2-(!r1'))*(!c)),m2);
   1.482 -	 !r1'+(!d)*m1    
   1.483 -	 )
   1.484 -    end;
   1.485 -
   1.486 -(*. applies the chinese remainder algorithmen to the coefficients of x1 and x2 .*)
   1.487 -fun uv_mod_cra_2 ([],[],m1,m2) = [] 
   1.488 -  | uv_mod_cra_2 ([],x2,m1,m2) = raise error("UV_MOD_CRA_2_EXCEPTION: invalid call x1")
   1.489 -  | uv_mod_cra_2 (x1,[],m1,m2) = raise error("UV_MOD_CRA_2_EXCEPTION: invalid call x2")
   1.490 -  | uv_mod_cra_2 (x1::x1s,x2::x2s,m1,m2) = (uv_mod_cra2(x1,x2,m1,m2))::(uv_mod_cra_2(x1s,x2s,m1,m2));
   1.491 -
   1.492 -(*. calculates the gcd of two uv polynomials p1' and p2' with the modular algorithm .*)
   1.493 -fun uv_mod_gcd (p1':uv_poly) (p2':uv_poly) =
   1.494 -    let 
   1.495 -	val p1=ref (uv_mod_pp(p1'));
   1.496 -	val p2=ref (uv_mod_pp(p2'));
   1.497 -	val c=gcd_int (uv_mod_cont(p1')) (uv_mod_cont(p2'));
   1.498 -	val temp=ref [];
   1.499 -	val cp=ref [];
   1.500 -	val qp=ref [];
   1.501 -	val q=ref[];
   1.502 -	val pn=ref 0;
   1.503 -	val d=ref 0;
   1.504 -	val g1=ref 0;
   1.505 -	val p=ref 0;    
   1.506 -	val m=ref 0;
   1.507 -	val exit=ref 0;
   1.508 -	val i=ref 1;
   1.509 -    in
   1.510 -	if length(!p1)>length(!p2) then ()
   1.511 -	else 
   1.512 -	    (
   1.513 -	     temp:= !p1;
   1.514 -	     p1:= !p2;
   1.515 -	     p2:= !temp
   1.516 -	     );
   1.517 -
   1.518 -	 
   1.519 -	d:=gcd_int (uv_mod_lc(!p1)) (uv_mod_lc(!p2));
   1.520 -	g1:=uv_mod_lc(!p1)*uv_mod_lc(!p2);
   1.521 -	p:=4;
   1.522 -	
   1.523 -	m:=BasisLibrary.Real.ceil(2.0 *   
   1.524 -				  BasisLibrary.Real.fromInt(!d) *
   1.525 -				  BasisLibrary.Real.fromInt(power 2 (uv_mod_min(uv_mod_deg(!p2),uv_mod_deg(!p1)))) *  
   1.526 -				  BasisLibrary.Real.fromInt(!d) * 
   1.527 -				  uv_mod_r_min(uv_mod_norm(!p1) / BasisLibrary.Real.fromInt(abs(uv_mod_lc(!p1))),
   1.528 -					uv_mod_norm(!p2) / BasisLibrary.Real.fromInt(abs(uv_mod_lc(!p2))))); 
   1.529 -
   1.530 -	while (!exit=0) do  
   1.531 -	    (
   1.532 -	     p:=uv_mod_nextprime(!d,!p);
   1.533 -	     cp:=(uv_mod_gcd_modp (uv_mod_list_modp(!p1) (!p)) (uv_mod_list_modp(!p2) (!p)) (!p)) ;
   1.534 -	     if abs(uv_mod_lc(!cp))<>1 then  (* leading coefficient = 1 ? *)
   1.535 -		 (
   1.536 -		  i:=1;
   1.537 -		  while (!i)<(!p) andalso (abs(uv_mod_mod2((uv_mod_lc(!cp)*(!i)),(!p)))<>1) do
   1.538 -		      (
   1.539 -		       i:=(!i)+1
   1.540 -		       );
   1.541 -		      cp:=uv_mod_list_modp (map (uv_mod_multi (!i)) (!cp)) (!p) 
   1.542 -		  )
   1.543 -	     else ();
   1.544 -
   1.545 -	     qp:= ((map (uv_mod_multi (uv_mod_mod2(!d,!p)))) (!cp));
   1.546 -
   1.547 -	     if uv_mod_deg(!qp)=0 then (q:=[1]; exit:=1) else ();
   1.548 -
   1.549 -	     pn:=(!p);
   1.550 -	     q:=(!qp);
   1.551 -
   1.552 -	     while !pn<= !m andalso !m>(!p) andalso !exit=0 do
   1.553 -		 (
   1.554 -		  p:=uv_mod_nextprime(!d,!p);
   1.555 - 		  cp:=(uv_mod_gcd_modp (uv_mod_list_modp(!p1) (!p)) (uv_mod_list_modp(!p2) (!p)) (!p)); 
   1.556 - 		  if uv_mod_lc(!cp)<>1 then  (* leading coefficient = 1 ? *)
   1.557 - 		      (
   1.558 - 		       i:=1;
   1.559 - 		       while (!i)<(!p) andalso ((uv_mod_mod2((uv_mod_lc(!q)*(!i)),(!p)))<>1) do
   1.560 - 			   (
   1.561 - 			    i:=(!i)+1
   1.562 -		           );
   1.563 -		       cp:=uv_mod_list_modp (map (uv_mod_multi (!i)) (!cp)) (!p)
   1.564 - 		      )
   1.565 - 		  else ();    
   1.566 - 		 
   1.567 -		  qp:=uv_mod_list_modp ((map (uv_mod_multi (uv_mod_mod2(!d,!p)))) (!cp)  ) (!p);
   1.568 - 		  if uv_mod_deg(!qp)>uv_mod_deg(!q) then
   1.569 - 		      (
   1.570 - 		       (*print("degree to high!!!\n")*)
   1.571 - 		       )
   1.572 - 		  else
   1.573 - 		      (
   1.574 - 		       if uv_mod_deg(!qp)=uv_mod_deg(!q) then
   1.575 - 			   (
   1.576 - 			    q:=uv_mod_cra_2(!q,!qp,!pn,!p);
   1.577 -			    pn:=(!pn) * !p;
   1.578 -			    q:=uv_mod_pp(uv_mod_list_modp (!q) (!pn)); (* found already gcd ? *)
   1.579 -			    if (uv_mod_divides (!q) (p1')) andalso (uv_mod_divides (!q) (p2')) then (exit:=1) else ()
   1.580 -		 	    )
   1.581 -		       else
   1.582 -			   (
   1.583 -			    if  uv_mod_deg(!qp)<uv_mod_deg(!q) then
   1.584 -				(
   1.585 -				 pn:= !p;
   1.586 -				 q:= !qp
   1.587 -				 )
   1.588 -			    else ()
   1.589 -			    )
   1.590 -		       )
   1.591 -		  );
   1.592 - 	     q:=uv_mod_pp(uv_mod_list_modp (!q) (!pn));
   1.593 -	     if (uv_mod_divides (!q) (p1')) andalso (uv_mod_divides (!q) (p2')) then exit:=1 else ()
   1.594 -	     );
   1.595 -	    uv_mod_smul_poly(!q,c):uv_poly
   1.596 -    end;
   1.597 -
   1.598 -(*. multivariate polynomials .*)
   1.599 -(*. multivariate polynomials are represented as a list of the pairs, 
   1.600 - first is the coefficent and the second is a list of the exponents .*)
   1.601 -(*. 5 * x^5 * y^3 + 4 * x^3 * z^2 + 2 * x^2 * y * z^3 - z - 19 
   1.602 - => [(5,[5,3,0]),(4,[3,0,2]),(2,[2,1,3]),(~1,[0,0,1]),(~19,[0,0,0])] .*)
   1.603 -
   1.604 -(*. global variables .*)
   1.605 -(*. order indicators .*)
   1.606 -val LEX_=0; (* lexicographical term order *)
   1.607 -val GGO_=1; (* greatest degree order *)
   1.608 -
   1.609 -(*. datatypes for internal representation.*)
   1.610 -type mv_monom = (int *      (*.coefficient or the monom.*)
   1.611 -		 int list); (*.list of exponents)      .*)
   1.612 -fun mv_monom2str (i, is) = "("^ int2str i^"," ^ ints2str' is ^ ")";
   1.613 -
   1.614 -type mv_poly = mv_monom list; 
   1.615 -fun mv_poly2str p = (strs2str' o (map mv_monom2str)) p;
   1.616 -
   1.617 -(*. help function for monom_greater and geq .*)
   1.618 -fun mv_mg_hlp([]) = EQUAL 
   1.619 -  | mv_mg_hlp(x::list)=if x<0 then LESS
   1.620 -		    else if x>0 then GREATER
   1.621 -			 else mv_mg_hlp(list);
   1.622 -
   1.623 -(*. adds a list of values .*)
   1.624 -fun mv_addlist([]) = 0
   1.625 -  | mv_addlist(p1) = hd(p1)+mv_addlist(tl(p1));
   1.626 -			   
   1.627 -(*. tests if the monomial M1 is greater as the monomial M2 and returns a boolean value .*)
   1.628 -(*. 2 orders are implemented LEX_/GGO_ (lexigraphical/greatest degree order) .*)
   1.629 -fun mv_monom_greater((M1x,M1l):mv_monom,(M2x,M2l):mv_monom,order)=
   1.630 -    if order=LEX_ then
   1.631 -	( 
   1.632 -	 if length(M1l)<>length(M2l) then raise error ("RATIONALS_MV_MONOM_GREATER_EXCEPTION: Order error")
   1.633 -	 else if (mv_mg_hlp((map op- (M1l~~M2l)))<>GREATER) then false else true
   1.634 -	     )
   1.635 -    else
   1.636 -	if order=GGO_ then
   1.637 -	    ( 
   1.638 -	     if length(M1l)<>length(M2l) then raise error ("RATIONALS_MV_MONOM_GREATER_EXCEPTION: Order error")
   1.639 -	     else 
   1.640 -		 if mv_addlist(M1l)=mv_addlist(M2l)  then if (mv_mg_hlp((map op- (M1l~~M2l)))<>GREATER) then false else true
   1.641 -		 else if mv_addlist(M1l)>mv_addlist(M2l) then true else false
   1.642 -	     )
   1.643 -	else raise error ("RATIONALS_MV_MONOM_GREATER_EXCEPTION: Wrong Order");
   1.644 -		   
   1.645 -(*. tests if the monomial X is greater as the monomial Y and returns a order value (GREATER,EQUAL,LESS) .*)
   1.646 -(*. 2 orders are implemented LEX_/GGO_ (lexigraphical/greatest degree order) .*)
   1.647 -fun mv_geq order ((x1,x):mv_monom,(x2,y):mv_monom) =
   1.648 -let 
   1.649 -    val temp=ref EQUAL;
   1.650 -in
   1.651 -    if order=LEX_ then
   1.652 -	(
   1.653 -	 if length(x)<>length(y) then 
   1.654 -	     raise error ("RATIONALS_MV_GEQ_EXCEPTION: Order error")
   1.655 -	 else 
   1.656 -	     (
   1.657 -	      temp:=mv_mg_hlp((map op- (x~~y)));
   1.658 -	      if !temp=EQUAL then 
   1.659 -		  ( if x1=x2 then EQUAL 
   1.660 -		    else if x1>x2 then GREATER
   1.661 -			 else LESS
   1.662 -			     )
   1.663 -	      else (!temp)
   1.664 -	      )
   1.665 -	     )
   1.666 -    else 
   1.667 -	if order=GGO_ then 
   1.668 -	    (
   1.669 -	     if length(x)<>length(y) then 
   1.670 -	      raise error ("RATIONALS_MV_GEQ_EXCEPTION: Order error")
   1.671 -	     else 
   1.672 -		 if mv_addlist(x)=mv_addlist(y) then 
   1.673 -		     (mv_mg_hlp((map op- (x~~y))))
   1.674 -		 else if mv_addlist(x)>mv_addlist(y) then GREATER else LESS
   1.675 -		     )
   1.676 -	else raise error ("RATIONALS_MV_GEQ_EXCEPTION: Wrong Order")
   1.677 -end;
   1.678 -
   1.679 -(*. cuts the first variable from a polynomial .*)
   1.680 -fun mv_cut([]:mv_poly)=[]:mv_poly
   1.681 -  | mv_cut((x,[])::list) = raise error ("RATIONALS_MV_CUT_EXCEPTION: Invalid list ")
   1.682 -  | mv_cut((x,y::ys)::list)=(x,ys)::mv_cut(list);
   1.683 -	    
   1.684 -(*. leading power product .*)
   1.685 -fun mv_lpp([]:mv_poly,order)  = []
   1.686 -  | mv_lpp([(x,y)],order) = y
   1.687 -  | mv_lpp(p1,order)  = #2(hd(rev(sort (mv_geq order) p1)));
   1.688 -    
   1.689 -(*. leading monomial .*)
   1.690 -fun mv_lm([]:mv_poly,order)  = (0,[]):mv_monom
   1.691 -  | mv_lm([x],order) = x 
   1.692 -  | mv_lm(p1,order)  = hd(rev(sort (mv_geq order) p1));
   1.693 -    
   1.694 -(*. leading coefficient in term order .*)
   1.695 -fun mv_lc2([]:mv_poly,order)  = 0
   1.696 -  | mv_lc2([(x,y)],order) = x
   1.697 -  | mv_lc2(p1,order)  = #1(hd(rev(sort (mv_geq order) p1)));
   1.698 -
   1.699 -
   1.700 -(*. reverse the coefficients in mv polynomial .*)
   1.701 -fun mv_rev_to([]:mv_poly) = []:mv_poly
   1.702 -  | mv_rev_to((c,e)::xs) = (c,rev(e))::mv_rev_to(xs);
   1.703 -
   1.704 -(*. leading coefficient in reverse term order .*)
   1.705 -fun mv_lc([]:mv_poly,order)  = []:mv_poly 
   1.706 -  | mv_lc([(x,y)],order) = mv_rev_to(mv_cut(mv_rev_to([(x,y)])))
   1.707 -  | mv_lc(p1,order)  = 
   1.708 -    let
   1.709 -	val p1o=ref (rev(sort (mv_geq order) (mv_rev_to(p1))));
   1.710 -	val lp=hd(#2(hd(!p1o)));
   1.711 -	val lc=ref [];
   1.712 -    in
   1.713 -	(
   1.714 -	 while (length(!p1o)>0 andalso hd(#2(hd(!p1o)))=lp) do
   1.715 -	     (
   1.716 -	      lc:=hd(mv_cut([hd(!p1o)]))::(!lc);
   1.717 -	      p1o:=tl(!p1o)
   1.718 -	      );
   1.719 -	 if !lc=[] then raise error ("RATIONALS_MV_LC_EXCEPTION: lc is empty") else ();
   1.720 -	 mv_rev_to(!lc)
   1.721 -	 )
   1.722 -    end;
   1.723 -
   1.724 -(*. compares two powerproducts .*)
   1.725 -fun mv_monom_equal((_,xlist):mv_monom,(_,ylist):mv_monom) = (foldr and_) (((map op=) (xlist~~ylist)),true);
   1.726 -    
   1.727 -(*. help function for mv_add .*)
   1.728 -fun mv_madd([]:mv_poly,[]:mv_poly,order) = []:mv_poly
   1.729 -  | mv_madd([(0,_)],p2,order) = p2
   1.730 -  | mv_madd(p1,[(0,_)],order) = p1  
   1.731 -  | mv_madd([],p2,order) = p2
   1.732 -  | mv_madd(p1,[],order) = p1
   1.733 -  | mv_madd(p1,p2,order) = 
   1.734 -    (
   1.735 -     if mv_monom_greater(hd(p1),hd(p2),order) 
   1.736 -	 then hd(p1)::mv_madd(tl(p1),p2,order)
   1.737 -     else if mv_monom_equal(hd(p1),hd(p2)) 
   1.738 -	      then if mv_lc2(p1,order)+mv_lc2(p2,order)<>0 
   1.739 -		       then (mv_lc2(p1,order)+mv_lc2(p2,order),mv_lpp(p1,order))::mv_madd(tl(p1),tl(p2),order)
   1.740 -		   else mv_madd(tl(p1),tl(p2),order)
   1.741 -	  else hd(p2)::mv_madd(p1,tl(p2),order)
   1.742 -	      )
   1.743 -	      
   1.744 -(*. adds two multivariate polynomials .*)
   1.745 -fun mv_add([]:mv_poly,p2:mv_poly,order) = p2
   1.746 -  | mv_add(p1,[],order) = p1
   1.747 -  | mv_add(p1,p2,order) = mv_madd(rev(sort (mv_geq order) p1),rev(sort (mv_geq order) p2), order);
   1.748 -
   1.749 -(*. monom multiplication .*)
   1.750 -fun mv_mmul((x1,y1):mv_monom,(x2,y2):mv_monom)=(x1*x2,(map op+) (y1~~y2)):mv_monom;
   1.751 -
   1.752 -(*. deletes all monomials with coefficient 0 .*)
   1.753 -fun mv_shorten([]:mv_poly,order) = []:mv_poly
   1.754 -  | mv_shorten(x::xs,order)=mv_madd([x],mv_shorten(xs,order),order);
   1.755 -
   1.756 -(*. zeros a list .*)
   1.757 -fun mv_null2([])=[]
   1.758 -  | mv_null2(x::l)=0::mv_null2(l);
   1.759 -
   1.760 -(*. multiplies two multivariate polynomials .*)
   1.761 -fun mv_mul([]:mv_poly,[]:mv_poly,_) = []:mv_poly
   1.762 -  | mv_mul([],y::p2,_) = [(0,mv_null2(#2(y)))]
   1.763 -  | mv_mul(x::p1,[],_) = [(0,mv_null2(#2(x)))] 
   1.764 -  | mv_mul(x::p1,y::p2,order) = mv_shorten(rev(sort (mv_geq order) (mv_mmul(x,y) :: (mv_mul(p1,y::p2,order) @
   1.765 -									    mv_mul([x],p2,order)))),order);
   1.766 -
   1.767 -(*. gets the maximum value of a list .*)
   1.768 -fun mv_getmax([])=0
   1.769 -  | mv_getmax(x::p1)= let 
   1.770 -		       val m=mv_getmax(p1);
   1.771 -		   in
   1.772 -		       if m>x then m
   1.773 -		       else x
   1.774 -		   end;
   1.775 -(*. calculates the maximum degree of an multivariate polynomial .*)
   1.776 -fun mv_grad([]:mv_poly) = 0 
   1.777 -  | mv_grad(p1:mv_poly)= mv_getmax((map mv_addlist) ((map #2) p1));
   1.778 -
   1.779 -(*. converts the sign of a value .*)
   1.780 -fun mv_minus(x)=(~1) * x;
   1.781 -
   1.782 -(*. converts the sign of all coefficients of a polynomial .*)
   1.783 -fun mv_minus2([]:mv_poly)=[]:mv_poly
   1.784 -  | mv_minus2(p1)=(mv_minus(#1(hd(p1))),#2(hd(p1)))::(mv_minus2(tl(p1)));
   1.785 -
   1.786 -(*. searches for a negativ value in a list .*)
   1.787 -fun mv_is_negativ([])=false
   1.788 -  | mv_is_negativ(x::xs)=if x<0 then true else mv_is_negativ(xs);
   1.789 -
   1.790 -(*. division of monomials .*)
   1.791 -fun mv_mdiv((0,[]):mv_monom,_:mv_monom)=(0,[]):mv_monom
   1.792 -  | mv_mdiv(_,(0,[]))= raise error ("RATIONALS_MV_MDIV_EXCEPTION Division by 0 ")
   1.793 -  | mv_mdiv(p1:mv_monom,p2:mv_monom)= 
   1.794 -    let
   1.795 -	val c=ref (#1(p2));
   1.796 -	val pp=ref [];
   1.797 -    in 
   1.798 -	(
   1.799 -	 if !c=0 then raise error("MV_MDIV_EXCEPTION Dividing by zero")
   1.800 -	 else c:=(#1(p1) div #1(p2));
   1.801 -	     if #1(p2)<>0 then 
   1.802 -		 (
   1.803 -		  pp:=(#2(mv_mmul((1,#2(p1)),(1,(map mv_minus) (#2(p2))))));
   1.804 -		  if mv_is_negativ(!pp) then (0,!pp)
   1.805 -		  else (!c,!pp) 
   1.806 -		      )
   1.807 -	     else raise error("MV_MDIV_EXCEPTION Dividing by empty Polynom")
   1.808 -		 )
   1.809 -    end;
   1.810 -
   1.811 -(*. prints a polynom for (internal use only) .*)
   1.812 -fun mv_print_poly([]:mv_poly)=print("[]\n")
   1.813 -  | mv_print_poly((x,y)::[])= print("("^BasisLibrary.Int.toString(x)^","^ints2str(y)^")\n")
   1.814 -  | mv_print_poly((x,y)::p1) = (print("("^BasisLibrary.Int.toString(x)^","^ints2str(y)^"),");mv_print_poly(p1));
   1.815 -
   1.816 -
   1.817 -(*. division of two multivariate polynomials .*) 
   1.818 -fun mv_division([]:mv_poly,g:mv_poly,order)=([]:mv_poly,[]:mv_poly)
   1.819 -  | mv_division(f,[],order)= raise error ("RATIONALS_MV_DIVISION_EXCEPTION Division by zero")
   1.820 -  | mv_division(f,g,order)=
   1.821 -    let 
   1.822 -	val r=ref [];
   1.823 -	val q=ref [];
   1.824 -	val g'=ref [];
   1.825 -	val k=ref 0;
   1.826 -	val m=ref (0,[0]);
   1.827 -	val exit=ref 0;
   1.828 -    in
   1.829 -	r := rev(sort (mv_geq order) (mv_shorten(f,order)));
   1.830 -	g':= rev(sort (mv_geq order) (mv_shorten(g,order)));
   1.831 -	if #1(hd(!g'))=0 then raise error("RATIONALS_MV_DIVISION_EXCEPTION: Dividing by zero") else ();
   1.832 -	if  (mv_monom_greater (hd(!g'),hd(!r),order)) then ([(0,mv_null2(#2(hd(f))))],(!r))
   1.833 -	else
   1.834 -	    (
   1.835 -	     exit:=0;
   1.836 -	     while (if (!exit)=0 then not(mv_monom_greater (hd(!g'),hd(!r),order)) else false) do
   1.837 -		 (
   1.838 -		  if (#1(mv_lm(!g',order)))<>0 then m:=mv_mdiv(mv_lm(!r,order),mv_lm(!g',order))
   1.839 -		  else raise error ("RATIONALS_MV_DIVISION_EXCEPTION: Dividing by zero");	  
   1.840 -		  if #1(!m)<>0 then
   1.841 -		      ( 
   1.842 -		       q:=(!m)::(!q);
   1.843 -		       r:=mv_add((!r),mv_minus2(mv_mul(!g',[!m],order)),order)
   1.844 -		       )
   1.845 -		  else exit:=1;
   1.846 -		  if (if length(!r)<>0 then length(!g')<>0 else false) then ()
   1.847 -		  else (exit:=1)
   1.848 -		  );
   1.849 -		 (rev(!q),!r)
   1.850 -		 )
   1.851 -    end;
   1.852 -
   1.853 -(*. multiplies a polynomial with an integer .*)
   1.854 -fun mv_skalar_mul([]:mv_poly,c) = []:mv_poly
   1.855 -  | mv_skalar_mul((x,y)::p1,c) = ((x * c),y)::mv_skalar_mul(p1,c); 
   1.856 -
   1.857 -(*. inserts the a first variable into an polynomial with exponent v .*)
   1.858 -fun mv_correct([]:mv_poly,v:int)=[]:mv_poly
   1.859 -  | mv_correct((x,y)::list,v:int)=(x,v::y)::mv_correct(list,v);
   1.860 -
   1.861 -(*. multivariate case .*)
   1.862 -
   1.863 -(*. decides if x is a factor of y .*)
   1.864 -fun mv_divides([]:mv_poly,[]:mv_poly)=  raise error("RATIONALS_MV_DIVIDES_EXCEPTION: division by zero")
   1.865 -  | mv_divides(x,[]) =  raise error("RATIONALS_MV_DIVIDES_EXCEPTION: division by zero")
   1.866 -  | mv_divides(x:mv_poly,y:mv_poly) = #2(mv_division(y,x,LEX_))=[];
   1.867 -
   1.868 -(*. gets the maximum of a and b .*)
   1.869 -fun mv_max(a,b) = if a>b then a else b;
   1.870 -
   1.871 -(*. gets the maximum exponent of a mv polynomial in the lexicographic term order .*)
   1.872 -fun mv_deg([]:mv_poly) = 0  
   1.873 -  | mv_deg(p1)=
   1.874 -    let
   1.875 -	val p1'=mv_shorten(p1,LEX_);
   1.876 -    in
   1.877 -	if length(p1')=0 then 0 
   1.878 -	else mv_max(hd(#2(hd(p1'))),mv_deg(tl(p1')))
   1.879 -    end;
   1.880 -
   1.881 -(*. gets the maximum exponent of a mv polynomial in the reverse lexicographic term order .*)
   1.882 -fun mv_deg2([]:mv_poly) = 0
   1.883 -  | mv_deg2(p1)=
   1.884 -    let
   1.885 -	val p1'=mv_shorten(p1,LEX_);
   1.886 -    in
   1.887 -	if length(p1')=0 then 0 
   1.888 -	else mv_max(hd(rev(#2(hd(p1')))),mv_deg2(tl(p1')))
   1.889 -    end;
   1.890 -
   1.891 -(*. evaluates the mv polynomial at the value v of the main variable .*)
   1.892 -fun mv_subs([]:mv_poly,v) = []:mv_poly
   1.893 -  | mv_subs((c,e)::p1:mv_poly,v) = mv_skalar_mul(mv_cut([(c,e)]),power v (hd(e))) @ mv_subs(p1,v);
   1.894 -
   1.895 -(*. calculates the content of a uv-polynomial in mv-representation .*)
   1.896 -fun uv_content2([]:mv_poly) = 0
   1.897 -  | uv_content2((c,e)::p1) = (gcd_int c (uv_content2(p1)));
   1.898 -
   1.899 -(*. converts a uv-polynomial from mv-representation to  uv-representation .*)
   1.900 -fun uv_to_list ([]:mv_poly)=[]:uv_poly
   1.901 -  | uv_to_list ((c1,e1)::others) = 
   1.902 -    let
   1.903 -	val count=ref 0;
   1.904 -	val max=mv_grad((c1,e1)::others); 
   1.905 -	val help=ref ((c1,e1)::others);
   1.906 -	val list=ref [];
   1.907 -    in
   1.908 -	if length(e1)>1 then raise error ("RATIONALS_TO_LIST_EXCEPTION: not univariate")
   1.909 -	else if length(e1)=0 then [c1]
   1.910 -	     else
   1.911 -		 (
   1.912 -		  count:=0;
   1.913 -		  while (!count)<=max do
   1.914 -		      (
   1.915 -		       if length(!help)>0 andalso hd(#2(hd(!help)))=max-(!count) then 
   1.916 -			   (
   1.917 -			    list:=(#1(hd(!help)))::(!list);		       
   1.918 -			    help:=tl(!help) 
   1.919 -			    )
   1.920 -		       else 
   1.921 -			   (
   1.922 -			    list:= 0::(!list)
   1.923 -			    );
   1.924 -		       count := (!count) + 1
   1.925 -		       );
   1.926 -		      (!list)
   1.927 -		      )
   1.928 -    end;
   1.929 -
   1.930 -(*. converts a uv-polynomial from uv-representation to mv-representation .*)
   1.931 -fun uv_to_poly ([]:uv_poly) = []:mv_poly
   1.932 -  | uv_to_poly p1 = 
   1.933 -    let
   1.934 -	val count=ref 0;
   1.935 -	val help=ref p1;
   1.936 -	val list=ref [];
   1.937 -    in
   1.938 -	while length(!help)>0 do
   1.939 -	    (
   1.940 -	     if hd(!help)=0 then ()
   1.941 -	     else list:=(hd(!help),[!count])::(!list);
   1.942 -	     count:=(!count)+1;
   1.943 -	     help:=tl(!help)
   1.944 -	     );
   1.945 -	    (!list)
   1.946 -    end;
   1.947 -
   1.948 -(*. univariate gcd calculation from polynomials in multivariate representation .*)
   1.949 -fun uv_gcd ([]:mv_poly) p2 = p2
   1.950 -  | uv_gcd p1 ([]:mv_poly) = p1
   1.951 -  | uv_gcd p1 [(c,[e])] = 
   1.952 -    let 
   1.953 -	val list=ref (rev(sort (mv_geq LEX_) (mv_shorten(p1,LEX_))));
   1.954 -	val min=uv_mod_min(e,(hd(#2(hd(rev(!list))))));
   1.955 -    in
   1.956 -	[(gcd_int (uv_content2(p1)) c,[min])]
   1.957 -    end
   1.958 -  | uv_gcd [(c,[e])] p2 = 
   1.959 -    let 
   1.960 -	val list=ref (rev(sort (mv_geq LEX_) (mv_shorten(p2,LEX_))));
   1.961 -	val min=uv_mod_min(e,(hd(#2(hd(rev(!list))))));
   1.962 -    in
   1.963 -	[(gcd_int (uv_content2(p2)) c,[min])]
   1.964 -    end 
   1.965 -  | uv_gcd p11 p22 = uv_to_poly(uv_mod_gcd (uv_to_list(mv_shorten(p11,LEX_))) (uv_to_list(mv_shorten(p22,LEX_))));
   1.966 -
   1.967 -(*. help function for the newton interpolation .*)
   1.968 -fun mv_newton_help ([]:mv_poly list,k:int) = []:mv_poly list
   1.969 -  | mv_newton_help (pl:mv_poly list,k) = 
   1.970 -    let
   1.971 -	val x=ref (rev(pl));
   1.972 -	val t=ref [];
   1.973 -	val y=ref [];
   1.974 -	val n=ref 1;
   1.975 -	val n1=ref[];
   1.976 -    in
   1.977 -	(
   1.978 -	 while length(!x)>1 do 
   1.979 -	     (
   1.980 -	      if length(hd(!x))>0 then n1:=mv_null2(#2(hd(hd(!x))))
   1.981 -	      else if length(hd(tl(!x)))>0 then n1:=mv_null2(#2(hd(hd(tl(!x)))))
   1.982 -		   else n1:=[]; 
   1.983 -	      t:= #1(mv_division(mv_add(hd(!x),mv_skalar_mul(hd(tl(!x)),~1),LEX_),[(k,!n1)],LEX_)); 
   1.984 -	      y:=(!t)::(!y);
   1.985 -	      x:=tl(!x)
   1.986 -	      );
   1.987 -	 (!y)
   1.988 -	 )
   1.989 -    end;
   1.990 -    
   1.991 -(*. help function for the newton interpolation .*)
   1.992 -fun mv_newton_add ([]:mv_poly list) t = []:mv_poly
   1.993 -  | mv_newton_add [x:mv_poly] t = x 
   1.994 -  | mv_newton_add (pl:mv_poly list) t = 
   1.995 -    let
   1.996 -	val expos=ref [];
   1.997 -	val pll=ref pl;
   1.998 -    in
   1.999 -	(
  1.1000 -
  1.1001 -	 while length(!pll)>0 andalso hd(!pll)=[]  do 
  1.1002 -	     ( 
  1.1003 -	      pll:=tl(!pll)
  1.1004 -	      ); 
  1.1005 -	 if length(!pll)>0 then expos:= #2(hd(hd(!pll))) else expos:=[];
  1.1006 -	 mv_add(hd(pl),
  1.1007 -		mv_mul(
  1.1008 -		       mv_add(mv_correct(mv_cut([(1,mv_null2(!expos))]),1),[(~t,mv_null2(!expos))],LEX_),
  1.1009 -		       mv_newton_add (tl(pl)) (t+1),
  1.1010 -		       LEX_
  1.1011 -		       ),
  1.1012 -		LEX_)
  1.1013 -	 )
  1.1014 -    end;
  1.1015 -
  1.1016 -(*. calculates the newton interpolation with polynomial coefficients .*)
  1.1017 -(*. step-depth is 1 and if the result is not an integerpolynomial .*)
  1.1018 -(*. this function returns [] .*)
  1.1019 -fun mv_newton ([]:(mv_poly) list) = []:mv_poly 
  1.1020 -  | mv_newton ([mp]:(mv_poly) list) = mp:mv_poly
  1.1021 -  | mv_newton pl =
  1.1022 -    let
  1.1023 -	val c=ref pl;
  1.1024 -	val c1=ref [];
  1.1025 -	val n=length(pl);
  1.1026 -	val k=ref 1;
  1.1027 -	val i=ref n;
  1.1028 -	val ppl=ref [];
  1.1029 -    in
  1.1030 -	c1:=hd(pl)::[];
  1.1031 -	c:=mv_newton_help(!c,!k);
  1.1032 -	c1:=(hd(!c))::(!c1);
  1.1033 -	while(length(!c)>1 andalso !k<n) do
  1.1034 -	    (	 
  1.1035 -	     k:=(!k)+1; 
  1.1036 -	     while  length(!c)>0 andalso hd(!c)=[] do c:=tl(!c); 	  
  1.1037 -	     if !c=[] then () else c:=mv_newton_help(!c,!k);
  1.1038 -	     ppl:= !c;
  1.1039 -	     if !c=[] then () else  c1:=(hd(!c))::(!c1)
  1.1040 -	     );
  1.1041 -	while  hd(!c1)=[] do c1:=tl(!c1);
  1.1042 -	c1:=rev(!c1);
  1.1043 -	ppl:= !c1;
  1.1044 -	mv_newton_add (!c1) 1
  1.1045 -    end;
  1.1046 -
  1.1047 -(*. sets the exponents of the first variable to zero .*)
  1.1048 -fun mv_null3([]:mv_poly)    = []:mv_poly
  1.1049 -  | mv_null3((x,y)::xs) = (x,0::tl(y))::mv_null3(xs);
  1.1050 -
  1.1051 -(*. calculates the minimum exponents of a multivariate polynomial .*)
  1.1052 -fun mv_min_pp([]:mv_poly)=[]
  1.1053 -  | mv_min_pp((c,e)::xs)=
  1.1054 -    let
  1.1055 -	val y=ref xs;
  1.1056 -	val x=ref [];
  1.1057 -    in
  1.1058 -	(
  1.1059 -	 x:=e;
  1.1060 -	 while length(!y)>0 do
  1.1061 -	     (
  1.1062 -	      x:=(map uv_mod_min) ((!x) ~~ (#2(hd(!y))));
  1.1063 -	      y:=tl(!y)
  1.1064 -	      );
  1.1065 -	 !x
  1.1066 -	 )
  1.1067 -    end;
  1.1068 -
  1.1069 -(*. checks if all elements of the list have value zero .*)
  1.1070 -fun list_is_null [] = true 
  1.1071 -  | list_is_null (x::xs) = (x=0 andalso list_is_null(xs)); 
  1.1072 -
  1.1073 -(* check if main variable is zero*)
  1.1074 -fun main_zero (ms : mv_poly) = (list_is_null o (map (hd o #2))) ms;
  1.1075 -
  1.1076 -(*. calculates the content of an polynomial .*)
  1.1077 -fun mv_content([]:mv_poly) = []:mv_poly
  1.1078 -  | mv_content(p1) = 
  1.1079 -    let
  1.1080 -	val list=ref (rev(sort (mv_geq LEX_) (mv_shorten(p1,LEX_))));
  1.1081 -	val test=ref (hd(#2(hd(!list))));
  1.1082 -	val result=ref []; 
  1.1083 -	val min=(hd(#2(hd(rev(!list)))));
  1.1084 -    in
  1.1085 -	(
  1.1086 -	 if length(!list)>1 then
  1.1087 -	     (
  1.1088 -	      while (if length(!list)>0 then (hd(#2(hd(!list)))=(!test)) else false) do
  1.1089 -		  (
  1.1090 -		   result:=(#1(hd(!list)),tl(#2(hd(!list))))::(!result);
  1.1091 -		   
  1.1092 -		   if length(!list)<1 then list:=[]
  1.1093 -		   else list:=tl(!list) 
  1.1094 -		       
  1.1095 -		       );		  
  1.1096 -		  if length(!list)>0 then  
  1.1097 -		   ( 
  1.1098 -		    list:=mv_gcd (!result) (mv_cut(mv_content(!list))) 
  1.1099 -		    ) 
  1.1100 -		  else list:=(!result); 
  1.1101 -		  list:=mv_correct(!list,0);  
  1.1102 -		  (!list) 
  1.1103 -		  )
  1.1104 -	 else
  1.1105 -	     (
  1.1106 -	      mv_null3(!list) 
  1.1107 -	      )
  1.1108 -	     )
  1.1109 -    end
  1.1110 -
  1.1111 -(*. calculates the primitiv part of a polynomial .*)
  1.1112 -and mv_pp([]:mv_poly) = []:mv_poly
  1.1113 -  | mv_pp(p1) = let
  1.1114 -		    val cont=ref []; 
  1.1115 -		    val pp=ref[];
  1.1116 -		in
  1.1117 -		    cont:=mv_content(p1);
  1.1118 -		    pp:=(#1(mv_division(p1,!cont,LEX_)));
  1.1119 -		    if !pp=[] 
  1.1120 -			then raise error("RATIONALS_MV_PP_EXCEPTION: Invalid Content ")
  1.1121 -		    else (!pp)
  1.1122 -		end
  1.1123 -
  1.1124 -(*. calculates the gcd of two multivariate polynomials with a modular approach .*)
  1.1125 -and mv_gcd ([]:mv_poly) ([]:mv_poly) :mv_poly= []:mv_poly
  1.1126 -  | mv_gcd ([]:mv_poly) (p2) :mv_poly= p2:mv_poly
  1.1127 -  | mv_gcd (p1:mv_poly) ([]) :mv_poly= p1:mv_poly
  1.1128 -  | mv_gcd ([(x,xs)]:mv_poly) ([(y,ys)]):mv_poly = 
  1.1129 -     let
  1.1130 -      val xpoly:mv_poly = [(x,xs)];
  1.1131 -      val ypoly:mv_poly = [(y,ys)];
  1.1132 -     in 
  1.1133 -	(
  1.1134 -	 if xs=ys then [((gcd_int x y),xs)]
  1.1135 -	 else [((gcd_int x y),(map uv_mod_min)(xs~~ys))]:mv_poly
  1.1136 -        )
  1.1137 -    end 
  1.1138 -  | mv_gcd (p1:mv_poly) ([(y,ys)]) :mv_poly= 
  1.1139 -	(
  1.1140 -	 [(gcd_int (uv_content2(p1)) (y),(map  uv_mod_min)(mv_min_pp(p1)~~ys))]:mv_poly
  1.1141 -	)
  1.1142 -  | mv_gcd ([(y,ys)]:mv_poly) (p2):mv_poly = 
  1.1143 -	(
  1.1144 -         [(gcd_int (uv_content2(p2)) (y),(map  uv_mod_min)(mv_min_pp(p2)~~ys))]:mv_poly
  1.1145 -        )
  1.1146 -  | mv_gcd (p1':mv_poly) (p2':mv_poly):mv_poly=
  1.1147 -    let
  1.1148 -	val vc=length(#2(hd(p1')));
  1.1149 -	val cont = 
  1.1150 -		  (
  1.1151 -                   if main_zero(mv_content(p1')) andalso 
  1.1152 -                     (main_zero(mv_content(p2'))) then
  1.1153 -                     mv_correct((mv_gcd (mv_cut(mv_content(p1'))) (mv_cut(mv_content(p2')))),0)
  1.1154 -                   else 
  1.1155 -                     mv_gcd (mv_content(p1')) (mv_content(p2'))
  1.1156 -                  );
  1.1157 -	val p1= #1(mv_division(p1',mv_content(p1'),LEX_));
  1.1158 -	val p2= #1(mv_division(p2',mv_content(p2'),LEX_)); 
  1.1159 -	val gcd=ref [];
  1.1160 -	val candidate=ref [];
  1.1161 -	val interpolation_list=ref [];
  1.1162 -	val delta=ref [];
  1.1163 -        val p1r = ref [];
  1.1164 -        val p2r = ref [];
  1.1165 -        val p1r' = ref [];
  1.1166 -        val p2r' = ref [];
  1.1167 -	val factor=ref [];
  1.1168 -	val r=ref 0;
  1.1169 -	val gcd_r=ref [];
  1.1170 -	val d=ref 0;
  1.1171 -	val exit=ref 0;
  1.1172 -	val current_degree=ref 99999; (*. FIXME: unlimited ! .*)
  1.1173 -    in
  1.1174 -	(
  1.1175 -	 if vc<2 then (* areUnivariate(p1',p2') *)
  1.1176 -	     (
  1.1177 -	      gcd:=uv_gcd (mv_shorten(p1',LEX_)) (mv_shorten(p2',LEX_))
  1.1178 -	      )
  1.1179 -	 else
  1.1180 -	     (
  1.1181 -	      while !exit=0 do
  1.1182 -		  (
  1.1183 -		   r:=(!r)+1;
  1.1184 -                   p1r := mv_lc(p1,LEX_);
  1.1185 -		   p2r := mv_lc(p2,LEX_);
  1.1186 -                   if main_zero(!p1r) andalso
  1.1187 -                      main_zero(!p2r) 
  1.1188 -                   then
  1.1189 -                       (
  1.1190 -                        delta := mv_correct((mv_gcd (mv_cut (!p1r)) (mv_cut (!p2r))),0)
  1.1191 -                       )
  1.1192 -                   else
  1.1193 -                       (
  1.1194 -		        delta := mv_gcd (!p1r) (!p2r)
  1.1195 -                       );
  1.1196 -		   (*if mv_shorten(mv_subs(!p1r,!r),LEX_)=[] andalso 
  1.1197 -		      mv_shorten(mv_subs(!p2r,!r),LEX_)=[] *)
  1.1198 -		   if mv_lc2(mv_shorten(mv_subs(!p1r,!r),LEX_),LEX_)=0 andalso 
  1.1199 -		      mv_lc2(mv_shorten(mv_subs(!p2r,!r),LEX_),LEX_)=0 
  1.1200 -                   then 
  1.1201 -                       (
  1.1202 -		       )
  1.1203 -		   else 
  1.1204 -		       (
  1.1205 -			gcd_r:=mv_shorten(mv_gcd (mv_shorten(mv_subs(p1,!r),LEX_)) 
  1.1206 -					         (mv_shorten(mv_subs(p2,!r),LEX_)) ,LEX_);
  1.1207 -			gcd_r:= #1(mv_division(mv_mul(mv_correct(mv_subs(!delta,!r),0),!gcd_r,LEX_),
  1.1208 -					       mv_correct(mv_lc(!gcd_r,LEX_),0),LEX_));
  1.1209 -			d:=mv_deg2(!gcd_r); (* deg(gcd_r,z) *)
  1.1210 -			if (!d < !current_degree) then 
  1.1211 -			    (
  1.1212 -			     current_degree:= !d;
  1.1213 -			     interpolation_list:=mv_correct(!gcd_r,0)::(!interpolation_list)
  1.1214 -			     )
  1.1215 -			else
  1.1216 -			    (
  1.1217 -			     if (!d = !current_degree) then
  1.1218 -				 (
  1.1219 -				  interpolation_list:=mv_correct(!gcd_r,0)::(!interpolation_list)
  1.1220 -				  )
  1.1221 -			     else () 
  1.1222 -				 )
  1.1223 -			    );
  1.1224 -		      if length(!interpolation_list)> uv_mod_min(mv_deg(p1),mv_deg(p2)) then 
  1.1225 -			  (
  1.1226 -			   candidate := mv_newton(rev(!interpolation_list));
  1.1227 -			   if !candidate=[] then ()
  1.1228 -			   else
  1.1229 -			       (
  1.1230 -				candidate:=mv_pp(!candidate);
  1.1231 -				if mv_divides(!candidate,p1) andalso mv_divides(!candidate,p2) then
  1.1232 -				    (
  1.1233 -				     gcd:= mv_mul(!candidate,cont,LEX_);
  1.1234 -				     exit:=1
  1.1235 -				     )
  1.1236 -				else ()
  1.1237 -				    );
  1.1238 -			       interpolation_list:=[mv_correct(!gcd_r,0)]
  1.1239 -			       )
  1.1240 -		      else ()
  1.1241 -			  )
  1.1242 -	     );
  1.1243 -	     (!gcd):mv_poly
  1.1244 -	     )
  1.1245 -    end;	
  1.1246 -
  1.1247 -
  1.1248 -(*. calculates the least common divisor of two polynomials .*)
  1.1249 -fun mv_lcm (p1:mv_poly) (p2:mv_poly) :mv_poly = 
  1.1250 -    (
  1.1251 -     #1(mv_division(mv_mul(p1,p2,LEX_),mv_gcd p1 p2,LEX_))
  1.1252 -     );
  1.1253 -
  1.1254 -(*. gets the variables (strings) of a term .*)
  1.1255 -fun get_vars(term1) = (map free2str) (vars term1); (*["a","b","c"]; *)
  1.1256 -
  1.1257 -(*. counts the negative coefficents in a polynomial .*)
  1.1258 -fun count_neg ([]:mv_poly) = 0 
  1.1259 -  | count_neg ((c,e)::xs) = if c<0 then 1+count_neg xs
  1.1260 -			  else count_neg xs;
  1.1261 -
  1.1262 -(*. help function for is_polynomial  
  1.1263 -    checks the order of the operators .*)
  1.1264 -fun test_polynomial (Const ("uminus",_) $ Free (str,_)) _ = true (*WN.13.3.03*)
  1.1265 -  | test_polynomial (t as Free(str,_)) v = true
  1.1266 -  | test_polynomial (t as Const ("op *",_) $ t1 $ t2) v = if v="^" then false
  1.1267 -						     else (test_polynomial t1 "*") andalso (test_polynomial t2 "*")
  1.1268 -  | test_polynomial (t as Const ("op +",_) $ t1 $ t2) v = if v="*" orelse v="^" then false 
  1.1269 -							  else (test_polynomial t1 " ") andalso (test_polynomial t2 " ")
  1.1270 -  | test_polynomial (t as Const ("Atools.pow",_) $ t1 $ t2) v = (test_polynomial t1 "^") andalso (test_polynomial t2 "^")
  1.1271 -  | test_polynomial _ v = false;  
  1.1272 -
  1.1273 -(*. tests if a term is a polynomial .*)  
  1.1274 -fun is_polynomial t = test_polynomial t " ";
  1.1275 -
  1.1276 -(*. help function for is_expanded 
  1.1277 -    checks the order of the operators .*)
  1.1278 -fun test_exp (t as Free(str,_)) v = true 
  1.1279 -  | test_exp (t as Const ("op *",_) $ t1 $ t2) v = if v="^" then false
  1.1280 -						     else (test_exp t1 "*") andalso (test_exp t2 "*")
  1.1281 -  | test_exp (t as Const ("op +",_) $ t1 $ t2) v = if v="*" orelse v="^" then false 
  1.1282 -							  else (test_exp t1 " ") andalso (test_exp t2 " ") 
  1.1283 -  | test_exp (t as Const ("op -",_) $ t1 $ t2) v = if v="*" orelse v="^" then false 
  1.1284 -							  else (test_exp t1 " ") andalso (test_exp t2 " ")
  1.1285 -  | test_exp (t as Const ("Atools.pow",_) $ t1 $ t2) v = (test_exp t1 "^") andalso (test_exp t2 "^")
  1.1286 -  | test_exp  _ v = false;
  1.1287 -
  1.1288 -
  1.1289 -(*. help function for check_coeff: 
  1.1290 -    converts the term to a list of coefficients .*) 
  1.1291 -fun term2coef' (t as Free(str,_(*typ*))) v :mv_poly option = 
  1.1292 -    let
  1.1293 -	val x=ref NONE;
  1.1294 -	val len=ref 0;
  1.1295 -	val vl=ref [];
  1.1296 -	val vh=ref [];
  1.1297 -	val i=ref 0;
  1.1298 -    in 
  1.1299 -	if is_numeral str then
  1.1300 -	    (
  1.1301 -	     SOME [(((the o int_of_str) str),mv_null2(v))] handle _ => NONE
  1.1302 -		 )
  1.1303 -	else (* variable *)
  1.1304 -	    (
  1.1305 -	     len:=length(v);
  1.1306 -	     vh:=v;
  1.1307 -	     while ((!len)>(!i)) do
  1.1308 -		 (
  1.1309 -		  if str=hd((!vh)) then
  1.1310 -		      (
  1.1311 -		       vl:=1::(!vl)
  1.1312 -		       )
  1.1313 -		  else 
  1.1314 -		      (
  1.1315 -		       vl:=0::(!vl)
  1.1316 -		       );
  1.1317 -		      vh:=tl(!vh);
  1.1318 -		      i:=(!i)+1    
  1.1319 -		      );		
  1.1320 -		 SOME [(1,rev(!vl))] handle _ => NONE
  1.1321 -	    )
  1.1322 -    end
  1.1323 -  | term2coef' (Const ("op *",_) $ t1 $ t2) v :mv_poly option= 
  1.1324 -    let
  1.1325 -	val t1pp=ref [];
  1.1326 -	val t2pp=ref [];
  1.1327 -	val t1c=ref 0;
  1.1328 -	val t2c=ref 0;
  1.1329 -    in
  1.1330 -	(
  1.1331 -	 t1pp:=(#2(hd(the(term2coef' t1 v))));
  1.1332 -	 t2pp:=(#2(hd(the(term2coef' t2 v))));
  1.1333 -	 t1c:=(#1(hd(the(term2coef' t1 v))));
  1.1334 -	 t2c:=(#1(hd(the(term2coef' t2 v))));
  1.1335 -	
  1.1336 -	 SOME [( (!t1c)*(!t2c) ,( (map op+) ((!t1pp)~~(!t2pp)) ) )] handle _ => NONE 
  1.1337 -		
  1.1338 -	 )
  1.1339 -    end
  1.1340 -  | term2coef' (Const ("Atools.pow",_) $ (t1 as Free (str1,_)) $ (t2 as Free (str2,_))) v :mv_poly option= 
  1.1341 -    let
  1.1342 -	val x=ref NONE;
  1.1343 -	val len=ref 0;
  1.1344 -	val vl=ref [];
  1.1345 -	val vh=ref [];
  1.1346 -	val vtemp=ref [];
  1.1347 -	val i=ref 0;	 
  1.1348 -    in
  1.1349 -    (
  1.1350 -     if (not o is_numeral) str1 andalso is_numeral str2 then
  1.1351 -	 (
  1.1352 -	  len:=length(v);
  1.1353 -	  vh:=v;
  1.1354 -
  1.1355 -	  while ((!len)>(!i)) do
  1.1356 -	      (
  1.1357 -	       if str1=hd((!vh)) then
  1.1358 -		   (
  1.1359 -		    vl:=((the o int_of_str) str2)::(!vl)
  1.1360 -		    )
  1.1361 -	       else 
  1.1362 -		   (
  1.1363 -		    vl:=0::(!vl)
  1.1364 -		    );
  1.1365 -		   vh:=tl(!vh);
  1.1366 -		   i:=(!i)+1     
  1.1367 -		   );
  1.1368 -	      SOME [(1,rev(!vl))] handle _ => NONE
  1.1369 -	      )
  1.1370 -     else raise error ("RATIONALS_TERM2COEF_EXCEPTION 1: Invalid term")
  1.1371 -	 )
  1.1372 -    end
  1.1373 -  | term2coef' (Const ("op +",_) $ t1 $ t2) v :mv_poly option= 
  1.1374 -    (
  1.1375 -     SOME ((the(term2coef' t1 v)) @ (the(term2coef' t2 v))) handle _ => NONE
  1.1376 -	 )
  1.1377 -  | term2coef' (Const ("op -",_) $ t1 $ t2) v :mv_poly option= 
  1.1378 -    (
  1.1379 -     SOME ((the(term2coef' t1 v)) @ mv_skalar_mul((the(term2coef' t2 v)),1)) handle _ => NONE
  1.1380 -	 )
  1.1381 -  | term2coef' (term) v = raise error ("RATIONALS_TERM2COEF_EXCEPTION 2: Invalid term");
  1.1382 -
  1.1383 -(*. checks if all coefficients of a polynomial are positiv (except the first) .*)
  1.1384 -fun check_coeff t = (* erste Koeffizient kann <0 sein !!! *)
  1.1385 -    if count_neg(tl(the(term2coef' t (get_vars(t)))))=0 then true 
  1.1386 -    else false;
  1.1387 -
  1.1388 -(*. checks for expanded term [3] .*)
  1.1389 -fun is_expanded t = test_exp t " " andalso check_coeff(t); 
  1.1390 -
  1.1391 -(*WN.7.3.03 Hilfsfunktion f"ur term2poly'*)
  1.1392 -fun mk_monom v' p vs = 
  1.1393 -    let fun conv p (v: string) = if v'= v then p else 0
  1.1394 -    in map (conv p) vs end;
  1.1395 -(* mk_monom "y" 5 ["a","b","x","y","z"];
  1.1396 -val it = [0,0,0,5,0] : int list*)
  1.1397 -
  1.1398 -(*. this function converts the term representation into the internal representation mv_poly .*)
  1.1399 -fun term2poly' (Const ("uminus",_) $ Free (str,_)) v = (*WN.7.3.03*)
  1.1400 -    if is_numeral str 
  1.1401 -    then SOME [((the o int_of_str) ("-"^str), mk_monom "#" 0 v)]
  1.1402 -    else SOME [(~1, mk_monom str 1 v)]
  1.1403 -
  1.1404 -  | term2poly' (Free(str,_)) v :mv_poly option = 
  1.1405 -    let
  1.1406 -	val x=ref NONE;
  1.1407 -	val len=ref 0;
  1.1408 -	val vl=ref [];
  1.1409 -	val vh=ref [];
  1.1410 -	val i=ref 0;
  1.1411 -    in 
  1.1412 -	if is_numeral str then
  1.1413 -	    (
  1.1414 -	     SOME [(((the o int_of_str) str),mv_null2 v)] handle _ => NONE
  1.1415 -		 )
  1.1416 -	else (* variable *)
  1.1417 -	    (
  1.1418 -	     len:=length v;
  1.1419 -	     vh:= v;
  1.1420 -	     while ((!len)>(!i)) do
  1.1421 -		 (
  1.1422 -		  if str=hd((!vh)) then
  1.1423 -		      (
  1.1424 -		       vl:=1::(!vl)
  1.1425 -		       )
  1.1426 -		  else 
  1.1427 -		      (
  1.1428 -		       vl:=0::(!vl)
  1.1429 -		       );
  1.1430 -		      vh:=tl(!vh);
  1.1431 -		      i:=(!i)+1    
  1.1432 -		      );		
  1.1433 -		 SOME [(1,rev(!vl))] handle _ => NONE
  1.1434 -	    )
  1.1435 -    end
  1.1436 -  | term2poly' (Const ("op *",_) $ t1 $ t2) v :mv_poly option= 
  1.1437 -    let
  1.1438 -	val t1pp=ref [];
  1.1439 -	val t2pp=ref [];
  1.1440 -	val t1c=ref 0;
  1.1441 -	val t2c=ref 0;
  1.1442 -    in
  1.1443 -	(
  1.1444 -	 t1pp:=(#2(hd(the(term2poly' t1 v))));
  1.1445 -	 t2pp:=(#2(hd(the(term2poly' t2 v))));
  1.1446 -	 t1c:=(#1(hd(the(term2poly' t1 v))));
  1.1447 -	 t2c:=(#1(hd(the(term2poly' t2 v))));
  1.1448 -	
  1.1449 -	 SOME [( (!t1c)*(!t2c) ,( (map op+) ((!t1pp)~~(!t2pp)) ) )] 
  1.1450 -	 handle _ => NONE 
  1.1451 -		
  1.1452 -	 )
  1.1453 -    end
  1.1454 -  | term2poly' (Const ("Atools.pow",_) $ (t1 as Free (str1,_)) $ 
  1.1455 -		      (t2 as Free (str2,_))) v :mv_poly option= 
  1.1456 -    let
  1.1457 -	val x=ref NONE;
  1.1458 -	val len=ref 0;
  1.1459 -	val vl=ref [];
  1.1460 -	val vh=ref [];
  1.1461 -	val vtemp=ref [];
  1.1462 -	val i=ref 0;	 
  1.1463 -    in
  1.1464 -    (
  1.1465 -     if (not o is_numeral) str1 andalso is_numeral str2 then
  1.1466 -	 (
  1.1467 -	  len:=length(v);
  1.1468 -	  vh:=v;
  1.1469 -
  1.1470 -	  while ((!len)>(!i)) do
  1.1471 -	      (
  1.1472 -	       if str1=hd((!vh)) then
  1.1473 -		   (
  1.1474 -		    vl:=((the o int_of_str) str2)::(!vl)
  1.1475 -		    )
  1.1476 -	       else 
  1.1477 -		   (
  1.1478 -		    vl:=0::(!vl)
  1.1479 -		    );
  1.1480 -		   vh:=tl(!vh);
  1.1481 -		   i:=(!i)+1     
  1.1482 -		   );
  1.1483 -	      SOME [(1,rev(!vl))] handle _ => NONE
  1.1484 -	      )
  1.1485 -     else raise error ("RATIONALS_TERM2POLY_EXCEPTION 1: Invalid term")
  1.1486 -	 )
  1.1487 -    end
  1.1488 -  | term2poly' (Const ("op +",_) $ t1 $ t2) v :mv_poly option = 
  1.1489 -    (
  1.1490 -     SOME ((the(term2poly' t1 v)) @ (the(term2poly' t2 v))) handle _ => NONE
  1.1491 -	 )
  1.1492 -  | term2poly' (Const ("op -",_) $ t1 $ t2) v :mv_poly option = 
  1.1493 -    (
  1.1494 -     SOME ((the(term2poly' t1 v)) @ mv_skalar_mul((the(term2poly' t2 v)),~1)) handle _ => NONE
  1.1495 -	 )
  1.1496 -  | term2poly' (term) v = raise error ("RATIONALS_TERM2POLY_EXCEPTION 2: Invalid term");
  1.1497 -
  1.1498 -(*. translates an Isabelle term into internal representation.
  1.1499 -    term2poly
  1.1500 -    fn : term ->              (*normalform [2]                    *)
  1.1501 -    	 string list ->       (*for ...!!! BITTE DIE ERKLÄRUNG, 
  1.1502 -    			       DIE DU MIR LETZTES MAL GEGEBEN HAST*)
  1.1503 -    	 mv_monom list        (*internal representation           *)
  1.1504 -    		  option      (*the translation may fail with NONE*)
  1.1505 -.*)
  1.1506 -fun term2poly (t:term) v = 
  1.1507 -     if is_polynomial t then term2poly' t v
  1.1508 -     else raise error ("term2poly: invalid = "^(term2str t));
  1.1509 -
  1.1510 -(*. same as term2poly with automatic detection of the variables .*)
  1.1511 -fun term2polyx t = term2poly t (((map free2str) o vars) t); 
  1.1512 -
  1.1513 -(*. checks if the term is in expanded polynomial form and converts it into the internal representation .*)
  1.1514 -fun expanded2poly (t:term) v = 
  1.1515 -    (*if is_expanded t then*) term2poly' t v
  1.1516 -    (*else raise error ("RATIONALS_EXPANDED2POLY_EXCEPTION: Invalid Polynomial")*);
  1.1517 -
  1.1518 -(*. same as expanded2poly with automatic detection of the variables .*)
  1.1519 -fun expanded2polyx t = expanded2poly t (((map free2str) o vars) t);
  1.1520 -
  1.1521 -(*. converts a powerproduct into term representation .*)
  1.1522 -fun powerproduct2term(xs,v) =  
  1.1523 -    let
  1.1524 -	val xss=ref xs;
  1.1525 -	val vv=ref v;
  1.1526 -    in
  1.1527 -	(
  1.1528 -	 while hd(!xss)=0 do 
  1.1529 -	     (
  1.1530 -	      xss:=tl(!xss);
  1.1531 -	      vv:=tl(!vv)
  1.1532 -	      );
  1.1533 -	     
  1.1534 -	 if list_is_null(tl(!xss)) then 
  1.1535 -	     (
  1.1536 -	      if hd(!xss)=1 then Free(hd(!vv), HOLogic.realT)
  1.1537 -	      else
  1.1538 -		  (
  1.1539 -		   Const("Atools.pow",[HOLogic.realT,HOLogic.realT]--->HOLogic.realT) $ 
  1.1540 -		   Free(hd(!vv), HOLogic.realT) $  Free(str_of_int (hd(!xss)),HOLogic.realT)
  1.1541 -		   )
  1.1542 -	      )
  1.1543 -	 else
  1.1544 -	     (
  1.1545 -	      if hd(!xss)=1 then 
  1.1546 -		  ( 
  1.1547 -		   Const("op *",[HOLogic.realT,HOLogic.realT]--->HOLogic.realT) $ 
  1.1548 -		   Free(hd(!vv), HOLogic.realT) $
  1.1549 -		   powerproduct2term(tl(!xss),tl(!vv))
  1.1550 -		   )
  1.1551 -	      else
  1.1552 -		  (
  1.1553 -		   Const("op *",[HOLogic.realT,HOLogic.realT]--->HOLogic.realT) $ 
  1.1554 -		   (
  1.1555 -		    Const("Atools.pow",[HOLogic.realT,HOLogic.realT]--->HOLogic.realT) $ 
  1.1556 -		    Free(hd(!vv), HOLogic.realT) $  Free(str_of_int (hd(!xss)),HOLogic.realT)
  1.1557 -		    ) $
  1.1558 -		    powerproduct2term(tl(!xss),tl(!vv))
  1.1559 -		   )
  1.1560 -	      )
  1.1561 -	 )
  1.1562 -    end;
  1.1563 -
  1.1564 -(*. converts a monom into term representation .*)
  1.1565 -(*fun monom2term ((c,e):mv_monom, v:string list) = 
  1.1566 -    if c=0 then Free(str_of_int 0,HOLogic.realT)  
  1.1567 -    else
  1.1568 -	(
  1.1569 -	 if list_is_null(e) then
  1.1570 -	     ( 
  1.1571 -	      Free(str_of_int c,HOLogic.realT)  
  1.1572 -	      )
  1.1573 -	 else
  1.1574 -	     (
  1.1575 -	      if c=1 then 
  1.1576 -		  (
  1.1577 -		   powerproduct2term(e,v)
  1.1578 -		   )
  1.1579 -	      else
  1.1580 -		  (
  1.1581 -		   Const("op *",[HOLogic.realT,HOLogic.realT]--->HOLogic.realT) $
  1.1582 -		   Free(str_of_int c,HOLogic.realT)  $
  1.1583 -		   powerproduct2term(e,v)
  1.1584 -		   )
  1.1585 -		  )
  1.1586 -	     );*)
  1.1587 -
  1.1588 -
  1.1589 -(*fun monom2term ((i, is):mv_monom, v) = 
  1.1590 -    if list_is_null is 
  1.1591 -    then 
  1.1592 -	if i >= 0 
  1.1593 -	then Free (str_of_int i, HOLogic.realT)
  1.1594 -	else Const ("uminus", HOLogic.realT --> HOLogic.realT) $
  1.1595 -		   Free ((str_of_int o abs) i, HOLogic.realT)
  1.1596 -    else
  1.1597 -	if i > 0 
  1.1598 -	then Const ("op *", [HOLogic.realT,HOLogic.realT]---> HOLogic.realT) $
  1.1599 -		   (Free (str_of_int i, HOLogic.realT)) $
  1.1600 -		   powerproduct2term(is, v)
  1.1601 -	else Const ("op *", [HOLogic.realT,HOLogic.realT]---> HOLogic.realT) $
  1.1602 -		   (Const ("uminus", HOLogic.realT --> HOLogic.realT) $
  1.1603 -		   Free ((str_of_int o abs) i, HOLogic.realT)) $
  1.1604 -		   powerproduct2term(is, vs);---------------------------*)
  1.1605 -fun monom2term ((i, is) : mv_monom, vs) = 
  1.1606 -    if list_is_null is 
  1.1607 -    then Free (str_of_int i, HOLogic.realT)
  1.1608 -    else if i = 1
  1.1609 -    then powerproduct2term (is, vs)
  1.1610 -    else Const ("op *", [HOLogic.realT, HOLogic.realT] ---> HOLogic.realT) $
  1.1611 -	       (Free (str_of_int i, HOLogic.realT)) $
  1.1612 -	       powerproduct2term (is, vs);
  1.1613 -    
  1.1614 -(*. converts the internal polynomial representation into an Isabelle term.*)
  1.1615 -fun poly2term' ([] : mv_poly, vs) = Free(str_of_int 0, HOLogic.realT)  
  1.1616 -  | poly2term' ([(c, e) : mv_monom], vs) = monom2term ((c, e), vs)
  1.1617 -  | poly2term' ((c, e) :: ces, vs) =  
  1.1618 -    Const("op +", [HOLogic.realT, HOLogic.realT] ---> HOLogic.realT) $
  1.1619 -         poly2term (ces, vs) $ monom2term ((c, e), vs)
  1.1620 -and poly2term (xs, vs) = poly2term' (rev (sort (mv_geq LEX_) (xs)), vs);
  1.1621 -
  1.1622 -
  1.1623 -(*. converts a monom into term representation .*)
  1.1624 -(*. ignores the sign of the coefficients => use only for exp-poly functions .*)
  1.1625 -fun monom2term2((c,e):mv_monom, v:string list) =  
  1.1626 -    if c=0 then Free(str_of_int 0,HOLogic.realT)  
  1.1627 -    else
  1.1628 -	(
  1.1629 -	 if list_is_null(e) then
  1.1630 -	     ( 
  1.1631 -	      Free(str_of_int (abs(c)),HOLogic.realT)  
  1.1632 -	      )
  1.1633 -	 else
  1.1634 -	     (
  1.1635 -	      if abs(c)=1 then 
  1.1636 -		  (
  1.1637 -		   powerproduct2term(e,v)
  1.1638 -		   )
  1.1639 -	      else
  1.1640 -		  (
  1.1641 -		   Const("op *",[HOLogic.realT,HOLogic.realT]--->HOLogic.realT) $
  1.1642 -		   Free(str_of_int (abs(c)),HOLogic.realT)  $
  1.1643 -		   powerproduct2term(e,v)
  1.1644 -		   )
  1.1645 -		  )
  1.1646 -	     );
  1.1647 -
  1.1648 -(*. converts the expanded polynomial representation into the term representation .*)
  1.1649 -fun exp2term' ([]:mv_poly,vars) =  Free(str_of_int 0,HOLogic.realT)  
  1.1650 -  | exp2term' ([(c,e)],vars) =     monom2term((c,e),vars) 			     
  1.1651 -  | exp2term' ((c1,e1)::others,vars) =  
  1.1652 -    if c1<0 then 	
  1.1653 -	Const("op -",[HOLogic.realT,HOLogic.realT]--->HOLogic.realT) $
  1.1654 -	exp2term'(others,vars) $
  1.1655 -	( 
  1.1656 -	 monom2term2((c1,e1),vars)
  1.1657 -	 ) 
  1.1658 -    else
  1.1659 -	Const("op +",[HOLogic.realT,HOLogic.realT]--->HOLogic.realT) $
  1.1660 -	exp2term'(others,vars) $
  1.1661 -	( 
  1.1662 -	 monom2term2((c1,e1),vars)
  1.1663 -	 );
  1.1664 -	
  1.1665 -(*. sorts the powerproduct by lexicographic termorder and converts them into 
  1.1666 -    a term in polynomial representation .*)
  1.1667 -fun poly2expanded (xs,vars) = exp2term'(rev(sort (mv_geq LEX_) (xs)),vars);
  1.1668 -
  1.1669 -(*. converts a polynomial into expanded form .*)
  1.1670 -fun polynomial2expanded t =  
  1.1671 -    (let 
  1.1672 -	val vars=(((map free2str) o vars) t);
  1.1673 -    in
  1.1674 -	SOME (poly2expanded (the (term2poly t vars), vars))
  1.1675 -    end) handle _ => NONE;
  1.1676 -
  1.1677 -(*. converts a polynomial into polynomial form .*)
  1.1678 -fun expanded2polynomial t =  
  1.1679 -    (let 
  1.1680 -	val vars=(((map free2str) o vars) t);
  1.1681 -    in
  1.1682 -	SOME (poly2term (the (expanded2poly t vars), vars))
  1.1683 -    end) handle _ => NONE;
  1.1684 -
  1.1685 -
  1.1686 -(*. calculates the greatest common divisor of numerator and denominator and seperates it from each .*)
  1.1687 -fun step_cancel (t as Const ("HOL.divide",_) $ p1 $ p2) = 
  1.1688 -    let
  1.1689 -	val p1' = ref [];
  1.1690 -	val p2' = ref [];
  1.1691 -	val p3  = ref []
  1.1692 -	val vars = rev(get_vars(p1) union get_vars(p2));
  1.1693 -    in
  1.1694 -	(
  1.1695 -         p1':= sort (mv_geq LEX_) (the (term2poly p1 vars ));
  1.1696 -       	 p2':= sort (mv_geq LEX_) (the (term2poly p2 vars ));
  1.1697 -	 p3:= sort (mv_geq LEX_) (mv_gcd (!p1') (!p2'));
  1.1698 -	 if (!p3)=[(1,mv_null2(vars))] then 
  1.1699 -	     (
  1.1700 -	      Const ("HOL.divide",[HOLogic.realT,HOLogic.realT]--->HOLogic.realT) $ p1 $ p2
  1.1701 -	      )
  1.1702 -	 else
  1.1703 -	     (
  1.1704 -
  1.1705 -	      p1':=sort (mv_geq LEX_) (#1(mv_division((!p1'),(!p3),LEX_)));
  1.1706 -	      p2':=sort (mv_geq LEX_) (#1(mv_division((!p2'),(!p3),LEX_)));
  1.1707 -	      
  1.1708 -	      if #1(hd(sort (mv_geq LEX_) (!p2'))) (*mv_lc2(!p2',LEX_)*)>0 then
  1.1709 -	      (
  1.1710 -	       Const ("HOL.divide",[HOLogic.realT,HOLogic.realT]--->HOLogic.realT) 
  1.1711 -	       $ 
  1.1712 -	       (
  1.1713 -		Const ("op *",[HOLogic.realT,HOLogic.realT]--->HOLogic.realT) $ 
  1.1714 -		poly2term(!p1',vars) $ 
  1.1715 -		poly2term(!p3,vars) 
  1.1716 -		) 
  1.1717 -	       $ 
  1.1718 -	       (
  1.1719 -		Const ("op *",[HOLogic.realT,HOLogic.realT]--->HOLogic.realT) $ 
  1.1720 -		poly2term(!p2',vars) $ 
  1.1721 -		poly2term(!p3,vars)
  1.1722 -		) 	
  1.1723 -	       )	
  1.1724 -	      else
  1.1725 -	      (
  1.1726 -	       p1':=mv_skalar_mul(!p1',~1);
  1.1727 -	       p2':=mv_skalar_mul(!p2',~1);
  1.1728 -	       p3:=mv_skalar_mul(!p3,~1);
  1.1729 -	       (
  1.1730 -		Const ("HOL.divide",[HOLogic.realT,HOLogic.realT]--->HOLogic.realT) 
  1.1731 -		$ 
  1.1732 -		(
  1.1733 -		 Const ("op *",[HOLogic.realT,HOLogic.realT]--->HOLogic.realT) $ 
  1.1734 -		 poly2term(!p1',vars) $ 
  1.1735 -		 poly2term(!p3,vars) 
  1.1736 -		 ) 
  1.1737 -		$ 
  1.1738 -		(
  1.1739 -		 Const ("op *",[HOLogic.realT,HOLogic.realT]--->HOLogic.realT) $ 
  1.1740 -		 poly2term(!p2',vars) $ 
  1.1741 -		 poly2term(!p3,vars)
  1.1742 -		 ) 	
  1.1743 -		)	
  1.1744 -	       )	  
  1.1745 -	      )
  1.1746 -	     )
  1.1747 -    end
  1.1748 -| step_cancel _ = raise error ("RATIONALS_STEP_CANCEL_EXCEPTION: Invalid fraction"); 
  1.1749 -
  1.1750 -
  1.1751 -(*. same as step_cancel, this time for expanded forms (input+output) .*)
  1.1752 -fun step_cancel_expanded (t as Const ("HOL.divide",_) $ p1 $ p2) = 
  1.1753 -    let
  1.1754 -	val p1' = ref [];
  1.1755 -	val p2' = ref [];
  1.1756 -	val p3  = ref []
  1.1757 -	val vars = rev(get_vars(p1) union get_vars(p2));
  1.1758 -    in
  1.1759 -	(
  1.1760 -         p1':= sort (mv_geq LEX_) (the (expanded2poly p1 vars ));
  1.1761 -       	 p2':= sort (mv_geq LEX_) (the (expanded2poly p2 vars ));
  1.1762 -	 p3:= sort (mv_geq LEX_) (mv_gcd (!p1') (!p2'));
  1.1763 -	 if (!p3)=[(1,mv_null2(vars))] then 
  1.1764 -	     (
  1.1765 -	      Const ("HOL.divide",[HOLogic.realT,HOLogic.realT]--->HOLogic.realT) $ p1 $ p2
  1.1766 -	      )
  1.1767 -	 else
  1.1768 -	     (
  1.1769 -
  1.1770 -	      p1':=sort (mv_geq LEX_) (#1(mv_division((!p1'),(!p3),LEX_)));
  1.1771 -	      p2':=sort (mv_geq LEX_) (#1(mv_division((!p2'),(!p3),LEX_)));
  1.1772 -	      
  1.1773 -	      if #1(hd(sort (mv_geq LEX_) (!p2')))(* mv_lc2(!p2',LEX_)*)>0 then
  1.1774 -	      (
  1.1775 -	       Const ("HOL.divide",[HOLogic.realT,HOLogic.realT]--->HOLogic.realT) 
  1.1776 -	       $ 
  1.1777 -	       (
  1.1778 -		Const ("op *",[HOLogic.realT,HOLogic.realT]--->HOLogic.realT) $ 
  1.1779 -		poly2expanded(!p1',vars) $ 
  1.1780 -		poly2expanded(!p3,vars) 
  1.1781 -		) 
  1.1782 -	       $ 
  1.1783 -	       (
  1.1784 -		Const ("op *",[HOLogic.realT,HOLogic.realT]--->HOLogic.realT) $ 
  1.1785 -		poly2expanded(!p2',vars) $ 
  1.1786 -		poly2expanded(!p3,vars)
  1.1787 -		) 	
  1.1788 -	       )	
  1.1789 -	      else
  1.1790 -	      (
  1.1791 -	       p1':=mv_skalar_mul(!p1',~1);
  1.1792 -	       p2':=mv_skalar_mul(!p2',~1);
  1.1793 -	       p3:=mv_skalar_mul(!p3,~1);
  1.1794 -	       (
  1.1795 -		Const ("HOL.divide",[HOLogic.realT,HOLogic.realT]--->HOLogic.realT) 
  1.1796 -		$ 
  1.1797 -		(
  1.1798 -		 Const ("op *",[HOLogic.realT,HOLogic.realT]--->HOLogic.realT) $ 
  1.1799 -		 poly2expanded(!p1',vars) $ 
  1.1800 -		 poly2expanded(!p3,vars) 
  1.1801 -		 ) 
  1.1802 -		$ 
  1.1803 -		(
  1.1804 -		 Const ("op *",[HOLogic.realT,HOLogic.realT]--->HOLogic.realT) $ 
  1.1805 -		 poly2expanded(!p2',vars) $ 
  1.1806 -		 poly2expanded(!p3,vars)
  1.1807 -		 ) 	
  1.1808 -		)	
  1.1809 -	       )	  
  1.1810 -	      )
  1.1811 -	     )
  1.1812 -    end
  1.1813 -| step_cancel_expanded _ = raise error ("RATIONALS_STEP_CANCEL_EXCEPTION: Invalid fraction"); 
  1.1814 -
  1.1815 -(*. calculates the greatest common divisor of numerator and denominator and divides each through it .*)
  1.1816 -fun direct_cancel (t as Const ("HOL.divide",_) $ p1 $ p2) = 
  1.1817 -    let
  1.1818 -	val p1' = ref [];
  1.1819 -	val p2' = ref [];
  1.1820 -	val p3  = ref []
  1.1821 -	val vars = rev(get_vars(p1) union get_vars(p2));
  1.1822 -    in
  1.1823 -	(
  1.1824 -	 p1':=sort (mv_geq LEX_) (mv_shorten((the (term2poly p1 vars )),LEX_));
  1.1825 -	 p2':=sort (mv_geq LEX_) (mv_shorten((the (term2poly p2 vars )),LEX_));	 
  1.1826 -	 p3 :=sort (mv_geq LEX_) (mv_gcd (!p1') (!p2'));
  1.1827 -
  1.1828 -	 if (!p3)=[(1,mv_null2(vars))] then 
  1.1829 -	     (
  1.1830 -	      (Const ("HOL.divide",[HOLogic.realT,HOLogic.realT]--->HOLogic.realT) $ p1 $ p2,[])
  1.1831 -	      )
  1.1832 -	 else
  1.1833 -	     (
  1.1834 -	      p1':=sort (mv_geq LEX_) (#1(mv_division((!p1'),(!p3),LEX_)));
  1.1835 -	      p2':=sort (mv_geq LEX_) (#1(mv_division((!p2'),(!p3),LEX_)));
  1.1836 -	      if #1(hd(sort (mv_geq LEX_) (!p2'))) (*mv_lc2(!p2',LEX_)*)>0 then	      
  1.1837 -	      (
  1.1838 -	       (
  1.1839 -		Const ("HOL.divide",[HOLogic.realT,HOLogic.realT]--->HOLogic.realT) 
  1.1840 -		$ 
  1.1841 -		(
  1.1842 -		 poly2term((!p1'),vars)
  1.1843 -		 ) 
  1.1844 -		$ 
  1.1845 -		( 
  1.1846 -		 poly2term((!p2'),vars)
  1.1847 -		 ) 	
  1.1848 -		)
  1.1849 -	       ,
  1.1850 -	       if mv_grad(!p3)>0 then 
  1.1851 -		   [
  1.1852 -		    (
  1.1853 -		     Const ("Not",[bool]--->bool) $
  1.1854 -		     (
  1.1855 -		      Const("op =",[HOLogic.realT,HOLogic.realT]--->bool) $
  1.1856 -		      poly2term((!p3),vars) $
  1.1857 -		      Free("0",HOLogic.realT)
  1.1858 -		      )
  1.1859 -		     )
  1.1860 -		    ]
  1.1861 -	       else
  1.1862 -		   []
  1.1863 -		   )
  1.1864 -	      else
  1.1865 -		  (
  1.1866 -		   p1':=mv_skalar_mul(!p1',~1);
  1.1867 -		   p2':=mv_skalar_mul(!p2',~1);
  1.1868 -		   if length(!p3)> 2*(count_neg(!p3)) then () else p3 :=mv_skalar_mul(!p3,~1); 
  1.1869 -		       (
  1.1870 -			Const ("HOL.divide",[HOLogic.realT,HOLogic.realT]--->HOLogic.realT) 
  1.1871 -			$ 
  1.1872 -			(
  1.1873 -			 poly2term((!p1'),vars)
  1.1874 -			 ) 
  1.1875 -			$ 
  1.1876 -			( 
  1.1877 -			 poly2term((!p2'),vars)
  1.1878 -			 ) 	
  1.1879 -			,
  1.1880 -			if mv_grad(!p3)>0 then 
  1.1881 -			    [
  1.1882 -			     (
  1.1883 -			      Const ("Not",[bool]--->bool) $
  1.1884 -			      (
  1.1885 -			       Const("op =",[HOLogic.realT,HOLogic.realT]--->bool) $
  1.1886 -			       poly2term((!p3),vars) $
  1.1887 -			       Free("0",HOLogic.realT)
  1.1888 -			       )
  1.1889 -			      )
  1.1890 -			     ]
  1.1891 -			else
  1.1892 -			    []
  1.1893 -			    )
  1.1894 -		       )
  1.1895 -		  )
  1.1896 -	     )
  1.1897 -    end
  1.1898 -  | direct_cancel _ = raise error ("RATIONALS_DIRECT_CANCEL_EXCEPTION: Invalid fraction"); 
  1.1899 -
  1.1900 -(*. same es direct_cancel, this time for expanded forms (input+output).*) 
  1.1901 -fun direct_cancel_expanded (t as Const ("HOL.divide",_) $ p1 $ p2) =  
  1.1902 -    let
  1.1903 -	val p1' = ref [];
  1.1904 -	val p2' = ref [];
  1.1905 -	val p3  = ref []
  1.1906 -	val vars = rev(get_vars(p1) union get_vars(p2));
  1.1907 -    in
  1.1908 -	(
  1.1909 -	 p1':=sort (mv_geq LEX_) (mv_shorten((the (expanded2poly p1 vars )),LEX_));
  1.1910 -	 p2':=sort (mv_geq LEX_) (mv_shorten((the (expanded2poly p2 vars )),LEX_));	 
  1.1911 -	 p3 :=sort (mv_geq LEX_) (mv_gcd (!p1') (!p2'));
  1.1912 -
  1.1913 -	 if (!p3)=[(1,mv_null2(vars))] then 
  1.1914 -	     (
  1.1915 -	      (Const ("HOL.divide",[HOLogic.realT,HOLogic.realT]--->HOLogic.realT) $ p1 $ p2,[])
  1.1916 -	      )
  1.1917 -	 else
  1.1918 -	     (
  1.1919 -	      p1':=sort (mv_geq LEX_) (#1(mv_division((!p1'),(!p3),LEX_)));
  1.1920 -	      p2':=sort (mv_geq LEX_) (#1(mv_division((!p2'),(!p3),LEX_)));
  1.1921 -	      if #1(hd(sort (mv_geq LEX_) (!p2'))) (*mv_lc2(!p2',LEX_)*)>0 then	      
  1.1922 -	      (
  1.1923 -	       (
  1.1924 -		Const ("HOL.divide",[HOLogic.realT,HOLogic.realT]--->HOLogic.realT) 
  1.1925 -		$ 
  1.1926 -		(
  1.1927 -		 poly2expanded((!p1'),vars)
  1.1928 -		 ) 
  1.1929 -		$ 
  1.1930 -		( 
  1.1931 -		 poly2expanded((!p2'),vars)
  1.1932 -		 ) 	
  1.1933 -		)
  1.1934 -	       ,
  1.1935 -	       if mv_grad(!p3)>0 then 
  1.1936 -		   [
  1.1937 -		    (
  1.1938 -		     Const ("Not",[bool]--->bool) $
  1.1939 -		     (
  1.1940 -		      Const("op =",[HOLogic.realT,HOLogic.realT]--->bool) $
  1.1941 -		      poly2expanded((!p3),vars) $
  1.1942 -		      Free("0",HOLogic.realT)
  1.1943 -		      )
  1.1944 -		     )
  1.1945 -		    ]
  1.1946 -	       else
  1.1947 -		   []
  1.1948 -		   )
  1.1949 -	      else
  1.1950 -		  (
  1.1951 -		   p1':=mv_skalar_mul(!p1',~1);
  1.1952 -		   p2':=mv_skalar_mul(!p2',~1);
  1.1953 -		   if length(!p3)> 2*(count_neg(!p3)) then () else p3 :=mv_skalar_mul(!p3,~1); 
  1.1954 -		       (
  1.1955 -			Const ("HOL.divide",[HOLogic.realT,HOLogic.realT]--->HOLogic.realT) 
  1.1956 -			$ 
  1.1957 -			(
  1.1958 -			 poly2expanded((!p1'),vars)
  1.1959 -			 ) 
  1.1960 -			$ 
  1.1961 -			( 
  1.1962 -			 poly2expanded((!p2'),vars)
  1.1963 -			 ) 	
  1.1964 -			,
  1.1965 -			if mv_grad(!p3)>0 then 
  1.1966 -			    [
  1.1967 -			     (
  1.1968 -			      Const ("Not",[bool]--->bool) $
  1.1969 -			      (
  1.1970 -			       Const("op =",[HOLogic.realT,HOLogic.realT]--->bool) $
  1.1971 -			       poly2expanded((!p3),vars) $
  1.1972 -			       Free("0",HOLogic.realT)
  1.1973 -			       )
  1.1974 -			      )
  1.1975 -			     ]
  1.1976 -			else
  1.1977 -			    []
  1.1978 -			    )
  1.1979 -		       )
  1.1980 -		  )
  1.1981 -	     )
  1.1982 -    end
  1.1983 -  | direct_cancel_expanded _ = raise error ("RATIONALS_DIRECT_CANCEL_EXCEPTION: Invalid fraction"); 
  1.1984 -
  1.1985 -
  1.1986 -(*. adds two fractions .*)
  1.1987 -fun add_fract ((Const("HOL.divide",_) $ t11 $ t12),(Const("HOL.divide",_) $ t21 $ t22)) =
  1.1988 -    let
  1.1989 -	val vars=get_vars(t11) union get_vars(t12) union get_vars(t21) union get_vars(t22);
  1.1990 -	val t11'=ref (the(term2poly t11 vars));
  1.1991 -val _= writeln"### add_fract: done t11"
  1.1992 -	val t12'=ref (the(term2poly t12 vars));
  1.1993 -val _= writeln"### add_fract: done t12"
  1.1994 -	val t21'=ref (the(term2poly t21 vars));
  1.1995 -val _= writeln"### add_fract: done t21"
  1.1996 -	val t22'=ref (the(term2poly t22 vars));
  1.1997 -val _= writeln"### add_fract: done t22"
  1.1998 -	val den=ref [];
  1.1999 -	val nom=ref [];
  1.2000 -	val m1=ref [];
  1.2001 -	val m2=ref [];
  1.2002 -    in
  1.2003 -	
  1.2004 -	(
  1.2005 -	 den :=sort (mv_geq LEX_) (mv_lcm (!t12') (!t22'));
  1.2006 -writeln"### add_fract: done sort mv_lcm";
  1.2007 -	 m1  :=sort (mv_geq LEX_) (#1(mv_division(!den,!t12',LEX_)));
  1.2008 -writeln"### add_fract: done sort mv_division t12";
  1.2009 -	 m2  :=sort (mv_geq LEX_) (#1(mv_division(!den,!t22',LEX_)));
  1.2010 -writeln"### add_fract: done sort mv_division t22";
  1.2011 -	 nom :=sort (mv_geq LEX_) 
  1.2012 -		    (mv_shorten(mv_add(mv_mul(!t11',!m1,LEX_),
  1.2013 -				       mv_mul(!t21',!m2,LEX_),
  1.2014 -				       LEX_),
  1.2015 -				LEX_));
  1.2016 -writeln"### add_fract: done sort mv_add";
  1.2017 -	 (
  1.2018 -	  Const ("HOL.divide",[HOLogic.realT,HOLogic.realT]--->HOLogic.realT) 
  1.2019 -	  $ 
  1.2020 -	  (
  1.2021 -	   poly2term((!nom),vars)
  1.2022 -	   ) 
  1.2023 -	  $ 
  1.2024 -	  ( 
  1.2025 -	   poly2term((!den),vars)
  1.2026 -	   )	      
  1.2027 -	  )
  1.2028 -	 )	     
  1.2029 -    end 
  1.2030 -  | add_fract (_,_) = raise error ("RATIONALS_ADD_FRACTION_EXCEPTION: Invalid add_fraction call");
  1.2031 -
  1.2032 -(*. adds two expanded fractions .*)
  1.2033 -fun add_fract_exp ((Const("HOL.divide",_) $ t11 $ t12),(Const("HOL.divide",_) $ t21 $ t22)) =
  1.2034 -    let
  1.2035 -	val vars=get_vars(t11) union get_vars(t12) union get_vars(t21) union get_vars(t22);
  1.2036 -	val t11'=ref (the(expanded2poly t11 vars));
  1.2037 -	val t12'=ref (the(expanded2poly t12 vars));
  1.2038 -	val t21'=ref (the(expanded2poly t21 vars));
  1.2039 -	val t22'=ref (the(expanded2poly t22 vars));
  1.2040 -	val den=ref [];
  1.2041 -	val nom=ref [];
  1.2042 -	val m1=ref [];
  1.2043 -	val m2=ref [];
  1.2044 -    in
  1.2045 -	
  1.2046 -	(
  1.2047 -	 den :=sort (mv_geq LEX_) (mv_lcm (!t12') (!t22'));
  1.2048 -	 m1  :=sort (mv_geq LEX_) (#1(mv_division(!den,!t12',LEX_)));
  1.2049 -	 m2  :=sort (mv_geq LEX_) (#1(mv_division(!den,!t22',LEX_)));
  1.2050 -	 nom :=sort (mv_geq LEX_) (mv_shorten(mv_add(mv_mul(!t11',!m1,LEX_),mv_mul(!t21',!m2,LEX_),LEX_),LEX_));
  1.2051 -	 (
  1.2052 -	  Const ("HOL.divide",[HOLogic.realT,HOLogic.realT]--->HOLogic.realT) 
  1.2053 -	  $ 
  1.2054 -	  (
  1.2055 -	   poly2expanded((!nom),vars)
  1.2056 -	   ) 
  1.2057 -	  $ 
  1.2058 -	  ( 
  1.2059 -	   poly2expanded((!den),vars)
  1.2060 -	   )	      
  1.2061 -	  )
  1.2062 -	 )	     
  1.2063 -    end 
  1.2064 -  | add_fract_exp (_,_) = raise error ("RATIONALS_ADD_FRACTION_EXP_EXCEPTION: Invalid add_fraction call");
  1.2065 -
  1.2066 -(*. adds a list of terms .*)
  1.2067 -fun add_list_of_fractions []= (Free("0",HOLogic.realT),[])
  1.2068 -  | add_list_of_fractions [x]= direct_cancel x
  1.2069 -  | add_list_of_fractions (x::y::xs) = 
  1.2070 -    let
  1.2071 -	val (t1a,rest1)=direct_cancel(x);
  1.2072 -val _= writeln"### add_list_of_fractions xs: has done direct_cancel(x)";
  1.2073 -	val (t2a,rest2)=direct_cancel(y);
  1.2074 -val _= writeln"### add_list_of_fractions xs: has done direct_cancel(y)";
  1.2075 -	val (t3a,rest3)=(add_list_of_fractions (add_fract(t1a,t2a)::xs));
  1.2076 -val _= writeln"### add_list_of_fractions xs: has done add_list_of_fraction xs";
  1.2077 -	val (t4a,rest4)=direct_cancel(t3a);
  1.2078 -val _= writeln"### add_list_of_fractions xs: has done direct_cancel(t3a)";
  1.2079 -	val rest=rest1 union rest2 union rest3 union rest4;
  1.2080 -    in
  1.2081 -	(writeln"### add_list_of_fractions in";
  1.2082 -	 (
  1.2083 -	 (t4a,rest) 
  1.2084 -	 )
  1.2085 -	 )
  1.2086 -    end;
  1.2087 -
  1.2088 -(*. adds a list of expanded terms .*)
  1.2089 -fun add_list_of_fractions_exp []= (Free("0",HOLogic.realT),[])
  1.2090 -  | add_list_of_fractions_exp [x]= direct_cancel_expanded x
  1.2091 -  | add_list_of_fractions_exp (x::y::xs) = 
  1.2092 -    let
  1.2093 -	val (t1a,rest1)=direct_cancel_expanded(x);
  1.2094 -	val (t2a,rest2)=direct_cancel_expanded(y);
  1.2095 -	val (t3a,rest3)=(add_list_of_fractions_exp (add_fract_exp(t1a,t2a)::xs));
  1.2096 -	val (t4a,rest4)=direct_cancel_expanded(t3a);
  1.2097 -	val rest=rest1 union rest2 union rest3 union rest4;
  1.2098 -    in
  1.2099 -	(
  1.2100 -	 (t4a,rest) 
  1.2101 -	 )
  1.2102 -    end;
  1.2103 -
  1.2104 -(*. calculates the lcm of a list of mv_poly .*)
  1.2105 -fun calc_lcm ([x],var)= (x,var) 
  1.2106 -  | calc_lcm ((x::xs),var) = (mv_lcm x (#1(calc_lcm (xs,var))),var);
  1.2107 -
  1.2108 -(*. converts a list of terms to a list of mv_poly .*)
  1.2109 -fun t2d([],_)=[] 
  1.2110 -  | t2d((t as (Const("HOL.divide",_) $ p1 $ p2))::xs,vars)= (the(term2poly p2 vars)) :: t2d(xs,vars); 
  1.2111 -
  1.2112 -(*. same as t2d, this time for expanded forms .*)
  1.2113 -fun t2d_exp([],_)=[]  
  1.2114 -  | t2d_exp((t as (Const("HOL.divide",_) $ p1 $ p2))::xs,vars)= (the(expanded2poly p2 vars)) :: t2d_exp(xs,vars);
  1.2115 -
  1.2116 -(*. converts a list of fract terms to a list of their denominators .*)
  1.2117 -fun termlist2denominators [] = ([],[])
  1.2118 -  | termlist2denominators xs = 
  1.2119 -    let	
  1.2120 -	val xxs=ref xs;
  1.2121 -	val var=ref [];
  1.2122 -    in
  1.2123 -	var:=[];
  1.2124 -	while length(!xxs)>0 do
  1.2125 -	    (
  1.2126 -	     let 
  1.2127 -		 val (t as Const ("HOL.divide",_) $ p1x $ p2x)=hd(!xxs);
  1.2128 -	     in
  1.2129 -		 (
  1.2130 -		  xxs:=tl(!xxs);
  1.2131 -		  var:=((get_vars(p2x)) union (get_vars(p1x)) union (!var))
  1.2132 -		  )
  1.2133 -	     end
  1.2134 -	     );
  1.2135 -	    (t2d(xs,!var),!var)
  1.2136 -    end;
  1.2137 -
  1.2138 -(*. calculates the lcm of a list of mv_poly .*)
  1.2139 -fun calc_lcm ([x],var)= (x,var) 
  1.2140 -  | calc_lcm ((x::xs),var) = (mv_lcm x (#1(calc_lcm (xs,var))),var);
  1.2141 -
  1.2142 -(*. converts a list of terms to a list of mv_poly .*)
  1.2143 -fun t2d([],_)=[] 
  1.2144 -  | t2d((t as (Const("HOL.divide",_) $ p1 $ p2))::xs,vars)= (the(term2poly p2 vars)) :: t2d(xs,vars); 
  1.2145 -
  1.2146 -(*. same as t2d, this time for expanded forms .*)
  1.2147 -fun t2d_exp([],_)=[]  
  1.2148 -  | t2d_exp((t as (Const("HOL.divide",_) $ p1 $ p2))::xs,vars)= (the(expanded2poly p2 vars)) :: t2d_exp(xs,vars);
  1.2149 -
  1.2150 -(*. converts a list of fract terms to a list of their denominators .*)
  1.2151 -fun termlist2denominators [] = ([],[])
  1.2152 -  | termlist2denominators xs = 
  1.2153 -    let	
  1.2154 -	val xxs=ref xs;
  1.2155 -	val var=ref [];
  1.2156 -    in
  1.2157 -	var:=[];
  1.2158 -	while length(!xxs)>0 do
  1.2159 -	    (
  1.2160 -	     let 
  1.2161 -		 val (t as Const ("HOL.divide",_) $ p1x $ p2x)=hd(!xxs);
  1.2162 -	     in
  1.2163 -		 (
  1.2164 -		  xxs:=tl(!xxs);
  1.2165 -		  var:=((get_vars(p2x)) union (get_vars(p1x)) union (!var))
  1.2166 -		  )
  1.2167 -	     end
  1.2168 -	     );
  1.2169 -	    (t2d(xs,!var),!var)
  1.2170 -    end;
  1.2171 -
  1.2172 -(*. same as termlist2denminators, this time for expanded forms .*)
  1.2173 -fun termlist2denominators_exp [] = ([],[])
  1.2174 -  | termlist2denominators_exp xs = 
  1.2175 -    let	
  1.2176 -	val xxs=ref xs;
  1.2177 -	val var=ref [];
  1.2178 -    in
  1.2179 -	var:=[];
  1.2180 -	while length(!xxs)>0 do
  1.2181 -	    (
  1.2182 -	     let 
  1.2183 -		 val (t as Const ("HOL.divide",_) $ p1x $ p2x)=hd(!xxs);
  1.2184 -	     in
  1.2185 -		 (
  1.2186 -		  xxs:=tl(!xxs);
  1.2187 -		  var:=((get_vars(p2x)) union (get_vars(p1x)) union (!var))
  1.2188 -		  )
  1.2189 -	     end
  1.2190 -	     );
  1.2191 -	    (t2d_exp(xs,!var),!var)
  1.2192 -    end;
  1.2193 -
  1.2194 -(*. reduces all fractions to the least common denominator .*)
  1.2195 -fun com_den(x::xs,denom,den,var)=
  1.2196 -    let 
  1.2197 -	val (t as Const ("HOL.divide",_) $ p1' $ p2')=x;
  1.2198 -	val p2= sort (mv_geq LEX_) (the(term2poly p2' var));
  1.2199 -	val p3= #1(mv_division(denom,p2,LEX_));
  1.2200 -	val p1var=get_vars(p1');
  1.2201 -    in     
  1.2202 -	if length(xs)>0 then 
  1.2203 -	    if p3=[(1,mv_null2(var))] then
  1.2204 -		(
  1.2205 -		 Const ("op +",[HOLogic.realT,HOLogic.realT]--->HOLogic.realT)
  1.2206 -		 $ 
  1.2207 -		 (
  1.2208 -		  Const ("HOL.divide",[HOLogic.realT,HOLogic.realT]--->HOLogic.realT) 
  1.2209 -		  $ 
  1.2210 -		  poly2term(the (term2poly p1' p1var),p1var)
  1.2211 -		  $ 
  1.2212 -		  den	
  1.2213 -		  )    
  1.2214 -		 $ 
  1.2215 -		 #1(com_den(xs,denom,den,var))
  1.2216 -		,
  1.2217 -		[]
  1.2218 -		)
  1.2219 -	    else
  1.2220 -		(
  1.2221 -		 Const ("op +",[HOLogic.realT,HOLogic.realT]--->HOLogic.realT) 
  1.2222 -		 $ 
  1.2223 -		 (
  1.2224 -		  Const ("HOL.divide",[HOLogic.realT,HOLogic.realT]--->HOLogic.realT) 
  1.2225 -		  $ 
  1.2226 -		  (
  1.2227 -		   Const ("op *",[HOLogic.realT,HOLogic.realT]--->HOLogic.realT) $ 
  1.2228 -		   poly2term(the (term2poly p1' p1var),p1var) $ 
  1.2229 -		   poly2term(p3,var)
  1.2230 -		   ) 
  1.2231 -		  $ 
  1.2232 -		  (
  1.2233 -		   den
  1.2234 -		   ) 	
  1.2235 -		  )
  1.2236 -		 $ 
  1.2237 -		 #1(com_den(xs,denom,den,var))
  1.2238 -		,
  1.2239 -		[]
  1.2240 -		)
  1.2241 -	else
  1.2242 -	    if p3=[(1,mv_null2(var))] then
  1.2243 -		(
  1.2244 -		 (
  1.2245 -		  Const ("HOL.divide",[HOLogic.realT,HOLogic.realT]--->HOLogic.realT) 
  1.2246 -		  $ 
  1.2247 -		  poly2term(the (term2poly p1' p1var),p1var)
  1.2248 -		  $ 
  1.2249 -		  den	
  1.2250 -		  )
  1.2251 -		 ,
  1.2252 -		 []
  1.2253 -		 )
  1.2254 -	     else
  1.2255 -		 (
  1.2256 -		  Const ("HOL.divide",[HOLogic.realT,HOLogic.realT]--->HOLogic.realT) 
  1.2257 -		  $ 
  1.2258 -		  (
  1.2259 -		   Const ("op *",[HOLogic.realT,HOLogic.realT]--->HOLogic.realT) $ 
  1.2260 -		   poly2term(the (term2poly p1' p1var),p1var) $ 
  1.2261 -		   poly2term(p3,var)
  1.2262 -		   ) 
  1.2263 -		  $ 
  1.2264 -		  den 	
  1.2265 -		  ,
  1.2266 -		  []
  1.2267 -		  )
  1.2268 -    end;
  1.2269 -
  1.2270 -(*. same as com_den, this time for expanded forms .*)
  1.2271 -fun com_den_exp(x::xs,denom,den,var)=
  1.2272 -    let 
  1.2273 -	val (t as Const ("HOL.divide",_) $ p1' $ p2')=x;
  1.2274 -	val p2= sort (mv_geq LEX_) (the(expanded2poly p2' var));
  1.2275 -	val p3= #1(mv_division(denom,p2,LEX_));
  1.2276 -	val p1var=get_vars(p1');
  1.2277 -    in     
  1.2278 -	if length(xs)>0 then 
  1.2279 -	    if p3=[(1,mv_null2(var))] then
  1.2280 -		(
  1.2281 -		 Const ("op +",[HOLogic.realT,HOLogic.realT]--->HOLogic.realT)
  1.2282 -		 $ 
  1.2283 -		 (
  1.2284 -		  Const ("HOL.divide",[HOLogic.realT,HOLogic.realT]--->HOLogic.realT) 
  1.2285 -		  $ 
  1.2286 -		  poly2expanded(the(expanded2poly p1' p1var),p1var)
  1.2287 -		  $ 
  1.2288 -		  den	
  1.2289 -		  )    
  1.2290 -		 $ 
  1.2291 -		 #1(com_den_exp(xs,denom,den,var))
  1.2292 -		,
  1.2293 -		[]
  1.2294 -		)
  1.2295 -	    else
  1.2296 -		(
  1.2297 -		 Const ("op +",[HOLogic.realT,HOLogic.realT]--->HOLogic.realT) 
  1.2298 -		 $ 
  1.2299 -		 (
  1.2300 -		  Const ("HOL.divide",[HOLogic.realT,HOLogic.realT]--->HOLogic.realT) 
  1.2301 -		  $ 
  1.2302 -		  (
  1.2303 -		   Const ("op *",[HOLogic.realT,HOLogic.realT]--->HOLogic.realT) $ 
  1.2304 -		   poly2expanded(the(expanded2poly p1' p1var),p1var) $ 
  1.2305 -		   poly2expanded(p3,var)
  1.2306 -		   ) 
  1.2307 -		  $ 
  1.2308 -		  (
  1.2309 -		   den
  1.2310 -		   ) 	
  1.2311 -		  )
  1.2312 -		 $ 
  1.2313 -		 #1(com_den_exp(xs,denom,den,var))
  1.2314 -		,
  1.2315 -		[]
  1.2316 -		)
  1.2317 -	else
  1.2318 -	    if p3=[(1,mv_null2(var))] then
  1.2319 -		(
  1.2320 -		 (
  1.2321 -		  Const ("HOL.divide",[HOLogic.realT,HOLogic.realT]--->HOLogic.realT) 
  1.2322 -		  $ 
  1.2323 -		  poly2expanded(the(expanded2poly p1' p1var),p1var)
  1.2324 -		  $ 
  1.2325 -		  den	
  1.2326 -		  )
  1.2327 -		 ,
  1.2328 -		 []
  1.2329 -		 )
  1.2330 -	     else
  1.2331 -		 (
  1.2332 -		  Const ("HOL.divide",[HOLogic.realT,HOLogic.realT]--->HOLogic.realT) 
  1.2333 -		  $ 
  1.2334 -		  (
  1.2335 -		   Const ("op *",[HOLogic.realT,HOLogic.realT]--->HOLogic.realT) $ 
  1.2336 -		   poly2expanded(the(expanded2poly p1' p1var),p1var) $ 
  1.2337 -		   poly2expanded(p3,var)
  1.2338 -		   ) 
  1.2339 -		  $ 
  1.2340 -		  den 	
  1.2341 -		  ,
  1.2342 -		  []
  1.2343 -		  )
  1.2344 -    end;
  1.2345 -
  1.2346 -(* wird aktuell nicht mehr gebraucht, bei rückänderung schon 
  1.2347 --------------------------------------------------------------
  1.2348 -(* WN0210???SK brauch ma des überhaupt *)
  1.2349 -fun com_den2(x::xs,denom,den,var)=
  1.2350 -    let 
  1.2351 -	val (t as Const ("HOL.divide",_) $ p1' $ p2')=x;
  1.2352 -	val p2= sort (mv_geq LEX_) (the(term2poly p2' var));
  1.2353 -	val p3= #1(mv_division(denom,p2,LEX_));
  1.2354 -	val p1var=get_vars(p1');
  1.2355 -    in     
  1.2356 -	if length(xs)>0 then 
  1.2357 -	    if p3=[(1,mv_null2(var))] then
  1.2358 -		(
  1.2359 -		 Const ("op +",[HOLogic.realT,HOLogic.realT]--->HOLogic.realT) $ 
  1.2360 -		 poly2term(the(term2poly p1' p1var),p1var) $ 
  1.2361 -		 com_den2(xs,denom,den,var)
  1.2362 -		)
  1.2363 -	    else
  1.2364 -		(
  1.2365 -		 Const ("op +",[HOLogic.realT,HOLogic.realT]--->HOLogic.realT) $ 
  1.2366 -		 (
  1.2367 -		   let 
  1.2368 -		       val p3'=poly2term(p3,var);
  1.2369 -		       val vars= (((map free2str) o vars) p1') union (((map free2str) o vars) p3');
  1.2370 -		   in
  1.2371 -		       poly2term(sort (mv_geq LEX_) (mv_mul(the(term2poly p1' vars) ,the(term2poly p3' vars),LEX_)),vars)
  1.2372 -		   end
  1.2373 -		  ) $ 
  1.2374 -		 com_den2(xs,denom,den,var)
  1.2375 -		)
  1.2376 -	else
  1.2377 -	    if p3=[(1,mv_null2(var))] then
  1.2378 -		(
  1.2379 -		 poly2term(the(term2poly p1' p1var),p1var)
  1.2380 -		 )
  1.2381 -	     else
  1.2382 -		 (
  1.2383 -		   let 
  1.2384 -		       val p3'=poly2term(p3,var);
  1.2385 -		       val vars= (((map free2str) o vars) p1') union (((map free2str) o vars) p3');
  1.2386 -		   in
  1.2387 -		       poly2term(sort (mv_geq LEX_) (mv_mul(the(term2poly p1' vars) ,the(term2poly p3' vars),LEX_)),vars)
  1.2388 -		   end
  1.2389 -		  )
  1.2390 -    end;
  1.2391 -
  1.2392 -(* WN0210???SK brauch ma des überhaupt *)
  1.2393 -fun com_den_exp2(x::xs,denom,den,var)=
  1.2394 -    let 
  1.2395 -	val (t as Const ("HOL.divide",_) $ p1' $ p2')=x;
  1.2396 -	val p2= sort (mv_geq LEX_) (the(expanded2poly p2' var));
  1.2397 -	val p3= #1(mv_division(denom,p2,LEX_));
  1.2398 -	val p1var=get_vars p1';
  1.2399 -    in     
  1.2400 -	if length(xs)>0 then 
  1.2401 -	    if p3=[(1,mv_null2(var))] then
  1.2402 -		(
  1.2403 -		 Const ("op +",[HOLogic.realT,HOLogic.realT]--->HOLogic.realT) $ 
  1.2404 -		 poly2expanded(the (expanded2poly p1' p1var),p1var) $ 
  1.2405 -		 com_den_exp2(xs,denom,den,var)
  1.2406 -		)
  1.2407 -	    else
  1.2408 -		(
  1.2409 -		 Const ("op +",[HOLogic.realT,HOLogic.realT]--->HOLogic.realT) $ 
  1.2410 -		 (
  1.2411 -		   let 
  1.2412 -		       val p3'=poly2expanded(p3,var);
  1.2413 -		       val vars= (((map free2str) o vars) p1') union (((map free2str) o vars) p3');
  1.2414 -		   in
  1.2415 -		       poly2expanded(sort (mv_geq LEX_) (mv_mul(the(expanded2poly p1' vars) ,the(expanded2poly p3' vars),LEX_)),vars)
  1.2416 -		   end
  1.2417 -		  ) $ 
  1.2418 -		 com_den_exp2(xs,denom,den,var)
  1.2419 -		)
  1.2420 -	else
  1.2421 -	    if p3=[(1,mv_null2(var))] then
  1.2422 -		(
  1.2423 -		 poly2expanded(the (expanded2poly p1' p1var),p1var)
  1.2424 -		 )
  1.2425 -	     else
  1.2426 -		 (
  1.2427 -		   let 
  1.2428 -		       val p3'=poly2expanded(p3,var);
  1.2429 -		       val vars= (((map free2str) o vars) p1') union (((map free2str) o vars) p3');
  1.2430 -		   in
  1.2431 -		       poly2expanded(sort (mv_geq LEX_) (mv_mul(the(expanded2poly p1' vars) ,the(expanded2poly p3' vars),LEX_)),vars)
  1.2432 -		   end
  1.2433 -		  )
  1.2434 -    end;
  1.2435 ----------------------------------------------------------*)
  1.2436 -
  1.2437 -
  1.2438 -(*. searches for an element y of a list ys, which has an gcd not 1 with x .*) 
  1.2439 -fun exists_gcd (x,[]) = false 
  1.2440 -  | exists_gcd (x,y::ys) = if mv_gcd x y = [(1,mv_null2(#2(hd(x))))] then  exists_gcd (x,ys)
  1.2441 -			   else true;
  1.2442 -
  1.2443 -(*. divides each element of the list xs with y .*)
  1.2444 -fun list_div ([],y) = [] 
  1.2445 -  | list_div (x::xs,y) = 
  1.2446 -    let
  1.2447 -	val (d,r)=mv_division(x,y,LEX_);
  1.2448 -    in
  1.2449 -	if r=[] then 
  1.2450 -	    d::list_div(xs,y)
  1.2451 -	else x::list_div(xs,y)
  1.2452 -    end;
  1.2453 -    
  1.2454 -(*. checks if x is in the list ys .*)
  1.2455 -fun in_list (x,[]) = false 
  1.2456 -  | in_list (x,y::ys) = if x=y then true
  1.2457 -			else in_list(x,ys);
  1.2458 -
  1.2459 -(*. deletes all equal elements of the list xs .*)
  1.2460 -fun kill_equal [] = [] 
  1.2461 -  | kill_equal (x::xs) = if in_list(x,xs) orelse x=[(1,mv_null2(#2(hd(x))))] then kill_equal(xs)
  1.2462 -			 else x::kill_equal(xs);
  1.2463 -
  1.2464 -(*. searches for new factors .*)
  1.2465 -fun new_factors [] = []
  1.2466 -  | new_factors (list:mv_poly list):mv_poly list = 
  1.2467 -    let
  1.2468 -	val l = kill_equal list;
  1.2469 -	val len = length(l);
  1.2470 -    in
  1.2471 -	if len>=2 then
  1.2472 -	    (
  1.2473 -	     let
  1.2474 -		 val x::y::xs=l;
  1.2475 -		 val gcd=mv_gcd x y;
  1.2476 -	     in
  1.2477 -		 if gcd=[(1,mv_null2(#2(hd(x))))] then 
  1.2478 -		     ( 
  1.2479 -		      if exists_gcd(x,xs) then new_factors (y::xs @ [x])
  1.2480 -		      else x::new_factors(y::xs)
  1.2481 -	             )
  1.2482 -		 else gcd::new_factors(kill_equal(list_div(x::y::xs,gcd)))
  1.2483 -	     end
  1.2484 -	     )
  1.2485 -	else
  1.2486 -	    if len=1 then [hd(l)]
  1.2487 -	    else []
  1.2488 -    end;
  1.2489 -
  1.2490 -(*. gets the factors of a list .*)
  1.2491 -fun get_factors x = new_factors x; 
  1.2492 -
  1.2493 -(*. multiplies the elements of the list .*)
  1.2494 -fun multi_list [] = []
  1.2495 -  | multi_list (x::xs) = if xs=[] then x
  1.2496 -			 else mv_mul(x,multi_list xs,LEX_);
  1.2497 -
  1.2498 -(*. makes a term out of the elements of the list (polynomial representation) .*)
  1.2499 -fun make_term ([],vars) = Free(str_of_int 0,HOLogic.realT) 
  1.2500 -  | make_term ((x::xs),vars) = if length(xs)=0 then poly2term(sort (mv_geq LEX_) (x),vars)
  1.2501 -			       else
  1.2502 -				   (
  1.2503 -				    Const ("op *",[HOLogic.realT,HOLogic.realT]--->HOLogic.realT) $ 
  1.2504 -				    poly2term(sort (mv_geq LEX_) (x),vars) $ 
  1.2505 -				    make_term(xs,vars)
  1.2506 -				    );
  1.2507 -
  1.2508 -(*. factorizes the denominator (polynomial representation) .*)				
  1.2509 -fun factorize_den (l,den,vars) = 
  1.2510 -    let
  1.2511 -	val factor_list=kill_equal( (get_factors l));
  1.2512 -	val mlist=multi_list(factor_list);
  1.2513 -	val (last,rest)=mv_division(den,multi_list(factor_list),LEX_);
  1.2514 -    in
  1.2515 -	if rest=[] then
  1.2516 -	    (
  1.2517 -	     if last=[(1,mv_null2(vars))] then make_term(factor_list,vars)
  1.2518 -	     else make_term(last::factor_list,vars)
  1.2519 -	     )
  1.2520 -	else raise error ("RATIONALS_FACTORIZE_DEN_EXCEPTION: Invalid factor by division")
  1.2521 -    end; 
  1.2522 -
  1.2523 -(*. makes a term out of the elements of the list (expanded polynomial representation) .*)
  1.2524 -fun make_exp ([],vars) = Free(str_of_int 0,HOLogic.realT) 
  1.2525 -  | make_exp ((x::xs),vars) = if length(xs)=0 then poly2expanded(sort (mv_geq LEX_) (x),vars)
  1.2526 -			       else
  1.2527 -				   (
  1.2528 -				    Const ("op *",[HOLogic.realT,HOLogic.realT]--->HOLogic.realT) $ 
  1.2529 -				    poly2expanded(sort (mv_geq LEX_) (x),vars) $ 
  1.2530 -				    make_exp(xs,vars)
  1.2531 -				    );
  1.2532 -
  1.2533 -(*. factorizes the denominator (expanded polynomial representation) .*)	
  1.2534 -fun factorize_den_exp (l,den,vars) = 
  1.2535 -    let
  1.2536 -	val factor_list=kill_equal( (get_factors l));
  1.2537 -	val mlist=multi_list(factor_list);
  1.2538 -	val (last,rest)=mv_division(den,multi_list(factor_list),LEX_);
  1.2539 -    in
  1.2540 -	if rest=[] then
  1.2541 -	    (
  1.2542 -	     if last=[(1,mv_null2(vars))] then make_exp(factor_list,vars)
  1.2543 -	     else make_exp(last::factor_list,vars)
  1.2544 -	     )
  1.2545 -	else raise error ("RATIONALS_FACTORIZE_DEN_EXP_EXCEPTION: Invalid factor by division")
  1.2546 -    end; 
  1.2547 -
  1.2548 -(*. calculates the common denominator of all elements of the list and multiplies .*)
  1.2549 -(*. the nominators and denominators with the correct factor .*)
  1.2550 -(*. (polynomial representation) .*)
  1.2551 -fun step_add_list_of_fractions []=(Free("0",HOLogic.realT),[]:term list)
  1.2552 -  | step_add_list_of_fractions [x]= raise error ("RATIONALS_STEP_ADD_LIST_OF_FRACTIONS_EXCEPTION: Nothing to add")
  1.2553 -  | step_add_list_of_fractions (xs) = 
  1.2554 -    let
  1.2555 -        val den_list=termlist2denominators (xs); (* list of denominators *)
  1.2556 -	val (denom,var)=calc_lcm(den_list);      (* common denominator *)
  1.2557 -	val den=factorize_den(#1(den_list),denom,var); (* faktorisierter Nenner !!! *)
  1.2558 -    in
  1.2559 -	com_den(xs,denom,den,var)
  1.2560 -    end;
  1.2561 -
  1.2562 -(*. calculates the common denominator of all elements of the list and multiplies .*)
  1.2563 -(*. the nominators and denominators with the correct factor .*)
  1.2564 -(*. (expanded polynomial representation) .*)
  1.2565 -fun step_add_list_of_fractions_exp []  = (Free("0",HOLogic.realT),[]:term list)
  1.2566 -  | step_add_list_of_fractions_exp [x] = raise error ("RATIONALS_STEP_ADD_LIST_OF_FRACTIONS_EXP_EXCEPTION: Nothing to add")
  1.2567 -  | step_add_list_of_fractions_exp (xs)= 
  1.2568 -    let
  1.2569 -        val den_list=termlist2denominators_exp (xs); (* list of denominators *)
  1.2570 -	val (denom,var)=calc_lcm(den_list);      (* common denominator *)
  1.2571 -	val den=factorize_den_exp(#1(den_list),denom,var); (* faktorisierter Nenner !!! *)
  1.2572 -    in
  1.2573 -	com_den_exp(xs,denom,den,var)
  1.2574 -    end;
  1.2575 -
  1.2576 -(* wird aktuell nicht mehr gebraucht, bei rückänderung schon 
  1.2577 --------------------------------------------------------------
  1.2578 -(* WN0210???SK brauch ma des überhaupt *)
  1.2579 -fun step_add_list_of_fractions2 []=(Free("0",HOLogic.realT),[]:term list)
  1.2580 -  | step_add_list_of_fractions2 [x]=(x,[])
  1.2581 -  | step_add_list_of_fractions2 (xs) = 
  1.2582 -    let
  1.2583 -        val den_list=termlist2denominators (xs); (* list of denominators *)
  1.2584 -	val (denom,var)=calc_lcm(den_list);      (* common denominator *)
  1.2585 -	val den=factorize_den(#1(den_list),denom,var);  (* faktorisierter Nenner !!! *)
  1.2586 -    in
  1.2587 -	(
  1.2588 -	 Const ("HOL.divide",[HOLogic.realT,HOLogic.realT]--->HOLogic.realT) $ 
  1.2589 -	 com_den2(xs,denom, poly2term(denom,var)(*den*),var) $
  1.2590 -	 poly2term(denom,var)
  1.2591 -	,
  1.2592 -	[]
  1.2593 -	)
  1.2594 -    end;
  1.2595 -
  1.2596 -(* WN0210???SK brauch ma des überhaupt *)
  1.2597 -fun step_add_list_of_fractions2_exp []=(Free("0",HOLogic.realT),[]:term list)
  1.2598 -  | step_add_list_of_fractions2_exp [x]=(x,[])
  1.2599 -  | step_add_list_of_fractions2_exp (xs) = 
  1.2600 -    let
  1.2601 -        val den_list=termlist2denominators_exp (xs); (* list of denominators *)
  1.2602 -	val (denom,var)=calc_lcm(den_list);      (* common denominator *)
  1.2603 -	val den=factorize_den_exp(#1(den_list),denom,var);  (* faktorisierter Nenner !!! *)
  1.2604 -    in
  1.2605 -	(
  1.2606 -	 Const ("HOL.divide",[HOLogic.realT,HOLogic.realT]--->HOLogic.realT) $ 
  1.2607 -	 com_den_exp2(xs,denom, poly2term(denom,var)(*den*),var) $
  1.2608 -	 poly2expanded(denom,var)
  1.2609 -	,
  1.2610 -	[]
  1.2611 -	)
  1.2612 -    end;
  1.2613 ----------------------------------------------- *)
  1.2614 -
  1.2615 -
  1.2616 -(*. converts a term, which contains severel terms seperated by +, into a list of these terms .*)
  1.2617 -fun term2list (t as (Const("HOL.divide",_) $ _ $ _)) = [t]
  1.2618 -  | term2list (t as (Const("Atools.pow",_) $ _ $ _)) = 
  1.2619 -    [Const("HOL.divide",[HOLogic.realT,HOLogic.realT]--->HOLogic.realT) $ 
  1.2620 -	  t $ Free("1",HOLogic.realT)
  1.2621 -     ]
  1.2622 -  | term2list (t as (Free(_,_))) = 
  1.2623 -    [Const("HOL.divide",[HOLogic.realT,HOLogic.realT]--->HOLogic.realT) $ 
  1.2624 -	  t $  Free("1",HOLogic.realT)
  1.2625 -     ]
  1.2626 -  | term2list (t as (Const("op *",_) $ _ $ _)) = 
  1.2627 -    [Const("HOL.divide",[HOLogic.realT,HOLogic.realT]--->HOLogic.realT) $ 
  1.2628 -	  t $ Free("1",HOLogic.realT)
  1.2629 -     ]
  1.2630 -  | term2list (Const("op +",_) $ t1 $ t2) = term2list(t1) @ term2list(t2)
  1.2631 -  | term2list (Const("op -",_) $ t1 $ t2) = 
  1.2632 -    raise error ("RATIONALS_TERM2LIST_EXCEPTION: - not implemented yet")
  1.2633 -  | term2list _ = raise error ("RATIONALS_TERM2LIST_EXCEPTION: invalid term");
  1.2634 -
  1.2635 -(*.factors out the gcd of nominator and denominator:
  1.2636 -   a/b = (a' * gcd)/(b' * gcd),  a,b,gcd  are poly[2].*)
  1.2637 -fun factout_p_  (thy:theory) t = SOME (step_cancel t,[]:term list); 
  1.2638 -fun factout_ (thy:theory) t = SOME (step_cancel_expanded t,[]:term list); 
  1.2639 -
  1.2640 -(*.cancels a single fraction with normalform [2]
  1.2641 -   resulting in a canceled fraction [2], see factout_ .*)
  1.2642 -fun cancel_p_ (thy:theory) t = (*WN.2.6.03 no rewrite -> NONE !*)
  1.2643 -    (let val (t',asm) = direct_cancel(*_expanded ... corrected MG.21.8.03*) t
  1.2644 -     in if t = t' then NONE else SOME (t',asm) 
  1.2645 -     end) handle _ => NONE;
  1.2646 -(*.the same as above with normalform [3]
  1.2647 -  val cancel_ :
  1.2648 -      theory ->        (*10.02 unused                                    *)
  1.2649 -      term -> 	       (*fraction in normalform [3]                      *)
  1.2650 -      (term * 	       (*fraction in normalform [3]                      *)
  1.2651 -       term list)      (*casual asumptions in normalform [3]             *)
  1.2652 -	  option       (*NONE: the function is not applicable            *).*)
  1.2653 -fun cancel_ (thy:theory) t = SOME (direct_cancel_expanded t) handle _ => NONE;
  1.2654 -
  1.2655 -(*.transforms sums of at least 2 fractions [3] to
  1.2656 -   sums with the least common multiple as nominator.*)
  1.2657 -fun common_nominator_p_ (thy:theory) t =
  1.2658 -((*writeln("### common_nominator_p_ called");*)
  1.2659 -    SOME (step_add_list_of_fractions(term2list(t))) handle _ => NONE
  1.2660 -);
  1.2661 -fun common_nominator_ (thy:theory) t =
  1.2662 -    SOME (step_add_list_of_fractions_exp(term2list(t))) handle _ => NONE;
  1.2663 -
  1.2664 -(*.add 2 or more fractions
  1.2665 -val add_fraction_p_ :
  1.2666 -      theory ->        (*10.02 unused                                    *)
  1.2667 -      term -> 	       (*2 or more fractions with normalform [2]         *)
  1.2668 -      (term * 	       (*one fraction with normalform [2]                *)
  1.2669 -       term list)      (*casual assumptions in normalform [2] WN0210???SK  *)
  1.2670 -	  option       (*NONE: the function is not applicable            *).*)
  1.2671 -fun add_fraction_p_ (thy:theory) t = 
  1.2672 -(writeln("### add_fraction_p_ called");
  1.2673 -    (let val ts = term2list t
  1.2674 -     in if 1 < length ts
  1.2675 -	then SOME (add_list_of_fractions ts)
  1.2676 -	else NONE (*raise error ("RATIONALS_ADD_EXCEPTION: nothing to add")*)
  1.2677 -     end) handle _ => NONE
  1.2678 -);
  1.2679 -(*.same as add_fraction_p_ but with normalform [3].*)
  1.2680 -(*SOME (step_add_list_of_fractions2(term2list(t))); *)
  1.2681 -fun add_fraction_ (thy:theory) t = 
  1.2682 -    if length(term2list(t))>1 
  1.2683 -    then SOME (add_list_of_fractions_exp(term2list(t))) handle _ => NONE
  1.2684 -    else (*raise error ("RATIONALS_ADD_FRACTION_EXCEPTION: nothing to add")*)
  1.2685 -	NONE;
  1.2686 -fun add_fraction_ (thy:theory) t = 
  1.2687 -    (if 1 < length (term2list t)
  1.2688 -     then SOME (add_list_of_fractions_exp (term2list t))
  1.2689 -     else (*raise error ("RATIONALS_ADD_FRACTION_EXCEPTION: nothing to add")*)
  1.2690 -	 NONE) handle _ => NONE;
  1.2691 -
  1.2692 -(*SOME (step_add_list_of_fractions2_exp(term2list(t))); *)
  1.2693 -
  1.2694 -(*. brings the term into a normal form .*)
  1.2695 -fun norm_rational_ (thy:theory) t = 
  1.2696 -    SOME (add_list_of_fractions(term2list(t))) handle _ => NONE; 
  1.2697 -fun norm_expanded_rat_ (thy:theory) t = 
  1.2698 -    SOME (add_list_of_fractions_exp(term2list(t))) handle _ => NONE; 
  1.2699 -
  1.2700 -
  1.2701 -(*.evaluates conditions in calculate_Rational.*)
  1.2702 -(*make local with FIXX@ME result:term *term list*)
  1.2703 -val calc_rat_erls = prep_rls(
  1.2704 -  Rls {id = "calc_rat_erls", preconds = [], rew_ord = ("dummy_ord",dummy_ord), 
  1.2705 -	 erls = e_rls, srls = Erls, calc = [], (*asm_thm = [], *)
  1.2706 -	 rules = 
  1.2707 -	 [Calc ("op =",eval_equal "#equal_"),
  1.2708 -	  Calc ("Atools.is'_const",eval_const "#is_const_"),
  1.2709 -	  Thm ("not_true",num_str not_true),
  1.2710 -	  Thm ("not_false",num_str not_false)
  1.2711 -	  ], 
  1.2712 -	 scr = EmptyScr});
  1.2713 -
  1.2714 -
  1.2715 -(*.simplifies expressions with numerals;
  1.2716 -   does NOT rearrange the term by AC-rewriting; thus terms with variables 
  1.2717 -   need to have constants to be commuted together respectively.*)
  1.2718 -val calculate_Rational = prep_rls(
  1.2719 -    merge_rls "calculate_Rational"
  1.2720 -	(Rls {id = "divide", preconds = [], rew_ord = ("dummy_ord",dummy_ord), 
  1.2721 -	      erls = calc_rat_erls, srls = Erls, (*asm_thm = [],*) 
  1.2722 -	      calc = [], 
  1.2723 -	      rules = 
  1.2724 -	      [Calc ("HOL.divide"  ,eval_cancel "#divide_"),
  1.2725 -	       
  1.2726 -	       Thm ("sym_real_minus_divide_eq",
  1.2727 -		    num_str (real_minus_divide_eq RS sym)),
  1.2728 -	       (*SYM - ?x / ?y = - (?x / ?y)  may come from subst*)
  1.2729 -	       
  1.2730 -	       Thm ("rat_add",num_str rat_add),
  1.2731 -	       (*"[| a is_const; b is_const; c is_const; d is_const |] ==> \
  1.2732 -		 \"a / c + b / d = (a * d) / (c * d) + (b * c ) / (d * c)"*)
  1.2733 -	       Thm ("rat_add1",num_str rat_add1),
  1.2734 -	       (*"[| a is_const; b is_const; c is_const |] ==> \
  1.2735 -		 \"a / c + b / c = (a + b) / c"*)
  1.2736 -	       Thm ("rat_add2",num_str rat_add2),
  1.2737 -	       (*"[| ?a is_const; ?b is_const; ?c is_const |] ==> \
  1.2738 -		 \?a / ?c + ?b = (?a + ?b * ?c) / ?c"*)
  1.2739 -	       Thm ("rat_add3",num_str rat_add3),
  1.2740 -	       (*"[| a is_const; b is_const; c is_const |] ==> \
  1.2741 -		 \"a + b / c = (a * c) / c + b / c"\
  1.2742 -		 \.... is_const to be omitted here FIXME*)
  1.2743 -	       
  1.2744 -	       Thm ("rat_mult",num_str rat_mult),
  1.2745 -	       (*a / b * (c / d) = a * c / (b * d)*)
  1.2746 -	       Thm ("real_times_divide1_eq",num_str real_times_divide1_eq),
  1.2747 -	       (*?x * (?y / ?z) = ?x * ?y / ?z*)
  1.2748 -	       Thm ("real_times_divide2_eq",num_str real_times_divide2_eq),
  1.2749 -	       (*?y / ?z * ?x = ?y * ?x / ?z*)
  1.2750 -	       
  1.2751 -	       Thm ("real_divide_divide1",num_str real_divide_divide1),
  1.2752 -	       (*"?y ~= 0 ==> ?u / ?v / (?y / ?z) = ?u / ?v * (?z / ?y)"*)
  1.2753 -	       Thm ("real_divide_divide2_eq",num_str real_divide_divide2_eq),
  1.2754 -	       (*"?x / ?y / ?z = ?x / (?y * ?z)"*)
  1.2755 -	       
  1.2756 -	       Thm ("rat_power", num_str rat_power),
  1.2757 -	       (*"(?a / ?b) ^^^ ?n = ?a ^^^ ?n / ?b ^^^ ?n"*)
  1.2758 -	       
  1.2759 -	       Thm ("mult_cross",num_str mult_cross),
  1.2760 -	       (*"[| b ~= 0; d ~= 0 |] ==> (a / b = c / d) = (a * d = b * c)*)
  1.2761 -	       Thm ("mult_cross1",num_str mult_cross1),
  1.2762 -	       (*"   b ~= 0            ==> (a / b = c    ) = (a     = b * c)*)
  1.2763 -	       Thm ("mult_cross2",num_str mult_cross2)
  1.2764 -	       (*"           d ~= 0    ==> (a     = c / d) = (a * d =     c)*)
  1.2765 -	       ], scr = EmptyScr})
  1.2766 -	calculate_Poly);
  1.2767 -
  1.2768 -
  1.2769 -(*("is_expanded", ("Rational.is'_expanded", eval_is_expanded ""))*)
  1.2770 -fun eval_is_expanded (thmid:string) _ 
  1.2771 -		       (t as (Const("Rational.is'_expanded", _) $ arg)) thy = 
  1.2772 -    if is_expanded arg
  1.2773 -    then SOME (mk_thmid thmid "" 
  1.2774 -			((Syntax.string_of_term (thy2ctxt thy)) arg) "", 
  1.2775 -	       Trueprop $ (mk_equality (t, HOLogic.true_const)))
  1.2776 -    else SOME (mk_thmid thmid "" 
  1.2777 -			((Syntax.string_of_term (thy2ctxt thy)) arg) "", 
  1.2778 -	       Trueprop $ (mk_equality (t, HOLogic.false_const)))
  1.2779 -  | eval_is_expanded _ _ _ _ = NONE; 
  1.2780 -
  1.2781 -val rational_erls = 
  1.2782 -    merge_rls "rational_erls" calculate_Rational 
  1.2783 -	      (append_rls "is_expanded" Atools_erls 
  1.2784 -			  [Calc ("Rational.is'_expanded", eval_is_expanded "")
  1.2785 -			   ]);
  1.2786 -
  1.2787 -
  1.2788 -
  1.2789 -(*.3 'reverse-rewrite-sets' for symbolic computation on rationals:
  1.2790 - =================================================================
  1.2791 - A[2] 'cancel_p': .
  1.2792 - A[3] 'cancel': .
  1.2793 - B[2] 'common_nominator_p': transforms summands in a term [2]
  1.2794 -         to fractions with the (least) common multiple as nominator.
  1.2795 - B[3] 'norm_rational': normalizes arbitrary algebraic terms (without 
  1.2796 -         radicals and transzendental functions) to one canceled fraction,
  1.2797 -	 nominator and denominator in polynomial form.
  1.2798 -
  1.2799 -In order to meet isac's requirements for interactive and stepwise calculation,
  1.2800 -each 'reverse-rewerite-set' consists of an initialization for the interpreter 
  1.2801 -state and of 4 functions, each of which employs rewriting as much as possible.
  1.2802 -The signature of these functions are the same in each 'reverse-rewrite-set' 
  1.2803 -respectively.*)
  1.2804 -
  1.2805 -(* ************************************************************************* *)
  1.2806 -
  1.2807 -
  1.2808 -local(*. cancel_p
  1.2809 -------------------------
  1.2810 -cancels a single fraction consisting of two (uni- or multivariate)
  1.2811 -polynomials WN0609???SK[2] into another such a fraction; examples:
  1.2812 -
  1.2813 -	   a^2 + -1*b^2         a + b
  1.2814 -        -------------------- = ---------
  1.2815 -	a^2 + -2*a*b + b^2     a + -1*b
  1.2816 -
  1.2817 -        a^2    a
  1.2818 -        --- = ---
  1.2819 -         a     1
  1.2820 -
  1.2821 -Remark: the reverse ruleset does _NOT_ work properly with other input !.*)
  1.2822 -(*WN020824 wir werden "uberlegen, wie wir ungeeignete inputs zur"uckweisen*)
  1.2823 -
  1.2824 -val {rules, rew_ord=(_,ro),...} =
  1.2825 -    rep_rls (assoc_rls "make_polynomial");
  1.2826 -(*WN060829 ... make_deriv does not terminate with 1st expl above,
  1.2827 -           see rational.sml --- investigate rulesets for cancel_p ---*)
  1.2828 -val {rules, rew_ord=(_,ro),...} =
  1.2829 -    rep_rls (assoc_rls "rev_rew_p");
  1.2830 -
  1.2831 -val thy = Rational.thy;
  1.2832 -
  1.2833 -(*.init_state = fn : term -> istate
  1.2834 -initialzies the state of the script interpreter. The state is:
  1.2835 -
  1.2836 -type rrlsstate =      (*state for reverse rewriting*)
  1.2837 -     (term *          (*the current formula*)
  1.2838 -      term *          (*the final term*)
  1.2839 -      rule list       (*'reverse rule list' (#)*)
  1.2840 -	    list *    (*may be serveral, eg. in norm_rational*)
  1.2841 -      (rule *         (*Thm (+ Thm generated from Calc) resulting in ...*)
  1.2842 -       (term *        (*... rewrite with ...*)
  1.2843 -	term list))   (*... assumptions*)
  1.2844 -	  list);      (*derivation from given term to normalform
  1.2845 -		       in reverse order with sym_thm;
  1.2846 -                       (#) could be extracted from here by (map #1)*).*)
  1.2847 -(* val {rules, rew_ord=(_,ro),...} =
  1.2848 -       rep_rls (assoc_rls "rev_rew_p")        (*USE ALWAYS, SEE val cancel_p*);
  1.2849 -   val (thy, eval_rls, ro) =(Rational.thy, Atools_erls, ro) (*..val cancel_p*);
  1.2850 -   val t = t;
  1.2851 -   *)
  1.2852 -fun init_state thy eval_rls ro t =
  1.2853 -    let val SOME (t',_) = factout_p_ thy t
  1.2854 -        val SOME (t'',asm) = cancel_p_ thy t
  1.2855 -        val der = reverse_deriv thy eval_rls rules ro NONE t'
  1.2856 -        val der = der @ [(Thm ("real_mult_div_cancel2",
  1.2857 -			       num_str real_mult_div_cancel2),
  1.2858 -			  (t'',asm))]
  1.2859 -        val rs = (distinct_Thm o (map #1)) der
  1.2860 -	val rs = filter_out (eq_Thms ["sym_real_add_zero_left",
  1.2861 -				      "sym_real_mult_0",
  1.2862 -				      "sym_real_mult_1"
  1.2863 -				      (*..insufficient,eg.make_Polynomial*)])rs
  1.2864 -    in (t,t'',[rs(*here only _ONE_ to ease locate_rule*)],der) end;
  1.2865 -
  1.2866 -(*.locate_rule = fn : rule list -> term -> rule
  1.2867 -		      -> (rule * (term * term list) option) list.
  1.2868 -  checks a rule R for being a cancel-rule, and if it is,
  1.2869 -  then return the list of rules (+ the terms they are rewriting to)
  1.2870 -  which need to be applied before R should be applied.
  1.2871 -  precondition: the rule is applicable to the argument-term.
  1.2872 -arguments:
  1.2873 -  rule list: the reverse rule list
  1.2874 -  -> term  : ... to which the rule shall be applied
  1.2875 -  -> rule  : ... to be applied to term
  1.2876 -value:
  1.2877 -  -> (rule           : a rule rewriting to ...
  1.2878 -      * (term        : ... the resulting term ...
  1.2879 -         * term list): ... with the assumptions ( //#0).
  1.2880 -      ) list         : there may be several such rules;
  1.2881 -		       the list is empty, if the rule has nothing to do
  1.2882 -		       with cancelation.*)
  1.2883 -(* val () = ();
  1.2884 -   *)
  1.2885 -fun locate_rule thy eval_rls ro [rs] t r =
  1.2886 -    if (id_of_thm r) mem (map (id_of_thm)) rs
  1.2887 -    then let val ropt =
  1.2888 -		 rewrite_ thy ro eval_rls true (thm_of_thm r) t;
  1.2889 -	 in case ropt of
  1.2890 -		SOME ta => [(r, ta)]
  1.2891 -	      | NONE => (writeln("### locate_rule:  rewrite "^
  1.2892 -				 (id_of_thm r)^" "^(term2str t)^" = NONE");
  1.2893 -			 []) end
  1.2894 -    else (writeln("### locate_rule:  "^(id_of_thm r)^" not mem rrls");[])
  1.2895 -  | locate_rule _ _ _ _ _ _ =
  1.2896 -    raise error ("locate_rule: doesnt match rev-sets in istate");
  1.2897 -
  1.2898 -(*.next_rule = fn : rule list -> term -> rule option
  1.2899 -  for a given term return the next rules to be done for cancelling.
  1.2900 -arguments:
  1.2901 -  rule list     : the reverse rule list
  1.2902 -  term          : the term for which ...
  1.2903 -value:
  1.2904 -  -> rule option: ... this rule is appropriate for cancellation;
  1.2905 -		  there may be no such rule (if the term is canceled already.*)
  1.2906 -(* val thy = Rational.thy;
  1.2907 -   val Rrls {rew_ord=(_,ro),...} = cancel;
  1.2908 -   val ([rs],t) = (rss,f);
  1.2909 -   next_rule thy eval_rls ro [rs] t;(*eval fun next_rule ... before!*)
  1.2910 -
  1.2911 -   val (thy, [rs]) = (Rational.thy, revsets);
  1.2912 -   val Rrls {rew_ord=(_,ro),...} = cancel;
  1.2913 -   nex [rs] t;
  1.2914 -   *)
  1.2915 -fun next_rule thy eval_rls ro [rs] t =
  1.2916 -    let val der = make_deriv thy eval_rls rs ro NONE t;
  1.2917 -    in case der of
  1.2918 -(* val (_,r,_)::_ = der;
  1.2919 -   *)
  1.2920 -	   (_,r,_)::_ => SOME r
  1.2921 -	 | _ => NONE
  1.2922 -    end
  1.2923 -  | next_rule _ _ _ _ _ =
  1.2924 -    raise error ("next_rule: doesnt match rev-sets in istate");
  1.2925 -
  1.2926 -(*.val attach_form = f : rule list -> term -> term
  1.2927 -			 -> (rule * (term * term list)) list
  1.2928 -  checks an input term TI, if it may belong to a current cancellation, by
  1.2929 -  trying to derive it from the given term TG.
  1.2930 -arguments:
  1.2931 -  term   : TG, the last one in the cancellation agreed upon by user + math-eng
  1.2932 -  -> term: TI, the next one input by the user
  1.2933 -value:
  1.2934 -  -> (rule           : the rule to be applied in order to reach TI
  1.2935 -      * (term        : ... obtained by applying the rule ...
  1.2936 -         * term list): ... and the respective assumptions.
  1.2937 -      ) list         : there may be several such rules;
  1.2938 -                       the list is empty, if the users term does not belong
  1.2939 -		       to a cancellation of the term last agreed upon.*)
  1.2940 -fun attach_form (_:rule list list) (_:term) (_:term) = (*still missing*)
  1.2941 -    []:(rule * (term * term list)) list;
  1.2942 -
  1.2943 -in
  1.2944 -
  1.2945 -val cancel_p =
  1.2946 -    Rrls {id = "cancel_p", prepat=[],
  1.2947 -	  rew_ord=("ord_make_polynomial",
  1.2948 -		   ord_make_polynomial false Rational.thy),
  1.2949 -	  erls = rational_erls,
  1.2950 -	  calc = [("PLUS"    ,("op +"        ,eval_binop "#add_")),
  1.2951 -		  ("TIMES"   ,("op *"        ,eval_binop "#mult_")),
  1.2952 -		  ("DIVIDE" ,("HOL.divide"  ,eval_cancel "#divide_")),
  1.2953 -		  ("POWER"  ,("Atools.pow"  ,eval_binop "#power_"))],
  1.2954 -	  (*asm_thm=[("real_mult_div_cancel2","")],*)
  1.2955 -	  scr=Rfuns {init_state  = init_state thy Atools_erls ro,
  1.2956 -		     normal_form = cancel_p_ thy,
  1.2957 -		     locate_rule = locate_rule thy Atools_erls ro,
  1.2958 -		     next_rule   = next_rule thy Atools_erls ro,
  1.2959 -		     attach_form = attach_form}}
  1.2960 -end;(*local*)
  1.2961 -
  1.2962 -
  1.2963 -local(*.ad (1) 'cancel'
  1.2964 -------------------------------
  1.2965 -cancels a single fraction consisting of two (uni- or multivariate)
  1.2966 -polynomials WN0609???SK[3] into another such a fraction; examples:
  1.2967 -
  1.2968 -	   a^2 - b^2           a + b
  1.2969 -        -------------------- = ---------
  1.2970 -	a^2 - 2*a*b + b^2      a - *b
  1.2971 -
  1.2972 -Remark: the reverse ruleset does _NOT_ work properly with other input !.*)
  1.2973 -(*WN 24.8.02: wir werden "uberlegen, wie wir ungeeignete inputs zur"uckweisen*)
  1.2974 -
  1.2975 -(*
  1.2976 -val SOME (Rls {rules=rules,rew_ord=(_,ro),...}) = 
  1.2977 -    assoc'(!ruleset',"expand_binoms");
  1.2978 -*)
  1.2979 -val {rules=rules,rew_ord=(_,ro),...} =
  1.2980 -    rep_rls (assoc_rls "expand_binoms");
  1.2981 -val thy = Rational.thy;
  1.2982 -
  1.2983 -fun init_state thy eval_rls ro t =
  1.2984 -    let val SOME (t',_) = factout_ thy t;
  1.2985 -        val SOME (t'',asm) = cancel_ thy t;
  1.2986 -        val der = reverse_deriv thy eval_rls rules ro NONE t';
  1.2987 -        val der = der @ [(Thm ("real_mult_div_cancel2",
  1.2988 -			       num_str real_mult_div_cancel2),
  1.2989 -			  (t'',asm))]
  1.2990 -        val rs = map #1 der;
  1.2991 -    in (t,t'',[rs],der) end;
  1.2992 -
  1.2993 -fun locate_rule thy eval_rls ro [rs] t r =
  1.2994 -    if (id_of_thm r) mem (map (id_of_thm)) rs
  1.2995 -    then let val ropt = 
  1.2996 -		 rewrite_ thy ro eval_rls true (thm_of_thm r) t;
  1.2997 -	 in case ropt of
  1.2998 -		SOME ta => [(r, ta)]
  1.2999 -	      | NONE => (writeln("### locate_rule:  rewrite "^
  1.3000 -				 (id_of_thm r)^" "^(term2str t)^" = NONE");
  1.3001 -			 []) end
  1.3002 -    else (writeln("### locate_rule:  "^(id_of_thm r)^" not mem rrls");[])
  1.3003 -  | locate_rule _ _ _ _ _ _ = 
  1.3004 -    raise error ("locate_rule: doesnt match rev-sets in istate");
  1.3005 -
  1.3006 -fun next_rule thy eval_rls ro [rs] t =
  1.3007 -    let val der = make_deriv thy eval_rls rs ro NONE t;
  1.3008 -    in case der of 
  1.3009 -(* val (_,r,_)::_ = der;
  1.3010 -   *)
  1.3011 -	   (_,r,_)::_ => SOME r
  1.3012 -	 | _ => NONE
  1.3013 -    end
  1.3014 -  | next_rule _ _ _ _ _ = 
  1.3015 -    raise error ("next_rule: doesnt match rev-sets in istate");
  1.3016 -
  1.3017 -fun attach_form (_:rule list list) (_:term) (_:term) = (*still missing*)
  1.3018 -    []:(rule * (term * term list)) list;
  1.3019 -
  1.3020 -val pat = (term_of o the o (parse thy)) "?r/?s";
  1.3021 -val pre1 = (term_of o the o (parse thy)) "?r is_expanded";
  1.3022 -val pre2 = (term_of o the o (parse thy)) "?s is_expanded";
  1.3023 -val prepat = [([pre1, pre2], pat)];
  1.3024 -
  1.3025 -in
  1.3026 -
  1.3027 -
  1.3028 -val cancel = 
  1.3029 -    Rrls {id = "cancel", prepat=prepat,
  1.3030 -	  rew_ord=("ord_make_polynomial",
  1.3031 -		   ord_make_polynomial false Rational.thy),
  1.3032 -	  erls = rational_erls, 
  1.3033 -	  calc = [("PLUS"    ,("op +"        ,eval_binop "#add_")),
  1.3034 -		  ("TIMES"   ,("op *"        ,eval_binop "#mult_")),
  1.3035 -		  ("DIVIDE" ,("HOL.divide"  ,eval_cancel "#divide_")),
  1.3036 -		  ("POWER"  ,("Atools.pow"  ,eval_binop "#power_"))],
  1.3037 -	  scr=Rfuns {init_state  = init_state thy Atools_erls ro,
  1.3038 -		     normal_form = cancel_ thy, 
  1.3039 -		     locate_rule = locate_rule thy Atools_erls ro,
  1.3040 -		     next_rule   = next_rule thy Atools_erls ro,
  1.3041 -		     attach_form = attach_form}}
  1.3042 -end;(*local*)
  1.3043 -
  1.3044 -
  1.3045 -
  1.3046 -local(*.ad [2] 'common_nominator_p'
  1.3047 ----------------------------------
  1.3048 -FIXME Beschreibung .*)
  1.3049 -
  1.3050 -
  1.3051 -val {rules=rules,rew_ord=(_,ro),...} =
  1.3052 -    rep_rls (assoc_rls "make_polynomial");
  1.3053 -(*WN060829 ... make_deriv does not terminate with 1st expl above,
  1.3054 -           see rational.sml --- investigate rulesets for cancel_p ---*)
  1.3055 -val {rules, rew_ord=(_,ro),...} =
  1.3056 -    rep_rls (assoc_rls "rev_rew_p");
  1.3057 -val thy = Rational.thy;
  1.3058 -
  1.3059 -
  1.3060 -(*.common_nominator_p_ = fn : theory -> term -> (term * term list) option
  1.3061 -  as defined above*)
  1.3062 -
  1.3063 -(*.init_state = fn : term -> istate
  1.3064 -initialzies the state of the interactive interpreter. The state is:
  1.3065 -
  1.3066 -type rrlsstate =      (*state for reverse rewriting*)
  1.3067 -     (term *          (*the current formula*)
  1.3068 -      term *          (*the final term*)
  1.3069 -      rule list       (*'reverse rule list' (#)*)
  1.3070 -	    list *    (*may be serveral, eg. in norm_rational*)
  1.3071 -      (rule *         (*Thm (+ Thm generated from Calc) resulting in ...*)
  1.3072 -       (term *        (*... rewrite with ...*)
  1.3073 -	term list))   (*... assumptions*)
  1.3074 -	  list);      (*derivation from given term to normalform
  1.3075 -		       in reverse order with sym_thm;
  1.3076 -                       (#) could be extracted from here by (map #1)*).*)
  1.3077 -fun init_state thy eval_rls ro t =
  1.3078 -    let val SOME (t',_) = common_nominator_p_ thy t;
  1.3079 -        val SOME (t'',asm) = add_fraction_p_ thy t;
  1.3080 -        val der = reverse_deriv thy eval_rls rules ro NONE t';
  1.3081 -        val der = der @ [(Thm ("real_mult_div_cancel2",
  1.3082 -			       num_str real_mult_div_cancel2),
  1.3083 -			  (t'',asm))]
  1.3084 -        val rs = (distinct_Thm o (map #1)) der;
  1.3085 -	val rs = filter_out (eq_Thms ["sym_real_add_zero_left",
  1.3086 -				      "sym_real_mult_0",
  1.3087 -				      "sym_real_mult_1"]) rs;
  1.3088 -    in (t,t'',[rs(*here only _ONE_*)],der) end;
  1.3089 -
  1.3090 -(* use"knowledge/Rational.ML";
  1.3091 -   *)
  1.3092 -
  1.3093 -(*.locate_rule = fn : rule list -> term -> rule
  1.3094 -		      -> (rule * (term * term list) option) list.
  1.3095 -  checks a rule R for being a cancel-rule, and if it is,
  1.3096 -  then return the list of rules (+ the terms they are rewriting to)
  1.3097 -  which need to be applied before R should be applied.
  1.3098 -  precondition: the rule is applicable to the argument-term.
  1.3099 -arguments:
  1.3100 -  rule list: the reverse rule list
  1.3101 -  -> term  : ... to which the rule shall be applied
  1.3102 -  -> rule  : ... to be applied to term
  1.3103 -value:
  1.3104 -  -> (rule           : a rule rewriting to ...
  1.3105 -      * (term        : ... the resulting term ...
  1.3106 -         * term list): ... with the assumptions ( //#0).
  1.3107 -      ) list         : there may be several such rules;
  1.3108 -		       the list is empty, if the rule has nothing to do
  1.3109 -		       with cancelation.*)
  1.3110 -(* val () = ();
  1.3111 -   *)
  1.3112 -fun locate_rule thy eval_rls ro [rs] t r =
  1.3113 -    if (id_of_thm r) mem (map (id_of_thm)) rs
  1.3114 -    then let val ropt =
  1.3115 -		 rewrite_ thy ro eval_rls true (thm_of_thm r) t;
  1.3116 -	 in case ropt of
  1.3117 -		SOME ta => [(r, ta)]
  1.3118 -	      | NONE => (writeln("### locate_rule:  rewrite "^
  1.3119 -				 (id_of_thm r)^" "^(term2str t)^" = NONE");
  1.3120 -			 []) end
  1.3121 -    else (writeln("### locate_rule:  "^(id_of_thm r)^" not mem rrls");[])
  1.3122 -  | locate_rule _ _ _ _ _ _ =
  1.3123 -    raise error ("locate_rule: doesnt match rev-sets in istate");
  1.3124 -
  1.3125 -(*.next_rule = fn : rule list -> term -> rule option
  1.3126 -  for a given term return the next rules to be done for cancelling.
  1.3127 -arguments:
  1.3128 -  rule list     : the reverse rule list
  1.3129 -  term          : the term for which ...
  1.3130 -value:
  1.3131 -  -> rule option: ... this rule is appropriate for cancellation;
  1.3132 -		  there may be no such rule (if the term is canceled already.*)
  1.3133 -(* val thy = Rational.thy;
  1.3134 -   val Rrls {rew_ord=(_,ro),...} = cancel;
  1.3135 -   val ([rs],t) = (rss,f);
  1.3136 -   next_rule thy eval_rls ro [rs] t;(*eval fun next_rule ... before!*)
  1.3137 -
  1.3138 -   val (thy, [rs]) = (Rational.thy, revsets);
  1.3139 -   val Rrls {rew_ord=(_,ro),...} = cancel;
  1.3140 -   nex [rs] t;
  1.3141 -   *)
  1.3142 -fun next_rule thy eval_rls ro [rs] t =
  1.3143 -    let val der = make_deriv thy eval_rls rs ro NONE t;
  1.3144 -    in case der of
  1.3145 -(* val (_,r,_)::_ = der;
  1.3146 -   *)
  1.3147 -	   (_,r,_)::_ => SOME r
  1.3148 -	 | _ => NONE
  1.3149 -    end
  1.3150 -  | next_rule _ _ _ _ _ =
  1.3151 -    raise error ("next_rule: doesnt match rev-sets in istate");
  1.3152 -
  1.3153 -(*.val attach_form = f : rule list -> term -> term
  1.3154 -			 -> (rule * (term * term list)) list
  1.3155 -  checks an input term TI, if it may belong to a current cancellation, by
  1.3156 -  trying to derive it from the given term TG.
  1.3157 -arguments:
  1.3158 -  term   : TG, the last one in the cancellation agreed upon by user + math-eng
  1.3159 -  -> term: TI, the next one input by the user
  1.3160 -value:
  1.3161 -  -> (rule           : the rule to be applied in order to reach TI
  1.3162 -      * (term        : ... obtained by applying the rule ...
  1.3163 -         * term list): ... and the respective assumptions.
  1.3164 -      ) list         : there may be several such rules;
  1.3165 -                       the list is empty, if the users term does not belong
  1.3166 -		       to a cancellation of the term last agreed upon.*)
  1.3167 -fun attach_form (_:rule list list) (_:term) (_:term) = (*still missing*)
  1.3168 -    []:(rule * (term * term list)) list;
  1.3169 -
  1.3170 -val pat0 = (term_of o the o (parse thy)) "?r/?s+?u/?v";
  1.3171 -val pat1 = (term_of o the o (parse thy)) "?r/?s+?u   ";
  1.3172 -val pat2 = (term_of o the o (parse thy)) "?r   +?u/?v";
  1.3173 -val prepat = [([HOLogic.true_const], pat0),
  1.3174 -	      ([HOLogic.true_const], pat1),
  1.3175 -	      ([HOLogic.true_const], pat2)];
  1.3176 -
  1.3177 -in
  1.3178 -
  1.3179 -(*11.02 schnelle L"osung f"ur RL: Bruch auch gek"urzt;
  1.3180 -  besser w"are: auf 1 gemeinsamen Bruchstrich, Nenner und Z"ahler unvereinfacht
  1.3181 -  dh. wie common_nominator_p_, aber auf 1 Bruchstrich*)
  1.3182 -val common_nominator_p =
  1.3183 -    Rrls {id = "common_nominator_p", prepat=prepat,
  1.3184 -	  rew_ord=("ord_make_polynomial",
  1.3185 -		   ord_make_polynomial false Rational.thy),
  1.3186 -	  erls = rational_erls,
  1.3187 -	  calc = [("PLUS"    ,("op +"        ,eval_binop "#add_")),
  1.3188 -		  ("TIMES"   ,("op *"        ,eval_binop "#mult_")),
  1.3189 -		  ("DIVIDE" ,("HOL.divide"  ,eval_cancel "#divide_")),
  1.3190 -		  ("POWER"  ,("Atools.pow"  ,eval_binop "#power_"))],
  1.3191 -	  scr=Rfuns {init_state  = init_state thy Atools_erls ro,
  1.3192 -		     normal_form = add_fraction_p_ thy,(*FIXME.WN0211*)
  1.3193 -		     locate_rule = locate_rule thy Atools_erls ro,
  1.3194 -		     next_rule   = next_rule thy Atools_erls ro,
  1.3195 -		     attach_form = attach_form}}
  1.3196 -end;(*local*)
  1.3197 -
  1.3198 -
  1.3199 -local(*.ad [2] 'common_nominator'
  1.3200 ----------------------------------
  1.3201 -FIXME Beschreibung .*)
  1.3202 -
  1.3203 -
  1.3204 -val {rules=rules,rew_ord=(_,ro),...} =
  1.3205 -    rep_rls (assoc_rls "make_polynomial");
  1.3206 -val thy = Rational.thy;
  1.3207 -
  1.3208 -
  1.3209 -(*.common_nominator_ = fn : theory -> term -> (term * term list) option
  1.3210 -  as defined above*)
  1.3211 -
  1.3212 -(*.init_state = fn : term -> istate
  1.3213 -initialzies the state of the interactive interpreter. The state is:
  1.3214 -
  1.3215 -type rrlsstate =      (*state for reverse rewriting*)
  1.3216 -     (term *          (*the current formula*)
  1.3217 -      term *          (*the final term*)
  1.3218 -      rule list       (*'reverse rule list' (#)*)
  1.3219 -	    list *    (*may be serveral, eg. in norm_rational*)
  1.3220 -      (rule *         (*Thm (+ Thm generated from Calc) resulting in ...*)
  1.3221 -       (term *        (*... rewrite with ...*)
  1.3222 -	term list))   (*... assumptions*)
  1.3223 -	  list);      (*derivation from given term to normalform
  1.3224 -		       in reverse order with sym_thm;
  1.3225 -                       (#) could be extracted from here by (map #1)*).*)
  1.3226 -fun init_state thy eval_rls ro t =
  1.3227 -    let val SOME (t',_) = common_nominator_ thy t;
  1.3228 -        val SOME (t'',asm) = add_fraction_ thy t;
  1.3229 -        val der = reverse_deriv thy eval_rls rules ro NONE t';
  1.3230 -        val der = der @ [(Thm ("real_mult_div_cancel2",
  1.3231 -			       num_str real_mult_div_cancel2),
  1.3232 -			  (t'',asm))]
  1.3233 -        val rs = (distinct_Thm o (map #1)) der;
  1.3234 -	val rs = filter_out (eq_Thms ["sym_real_add_zero_left",
  1.3235 -				      "sym_real_mult_0",
  1.3236 -				      "sym_real_mult_1"]) rs;
  1.3237 -    in (t,t'',[rs(*here only _ONE_*)],der) end;
  1.3238 -
  1.3239 -(* use"knowledge/Rational.ML";
  1.3240 -   *)
  1.3241 -
  1.3242 -(*.locate_rule = fn : rule list -> term -> rule
  1.3243 -		      -> (rule * (term * term list) option) list.
  1.3244 -  checks a rule R for being a cancel-rule, and if it is,
  1.3245 -  then return the list of rules (+ the terms they are rewriting to)
  1.3246 -  which need to be applied before R should be applied.
  1.3247 -  precondition: the rule is applicable to the argument-term.
  1.3248 -arguments:
  1.3249 -  rule list: the reverse rule list
  1.3250 -  -> term  : ... to which the rule shall be applied
  1.3251 -  -> rule  : ... to be applied to term
  1.3252 -value:
  1.3253 -  -> (rule           : a rule rewriting to ...
  1.3254 -      * (term        : ... the resulting term ...
  1.3255 -         * term list): ... with the assumptions ( //#0).
  1.3256 -      ) list         : there may be several such rules;
  1.3257 -		       the list is empty, if the rule has nothing to do
  1.3258 -		       with cancelation.*)
  1.3259 -(* val () = ();
  1.3260 -   *)
  1.3261 -fun locate_rule thy eval_rls ro [rs] t r =
  1.3262 -    if (id_of_thm r) mem (map (id_of_thm)) rs
  1.3263 -    then let val ropt =
  1.3264 -		 rewrite_ thy ro eval_rls true (thm_of_thm r) t;
  1.3265 -	 in case ropt of
  1.3266 -		SOME ta => [(r, ta)]
  1.3267 -	      | NONE => (writeln("### locate_rule:  rewrite "^
  1.3268 -				 (id_of_thm r)^" "^(term2str t)^" = NONE");
  1.3269 -			 []) end
  1.3270 -    else (writeln("### locate_rule:  "^(id_of_thm r)^" not mem rrls");[])
  1.3271 -  | locate_rule _ _ _ _ _ _ =
  1.3272 -    raise error ("locate_rule: doesnt match rev-sets in istate");
  1.3273 -
  1.3274 -(*.next_rule = fn : rule list -> term -> rule option
  1.3275 -  for a given term return the next rules to be done for cancelling.
  1.3276 -arguments:
  1.3277 -  rule list     : the reverse rule list
  1.3278 -  term          : the term for which ...
  1.3279 -value:
  1.3280 -  -> rule option: ... this rule is appropriate for cancellation;
  1.3281 -		  there may be no such rule (if the term is canceled already.*)
  1.3282 -(* val thy = Rational.thy;
  1.3283 -   val Rrls {rew_ord=(_,ro),...} = cancel;
  1.3284 -   val ([rs],t) = (rss,f);
  1.3285 -   next_rule thy eval_rls ro [rs] t;(*eval fun next_rule ... before!*)
  1.3286 -
  1.3287 -   val (thy, [rs]) = (Rational.thy, revsets);
  1.3288 -   val Rrls {rew_ord=(_,ro),...} = cancel_p;
  1.3289 -   nex [rs] t;
  1.3290 -   *)
  1.3291 -fun next_rule thy eval_rls ro [rs] t =
  1.3292 -    let val der = make_deriv thy eval_rls rs ro NONE t;
  1.3293 -    in case der of
  1.3294 -(* val (_,r,_)::_ = der;
  1.3295 -   *)
  1.3296 -	   (_,r,_)::_ => SOME r
  1.3297 -	 | _ => NONE
  1.3298 -    end
  1.3299 -  | next_rule _ _ _ _ _ =
  1.3300 -    raise error ("next_rule: doesnt match rev-sets in istate");
  1.3301 -
  1.3302 -(*.val attach_form = f : rule list -> term -> term
  1.3303 -			 -> (rule * (term * term list)) list
  1.3304 -  checks an input term TI, if it may belong to a current cancellation, by
  1.3305 -  trying to derive it from the given term TG.
  1.3306 -arguments:
  1.3307 -  term   : TG, the last one in the cancellation agreed upon by user + math-eng
  1.3308 -  -> term: TI, the next one input by the user
  1.3309 -value:
  1.3310 -  -> (rule           : the rule to be applied in order to reach TI
  1.3311 -      * (term        : ... obtained by applying the rule ...
  1.3312 -         * term list): ... and the respective assumptions.
  1.3313 -      ) list         : there may be several such rules;
  1.3314 -                       the list is empty, if the users term does not belong
  1.3315 -		       to a cancellation of the term last agreed upon.*)
  1.3316 -fun attach_form (_:rule list list) (_:term) (_:term) = (*still missing*)
  1.3317 -    []:(rule * (term * term list)) list;
  1.3318 -
  1.3319 -val pat0 =  (term_of o the o (parse thy)) "?r/?s+?u/?v";
  1.3320 -val pat01 = (term_of o the o (parse thy)) "?r/?s-?u/?v";
  1.3321 -val pat1 =  (term_of o the o (parse thy)) "?r/?s+?u   ";
  1.3322 -val pat11 = (term_of o the o (parse thy)) "?r/?s-?u   ";
  1.3323 -val pat2 =  (term_of o the o (parse thy)) "?r   +?u/?v";
  1.3324 -val pat21 = (term_of o the o (parse thy)) "?r   -?u/?v";
  1.3325 -val prepat = [([HOLogic.true_const], pat0),
  1.3326 -	      ([HOLogic.true_const], pat01),
  1.3327 -	      ([HOLogic.true_const], pat1),
  1.3328 -	      ([HOLogic.true_const], pat11),
  1.3329 -	      ([HOLogic.true_const], pat2),
  1.3330 -	      ([HOLogic.true_const], pat21)];
  1.3331 -
  1.3332 -
  1.3333 -in
  1.3334 -
  1.3335 -val common_nominator =
  1.3336 -    Rrls {id = "common_nominator", prepat=prepat,
  1.3337 -	  rew_ord=("ord_make_polynomial",
  1.3338 -		   ord_make_polynomial false Rational.thy),
  1.3339 -	  erls = rational_erls,
  1.3340 -	  calc = [("PLUS"    ,("op +"        ,eval_binop "#add_")),
  1.3341 -		  ("TIMES"   ,("op *"        ,eval_binop "#mult_")),
  1.3342 -		  ("DIVIDE" ,("HOL.divide"  ,eval_cancel "#divide_")),
  1.3343 -		  ("POWER"  ,("Atools.pow"  ,eval_binop "#power_"))],
  1.3344 -	  (*asm_thm=[("real_mult_div_cancel2","")],*)
  1.3345 -	  scr=Rfuns {init_state  = init_state thy Atools_erls ro,
  1.3346 -		     normal_form = add_fraction_ (*NOT common_nominator_*) thy,
  1.3347 -		     locate_rule = locate_rule thy Atools_erls ro,
  1.3348 -		     next_rule   = next_rule thy Atools_erls ro,
  1.3349 -		     attach_form = attach_form}}
  1.3350 -
  1.3351 -end;(*local*)
  1.3352 -
  1.3353 -
  1.3354 -(*##*)
  1.3355 -end;(*struct*)
  1.3356 -
  1.3357 -open RationalI;
  1.3358 -(*##*)
  1.3359 -
  1.3360 -(*.the expression contains + - * ^ / only ?.*)
  1.3361 -fun is_ratpolyexp (Free _) = true
  1.3362 -  | is_ratpolyexp (Const ("op +",_) $ Free _ $ Free _) = true
  1.3363 -  | is_ratpolyexp (Const ("op -",_) $ Free _ $ Free _) = true
  1.3364 -  | is_ratpolyexp (Const ("op *",_) $ Free _ $ Free _) = true
  1.3365 -  | is_ratpolyexp (Const ("Atools.pow",_) $ Free _ $ Free _) = true
  1.3366 -  | is_ratpolyexp (Const ("HOL.divide",_) $ Free _ $ Free _) = true
  1.3367 -  | is_ratpolyexp (Const ("op +",_) $ t1 $ t2) = 
  1.3368 -               ((is_ratpolyexp t1) andalso (is_ratpolyexp t2))
  1.3369 -  | is_ratpolyexp (Const ("op -",_) $ t1 $ t2) = 
  1.3370 -               ((is_ratpolyexp t1) andalso (is_ratpolyexp t2))
  1.3371 -  | is_ratpolyexp (Const ("op *",_) $ t1 $ t2) = 
  1.3372 -               ((is_ratpolyexp t1) andalso (is_ratpolyexp t2))
  1.3373 -  | is_ratpolyexp (Const ("Atools.pow",_) $ t1 $ t2) = 
  1.3374 -               ((is_ratpolyexp t1) andalso (is_ratpolyexp t2))
  1.3375 -  | is_ratpolyexp (Const ("HOL.divide",_) $ t1 $ t2) = 
  1.3376 -               ((is_ratpolyexp t1) andalso (is_ratpolyexp t2))
  1.3377 -  | is_ratpolyexp _ = false;
  1.3378 -
  1.3379 -(*("is_ratpolyexp", ("Rational.is'_ratpolyexp", eval_is_ratpolyexp ""))*)
  1.3380 -fun eval_is_ratpolyexp (thmid:string) _ 
  1.3381 -		       (t as (Const("Rational.is'_ratpolyexp", _) $ arg)) thy =
  1.3382 -    if is_ratpolyexp arg
  1.3383 -    then SOME (mk_thmid thmid "" 
  1.3384 -			((Syntax.string_of_term (thy2ctxt thy)) arg) "", 
  1.3385 -	       Trueprop $ (mk_equality (t, HOLogic.true_const)))
  1.3386 -    else SOME (mk_thmid thmid "" 
  1.3387 -			((Syntax.string_of_term (thy2ctxt thy)) arg) "", 
  1.3388 -	       Trueprop $ (mk_equality (t, HOLogic.false_const)))
  1.3389 -  | eval_is_ratpolyexp _ _ _ _ = NONE; 
  1.3390 -
  1.3391 -
  1.3392 -
  1.3393 -(*-------------------18.3.03 --> struct <-----------vvv--*)
  1.3394 -val add_fractions_p = common_nominator_p; (*FIXXXME:eilig f"ur norm_Rational*)
  1.3395 -
  1.3396 -(*.discard binary minus, shift unary minus into -1*; 
  1.3397 -   unary minus before numerals are put into the numeral by parsing;
  1.3398 -   contains absolute minimum of thms for context in norm_Rational .*)
  1.3399 -val discard_minus = prep_rls(
  1.3400 -  Rls {id = "discard_minus", preconds = [], rew_ord = ("dummy_ord",dummy_ord), 
  1.3401 -      erls = e_rls, srls = Erls, calc = [], (*asm_thm = [],*)
  1.3402 -      rules = [Thm ("real_diff_minus", num_str real_diff_minus),
  1.3403 -	       (*"a - b = a + -1 * b"*)
  1.3404 -	       Thm ("sym_real_mult_minus1",num_str (real_mult_minus1 RS sym))
  1.3405 -	       (*- ?z = "-1 * ?z"*)
  1.3406 -	       ],
  1.3407 -      scr = Script ((term_of o the o (parse thy)) 
  1.3408 -      "empty_script")
  1.3409 -      }):rls;
  1.3410 -(*erls for calculate_Rational; make local with FIXX@ME result:term *term list*)
  1.3411 -val powers_erls = prep_rls(
  1.3412 -  Rls {id = "powers_erls", preconds = [], rew_ord = ("dummy_ord",dummy_ord), 
  1.3413 -      erls = e_rls, srls = Erls, calc = [], (*asm_thm = [],*)
  1.3414 -      rules = [Calc ("Atools.is'_atom",eval_is_atom "#is_atom_"),
  1.3415 -	       Calc ("Atools.is'_even",eval_is_even "#is_even_"),
  1.3416 -	       Calc ("op <",eval_equ "#less_"),
  1.3417 -	       Thm ("not_false", not_false),
  1.3418 -	       Thm ("not_true", not_true),
  1.3419 -	       Calc ("op +",eval_binop "#add_")
  1.3420 -	       ],
  1.3421 -      scr = Script ((term_of o the o (parse thy)) 
  1.3422 -      "empty_script")
  1.3423 -      }:rls);
  1.3424 -(*.all powers over + distributed; atoms over * collected, other distributed
  1.3425 -   contains absolute minimum of thms for context in norm_Rational .*)
  1.3426 -val powers = prep_rls(
  1.3427 -  Rls {id = "powers", preconds = [], rew_ord = ("dummy_ord",dummy_ord), 
  1.3428 -      erls = powers_erls, srls = Erls, calc = [], (*asm_thm = [],*)
  1.3429 -      rules = [Thm ("realpow_multI", num_str realpow_multI),
  1.3430 -	       (*"(r * s) ^^^ n = r ^^^ n * s ^^^ n"*)
  1.3431 -	       Thm ("realpow_pow",num_str realpow_pow),
  1.3432 -	       (*"(a ^^^ b) ^^^ c = a ^^^ (b * c)"*)
  1.3433 -	       Thm ("realpow_oneI",num_str realpow_oneI),
  1.3434 -	       (*"r ^^^ 1 = r"*)
  1.3435 -	       Thm ("realpow_minus_even",num_str realpow_minus_even),
  1.3436 -	       (*"n is_even ==> (- r) ^^^ n = r ^^^ n" ?-->discard_minus?*)
  1.3437 -	       Thm ("realpow_minus_odd",num_str realpow_minus_odd),
  1.3438 -	       (*"Not (n is_even) ==> (- r) ^^^ n = -1 * r ^^^ n"*)
  1.3439 -	       
  1.3440 -	       (*----- collect atoms over * -----*)
  1.3441 -	       Thm ("realpow_two_atom",num_str realpow_two_atom),	
  1.3442 -	       (*"r is_atom ==> r * r = r ^^^ 2"*)
  1.3443 -	       Thm ("realpow_plus_1",num_str realpow_plus_1),		
  1.3444 -	       (*"r is_atom ==> r * r ^^^ n = r ^^^ (n + 1)"*)
  1.3445 -	       Thm ("realpow_addI_atom",num_str realpow_addI_atom),
  1.3446 -	       (*"r is_atom ==> r ^^^ n * r ^^^ m = r ^^^ (n + m)"*)
  1.3447 -
  1.3448 -	       (*----- distribute none-atoms -----*)
  1.3449 -	       Thm ("realpow_def_atom",num_str realpow_def_atom),
  1.3450 -	       (*"[| 1 < n; not(r is_atom) |]==>r ^^^ n = r * r ^^^ (n + -1)"*)
  1.3451 -	       Thm ("realpow_eq_oneI",num_str realpow_eq_oneI),
  1.3452 -	       (*"1 ^^^ n = 1"*)
  1.3453 -	       Calc ("op +",eval_binop "#add_")
  1.3454 -	       ],
  1.3455 -      scr = Script ((term_of o the o (parse thy)) 
  1.3456 -      "empty_script")
  1.3457 -      }:rls);
  1.3458 -(*.contains absolute minimum of thms for context in norm_Rational.*)
  1.3459 -val rat_mult_divide = prep_rls(
  1.3460 -  Rls {id = "rat_mult_divide", preconds = [], 
  1.3461 -       rew_ord = ("dummy_ord",dummy_ord), 
  1.3462 -      erls = e_rls, srls = Erls, calc = [], (*asm_thm = [],*)
  1.3463 -      rules = [Thm ("rat_mult",num_str rat_mult),
  1.3464 -	       (*(1)"?a / ?b * (?c / ?d) = ?a * ?c / (?b * ?d)"*)
  1.3465 -	       Thm ("real_times_divide1_eq",num_str real_times_divide1_eq),
  1.3466 -	       (*(2)"?a * (?c / ?d) = ?a * ?c / ?d" must be [2],
  1.3467 -	       otherwise inv.to a / b / c = ...*)
  1.3468 -	       Thm ("real_times_divide2_eq",num_str real_times_divide2_eq),
  1.3469 -	       (*"?a / ?b * ?c = ?a * ?c / ?b" order weights x^^^n too much
  1.3470 -		     and does not commute a / b * c ^^^ 2 !*)
  1.3471 -	       
  1.3472 -	       Thm ("real_divide_divide1_eq", real_divide_divide1_eq),
  1.3473 -	       (*"?x / (?y / ?z) = ?x * ?z / ?y"*)
  1.3474 -	       Thm ("real_divide_divide2_eq", real_divide_divide2_eq),
  1.3475 -	       (*"?x / ?y / ?z = ?x / (?y * ?z)"*)
  1.3476 -	       Calc ("HOL.divide"  ,eval_cancel "#divide_")
  1.3477 -	       ],
  1.3478 -      scr = Script ((term_of o the o (parse thy)) "empty_script")
  1.3479 -      }:rls);
  1.3480 -(*.contains absolute minimum of thms for context in norm_Rational.*)
  1.3481 -val reduce_0_1_2 = prep_rls(
  1.3482 -  Rls{id = "reduce_0_1_2", preconds = [], rew_ord = ("dummy_ord", dummy_ord),
  1.3483 -      erls = e_rls,srls = Erls,calc = [],(*asm_thm = [],*)
  1.3484 -      rules = [(*Thm ("real_divide_1",num_str real_divide_1),
  1.3485 -		 "?x / 1 = ?x" unnecess.for normalform*)
  1.3486 -	       Thm ("real_mult_1",num_str real_mult_1),                 
  1.3487 -	       (*"1 * z = z"*)
  1.3488 -	       (*Thm ("real_mult_minus1",num_str real_mult_minus1),
  1.3489 -	       "-1 * z = - z"*)
  1.3490 -	       (*Thm ("real_minus_mult_cancel",num_str real_minus_mult_cancel),
  1.3491 -	       "- ?x * - ?y = ?x * ?y"*)
  1.3492 -
  1.3493 -	       Thm ("real_mult_0",num_str real_mult_0),        
  1.3494 -	       (*"0 * z = 0"*)
  1.3495 -	       Thm ("real_add_zero_left",num_str real_add_zero_left),
  1.3496 -	       (*"0 + z = z"*)
  1.3497 -	       (*Thm ("real_add_minus",num_str real_add_minus),
  1.3498 -	       "?z + - ?z = 0"*)
  1.3499 -
  1.3500 -	       Thm ("sym_real_mult_2",num_str (real_mult_2 RS sym)),	
  1.3501 -	       (*"z1 + z1 = 2 * z1"*)
  1.3502 -	       Thm ("real_mult_2_assoc",num_str real_mult_2_assoc),
  1.3503 -	       (*"z1 + (z1 + k) = 2 * z1 + k"*)
  1.3504 -
  1.3505 -	       Thm ("real_0_divide",num_str real_0_divide)
  1.3506 -	       (*"0 / ?x = 0"*)
  1.3507 -	       ], scr = EmptyScr}:rls);
  1.3508 -
  1.3509 -(*erls for calculate_Rational; 
  1.3510 -  make local with FIXX@ME result:term *term list WN0609???SKMG*)
  1.3511 -val norm_rat_erls = prep_rls(
  1.3512 -  Rls {id = "norm_rat_erls", preconds = [], rew_ord = ("dummy_ord",dummy_ord), 
  1.3513 -      erls = e_rls, srls = Erls, calc = [], (*asm_thm = [],*)
  1.3514 -      rules = [Calc ("Atools.is'_const",eval_const "#is_const_")
  1.3515 -	       ],
  1.3516 -      scr = Script ((term_of o the o (parse thy)) 
  1.3517 -      "empty_script")
  1.3518 -      }:rls);
  1.3519 -(*.consists of rls containing the absolute minimum of thms.*)
  1.3520 -(*040209: this version has been used by RL for his equations,
  1.3521 -which is now replaced by MGs version below
  1.3522 -vvv OLD VERSION !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!*)
  1.3523 -val norm_Rational = prep_rls(
  1.3524 -  Rls {id = "norm_Rational", preconds = [], rew_ord = ("dummy_ord",dummy_ord), 
  1.3525 -      erls = norm_rat_erls, srls = Erls, calc = [], (*asm_thm = [],*)
  1.3526 -      rules = [(*sequence given by operator precedence*)
  1.3527 -	       Rls_ discard_minus,
  1.3528 -	       Rls_ powers,
  1.3529 -	       Rls_ rat_mult_divide,
  1.3530 -	       Rls_ expand,
  1.3531 -	       Rls_ reduce_0_1_2,
  1.3532 -	       (*^^^^^^^^^ from RL -- not the latest one vvvvvvvvv*)
  1.3533 -	       Rls_ order_add_mult,
  1.3534 -	       Rls_ collect_numerals,
  1.3535 -	       Rls_ add_fractions_p,
  1.3536 -	       Rls_ cancel_p
  1.3537 -	       ],
  1.3538 -      scr = Script ((term_of o the o (parse thy)) 
  1.3539 -      "empty_script")
  1.3540 -      }:rls);
  1.3541 -val norm_Rational_parenthesized = prep_rls(
  1.3542 -  Seq {id = "norm_Rational_parenthesized", preconds = []:term list, 
  1.3543 -       rew_ord = ("dummy_ord", dummy_ord),
  1.3544 -      erls = Atools_erls, srls = Erls,
  1.3545 -      calc = [], (*asm_thm = [],*)
  1.3546 -      rules = [Rls_  norm_Rational, (*from RL -- not the latest one*)
  1.3547 -	       Rls_ discard_parentheses
  1.3548 -	       ],
  1.3549 -      scr = EmptyScr
  1.3550 -      }:rls);      
  1.3551 -
  1.3552 -
  1.3553 -(*-------------------18.3.03 --> struct <-----------^^^--*)
  1.3554 -
  1.3555 -
  1.3556 -
  1.3557 -theory' := overwritel (!theory', [("Rational.thy",Rational.thy)]);
  1.3558 -
  1.3559 -
  1.3560 -(*WN030318???SK: simplifies all but cancel and common_nominator*)
  1.3561 -val simplify_rational = 
  1.3562 -    merge_rls "simplify_rational" expand_binoms
  1.3563 -    (append_rls "divide" calculate_Rational
  1.3564 -		[Thm ("real_divide_1",num_str real_divide_1),
  1.3565 -		 (*"?x / 1 = ?x"*)
  1.3566 -		 Thm ("rat_mult",num_str rat_mult),
  1.3567 -		 (*(1)"?a / ?b * (?c / ?d) = ?a * ?c / (?b * ?d)"*)
  1.3568 -		 Thm ("real_times_divide1_eq",num_str real_times_divide1_eq),
  1.3569 -		 (*(2)"?a * (?c / ?d) = ?a * ?c / ?d" must be [2],
  1.3570 -		 otherwise inv.to a / b / c = ...*)
  1.3571 -		 Thm ("real_times_divide2_eq",num_str real_times_divide2_eq),
  1.3572 -		 (*"?a / ?b * ?c = ?a * ?c / ?b"*)
  1.3573 -		 Thm ("add_minus",num_str add_minus),
  1.3574 -		 (*"?a + ?b - ?b = ?a"*)
  1.3575 -		 Thm ("add_minus1",num_str add_minus1),
  1.3576 -		 (*"?a - ?b + ?b = ?a"*)
  1.3577 -		 Thm ("real_divide_minus1",num_str real_divide_minus1)
  1.3578 -		 (*"?x / -1 = - ?x"*)
  1.3579 -(*
  1.3580 -,
  1.3581 -		 Thm ("",num_str )
  1.3582 -*)
  1.3583 -		 ]);
  1.3584 -
  1.3585 -(*---------vvv-------------MG ab 1.07.2003--------------vvv-----------*)
  1.3586 -
  1.3587 -(* ------------------------------------------------------------------ *)
  1.3588 -(*                  Simplifier für beliebige Buchterme                *) 
  1.3589 -(* ------------------------------------------------------------------ *)
  1.3590 -(*----------------------- norm_Rational_mg ---------------------------*)
  1.3591 -(*. description of the simplifier see MG-DA.p.56ff .*)
  1.3592 -(* ------------------------------------------------------------------- *)
  1.3593 -val common_nominator_p_rls = prep_rls(
  1.3594 -  Rls {id = "common_nominator_p_rls", preconds = [],
  1.3595 -       rew_ord = ("dummy_ord",dummy_ord), 
  1.3596 -	 erls = e_rls, srls = Erls, calc = [],
  1.3597 -	 rules = 
  1.3598 -	 [Rls_ common_nominator_p
  1.3599 -	  (*FIXME.WN0401 ? redesign Rrls - use exhaustively on a term ?
  1.3600 -	    FIXME.WN0510 unnecessary nesting: introduce RRls_ : rls -> rule*)
  1.3601 -	  ], 
  1.3602 -	 scr = EmptyScr});
  1.3603 -(* ------------------------------------------------------------------- *)
  1.3604 -val cancel_p_rls = prep_rls(
  1.3605 -  Rls {id = "cancel_p_rls", preconds = [],
  1.3606 -       rew_ord = ("dummy_ord",dummy_ord), 
  1.3607 -	 erls = e_rls, srls = Erls, calc = [],
  1.3608 -	 rules = 
  1.3609 -	 [Rls_ cancel_p
  1.3610 -	  (*FIXME.WN.0401 ? redesign Rrls - use exhaustively on a term ?*)
  1.3611 -	  ], 
  1.3612 -	 scr = EmptyScr});
  1.3613 -(* -------------------------------------------------------------------- *)
  1.3614 -(*. makes 'normal' fractions; 'is_polyexp' inhibits double fractions;
  1.3615 -    used in initial part norm_Rational_mg, see example DA-M02-main.p.60.*)
  1.3616 -val rat_mult_poly = prep_rls(
  1.3617 -  Rls {id = "rat_mult_poly", preconds = [],
  1.3618 -       rew_ord = ("dummy_ord",dummy_ord), 
  1.3619 -	 erls =  append_rls "e_rls-is_polyexp" e_rls
  1.3620 -	         [Calc ("Poly.is'_polyexp", eval_is_polyexp "")], 
  1.3621 -	 srls = Erls, calc = [],
  1.3622 -	 rules = 
  1.3623 -	 [Thm ("rat_mult_poly_l",num_str rat_mult_poly_l),
  1.3624 -	  (*"?c is_polyexp ==> ?c * (?a / ?b) = ?c * ?a / ?b"*)
  1.3625 -	  Thm ("rat_mult_poly_r",num_str rat_mult_poly_r)
  1.3626 -	  (*"?c is_polyexp ==> ?a / ?b * ?c = ?a * ?c / ?b"*)
  1.3627 -	  ], 
  1.3628 -	 scr = EmptyScr});
  1.3629 -(* ------------------------------------------------------------------ *)
  1.3630 -(*. makes 'normal' fractions; 'is_polyexp' inhibits double fractions;
  1.3631 -    used in looping part norm_Rational_rls, see example DA-M02-main.p.60 
  1.3632 -    .. WHERE THE LATTER DOES ALWAYS WORK, BECAUSE erls = e_rls, 
  1.3633 -    I.E. THE RESPECTIVE ASSUMPTION IS STORED AND Thm APPLIED; WN051028 
  1.3634 -    ... WN0609???MG.*)
  1.3635 -val rat_mult_div_pow = prep_rls(
  1.3636 -  Rls {id = "rat_mult_div_pow", preconds = [], 
  1.3637 -       rew_ord = ("dummy_ord",dummy_ord), 
  1.3638 -       erls = e_rls,
  1.3639 -       (*FIXME.WN051028 append_rls "e_rls-is_polyexp" e_rls
  1.3640 -			[Calc ("Poly.is'_polyexp", eval_is_polyexp "")],
  1.3641 -         with this correction ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ we get 
  1.3642 -	 error "rational.sml.sml: diff.behav. in norm_Rational_mg 29" etc.
  1.3643 -         thus we decided to go on with this flaw*)
  1.3644 -		 srls = Erls, calc = [],
  1.3645 -      rules = [Thm ("rat_mult",num_str rat_mult),
  1.3646 -	       (*"?a / ?b * (?c / ?d) = ?a * ?c / (?b * ?d)"*)
  1.3647 -	       Thm ("rat_mult_poly_l",num_str rat_mult_poly_l),
  1.3648 -	       (*"?c is_polyexp ==> ?c * (?a / ?b) = ?c * ?a / ?b"*)
  1.3649 -	       Thm ("rat_mult_poly_r",num_str rat_mult_poly_r),
  1.3650 -	       (*"?c is_polyexp ==> ?a / ?b * ?c = ?a * ?c / ?b"*)
  1.3651 -
  1.3652 -	       Thm ("real_divide_divide1_mg", real_divide_divide1_mg),
  1.3653 -	       (*"y ~= 0 ==> (u / v) / (y / z) = (u * z) / (y * v)"*)
  1.3654 -	       Thm ("real_divide_divide1_eq", real_divide_divide1_eq),
  1.3655 -	       (*"?x / (?y / ?z) = ?x * ?z / ?y"*)
  1.3656 -	       Thm ("real_divide_divide2_eq", real_divide_divide2_eq),
  1.3657 -	       (*"?x / ?y / ?z = ?x / (?y * ?z)"*)
  1.3658 -	       Calc ("HOL.divide"  ,eval_cancel "#divide_"),
  1.3659 -	      
  1.3660 -	       Thm ("rat_power", num_str rat_power)
  1.3661 -		(*"(?a / ?b) ^^^ ?n = ?a ^^^ ?n / ?b ^^^ ?n"*)
  1.3662 -	       ],
  1.3663 -      scr = Script ((term_of o the o (parse thy)) "empty_script")
  1.3664 -      }:rls);
  1.3665 -(* ------------------------------------------------------------------ *)
  1.3666 -val rat_reduce_1 = prep_rls(
  1.3667 -  Rls {id = "rat_reduce_1", preconds = [], 
  1.3668 -       rew_ord = ("dummy_ord",dummy_ord), 
  1.3669 -       erls = e_rls, srls = Erls, calc = [], 
  1.3670 -       rules = [Thm ("real_divide_1",num_str real_divide_1),
  1.3671 -		(*"?x / 1 = ?x"*)
  1.3672 -		Thm ("real_mult_1",num_str real_mult_1)           
  1.3673 -		(*"1 * z = z"*)
  1.3674 -		],
  1.3675 -       scr = Script ((term_of o the o (parse thy)) "empty_script")
  1.3676 -       }:rls);
  1.3677 -(* ------------------------------------------------------------------ *)
  1.3678 -(*. looping part of norm_Rational(*_mg*) .*)
  1.3679 -val norm_Rational_rls = prep_rls(
  1.3680 -   Rls {id = "norm_Rational_rls", preconds = [], 
  1.3681 -       rew_ord = ("dummy_ord",dummy_ord), 
  1.3682 -       erls = norm_rat_erls, srls = Erls, calc = [],
  1.3683 -       rules = [Rls_ common_nominator_p_rls,
  1.3684 -		Rls_ rat_mult_div_pow,
  1.3685 -		Rls_ make_rat_poly_with_parentheses,
  1.3686 -		Rls_ cancel_p_rls,(*FIXME:cancel_p does NOT order sometimes*)
  1.3687 -		Rls_ rat_reduce_1
  1.3688 -		],
  1.3689 -       scr = Script ((term_of o the o (parse thy)) "empty_script")
  1.3690 -       }:rls);
  1.3691 -(* ------------------------------------------------------------------ *)
  1.3692 -(*040109 'norm_Rational'(by RL) replaced by 'norm_Rational_mg'(MG)
  1.3693 - just be renaming:*)
  1.3694 -val norm_Rational(*_mg*) = prep_rls(
  1.3695 -   Seq {id = "norm_Rational"(*_mg*), preconds = [], 
  1.3696 -       rew_ord = ("dummy_ord",dummy_ord), 
  1.3697 -       erls = norm_rat_erls, srls = Erls, calc = [],
  1.3698 -       rules = [Rls_ discard_minus_,
  1.3699 -		Rls_ rat_mult_poly,(* removes double fractions like a/b/c    *)
  1.3700 -		Rls_ make_rat_poly_with_parentheses, (*WN0510 also in(#)below*)
  1.3701 -		Rls_ cancel_p_rls, (*FIXME.MG:cancel_p does NOT order sometim*)
  1.3702 -		Rls_ norm_Rational_rls,   (* the main rls, looping (#)       *)
  1.3703 -		Rls_ discard_parentheses_ (* mult only                       *)
  1.3704 -		],
  1.3705 -       scr = Script ((term_of o the o (parse thy)) "empty_script")
  1.3706 -       }:rls);
  1.3707 -(* ------------------------------------------------------------------ *)
  1.3708 -
  1.3709 -
  1.3710 -ruleset' := overwritelthy thy (!ruleset',
  1.3711 -  [("calculate_Rational", calculate_Rational),
  1.3712 -   ("calc_rat_erls",calc_rat_erls),
  1.3713 -   ("rational_erls", rational_erls),
  1.3714 -   ("cancel_p", cancel_p),
  1.3715 -   ("cancel", cancel),
  1.3716 -   ("common_nominator_p", common_nominator_p),
  1.3717 -   ("common_nominator_p_rls", common_nominator_p_rls),
  1.3718 -   ("common_nominator"  , common_nominator),
  1.3719 -   ("discard_minus", discard_minus),
  1.3720 -   ("powers_erls", powers_erls),
  1.3721 -   ("powers", powers),
  1.3722 -   ("rat_mult_divide", rat_mult_divide),
  1.3723 -   ("reduce_0_1_2", reduce_0_1_2),
  1.3724 -   ("rat_reduce_1", rat_reduce_1),
  1.3725 -   ("norm_rat_erls", norm_rat_erls),
  1.3726 -   ("norm_Rational", norm_Rational),
  1.3727 -   ("norm_Rational_rls", norm_Rational_rls),
  1.3728 -   ("norm_Rational_parenthesized", norm_Rational_parenthesized),
  1.3729 -   ("rat_mult_poly", rat_mult_poly),
  1.3730 -   ("rat_mult_div_pow", rat_mult_div_pow),
  1.3731 -   ("cancel_p_rls", cancel_p_rls)
  1.3732 -   ]);
  1.3733 -
  1.3734 -calclist':= overwritel (!calclist', 
  1.3735 -   [("is_expanded", ("Rational.is'_expanded", eval_is_expanded ""))
  1.3736 -    ]);
  1.3737 -
  1.3738 -(** problems **)
  1.3739 -
  1.3740 -store_pbt
  1.3741 - (prep_pbt Rational.thy "pbl_simp_rat" [] e_pblID
  1.3742 - (["rational","simplification"],
  1.3743 -  [("#Given" ,["term t_"]),
  1.3744 -   ("#Where" ,["t_ is_ratpolyexp"]),
  1.3745 -   ("#Find"  ,["normalform n_"])
  1.3746 -  ],
  1.3747 -  append_rls "e_rls" e_rls [(*for preds in where_*)], 
  1.3748 -  SOME "Simplify t_", 
  1.3749 -  [["simplification","of_rationals"]]));
  1.3750 -
  1.3751 -(** methods **)
  1.3752 -
  1.3753 -(*WN061025 this methods script is copied from (auto-generated) script
  1.3754 -  of norm_Rational in order to ease repair on inform*)
  1.3755 -store_met
  1.3756 -    (prep_met Rational.thy "met_simp_rat" [] e_metID
  1.3757 -	      (["simplification","of_rationals"],
  1.3758 -	       [("#Given" ,["term t_"]),
  1.3759 -		("#Where" ,["t_ is_ratpolyexp"]),
  1.3760 -		("#Find"  ,["normalform n_"])
  1.3761 -		],
  1.3762 -	       {rew_ord'="tless_true",
  1.3763 -		rls' = e_rls,
  1.3764 -		calc = [], srls = e_rls, 
  1.3765 -		prls = append_rls "simplification_of_rationals_prls" e_rls 
  1.3766 -				[(*for preds in where_*)
  1.3767 -				 Calc ("Rational.is'_ratpolyexp", 
  1.3768 -				       eval_is_ratpolyexp "")],
  1.3769 -		crls = e_rls, nrls = norm_Rational_rls},
  1.3770 -"Script SimplifyScript (t_::real) =                              \
  1.3771 -\  ((Try (Rewrite_Set discard_minus_ False) @@                   \
  1.3772 -\    Try (Rewrite_Set rat_mult_poly False) @@                    \
  1.3773 -\    Try (Rewrite_Set make_rat_poly_with_parentheses False) @@   \
  1.3774 -\    Try (Rewrite_Set cancel_p_rls False) @@                     \
  1.3775 -\    (Repeat                                                     \
  1.3776 -\     ((Try (Rewrite_Set common_nominator_p_rls False) @@        \
  1.3777 -\       Try (Rewrite_Set rat_mult_div_pow False) @@              \
  1.3778 -\       Try (Rewrite_Set make_rat_poly_with_parentheses False) @@\
  1.3779 -\       Try (Rewrite_Set cancel_p_rls False) @@                  \
  1.3780 -\       Try (Rewrite_Set rat_reduce_1 False)))) @@               \
  1.3781 -\    Try (Rewrite_Set discard_parentheses_ False))               \
  1.3782 -\    t_)"
  1.3783 -	       ));
  1.3784 -
  1.3785 -(* use"../IsacKnowledge/Rational.ML";
  1.3786 -   use"IsacKnowledge/Rational.ML";
  1.3787 -   use"Rational.ML";
  1.3788 -   *)
  1.3789 -