test/Tools/isac/Knowledge/rational.sml
author Walther Neuper <neuper@ist.tugraz.at>
Mon, 16 Sep 2013 12:20:00 +0200
changeset 52105 2786cc9704c8
parent 52104 83166e7c7e52
child 52106 7f3760f39bdc
permissions -rw-r--r--
Test_Isac works again, perfectly ..

# the same tests works as in 8df4b6196660 (the *child* of "Test_Isac works...")
# ..EXCEPT those marked with "exception Div raised"
# for general state of tests see Test_Isac section {* history of tests *}.
     1 (* Title: tests for rationals
     2    Author: Walther Neuper
     3    Use is subject to license terms.
     4 *)
     5 
     6 "-----------------------------------------------------------------------------";
     7 "-----------------------------------------------------------------------------";
     8 "table of contents -----------------------------------------------------------";
     9 "-----------------------------------------------------------------------------";
    10 "-------- fun poly_of_term ---------------------------------------------------";
    11 "-------- fun is_poly --------------------------------------------------------";
    12 "-------- fun term_of_poly ---------------------------------------------------";
    13 "-------- integration lev.1 fun factout_p_ -----------------------------------";
    14 "-------- integration lev.1 fun cancel_p_ ------------------------------------";
    15 "-------- integration lev.1 fun common_nominator_p_ --------------------------";
    16 "-------- integration lev.1 fun add_fraction_p_ ------------------------------";
    17 "-------- and app_rev ...traced down from rewrite_set_ until prepats ---------";
    18 "-------- fun rewrite_set_ cancel_p downto fun gcd_poly ----------------------";
    19 "-------- rls norm_Rational downto fun gcd_poly ------------------------------";
    20 "-------- rls norm_Rational downto fun add_fraction_p_ -----------------------";
    21 "-------- rewrite_set_ cancel_p from: Mathematik 1 Schalk Reniets Verlag -----";
    22 "-------- rewrite_set_ add_fractions_p from: Mathematik 1 Schalk -------------";
    23 "-------- integration lev.1 -- lev.5: cancel_p_ & add_fractions_p_ -----------";
    24 "-------- reverse rewrite ----------------------------------------------------";
    25 "-------- 'reverse-ruleset' cancel_p -----------------------------------------";
    26 "-------- investigate rls norm_Rational --------------------------------------";
    27 "-------- examples: rls norm_Rational ----------------------------------------";
    28 "-------- rational numerals --------------------------------------------------";
    29 "-------- examples cancellation from: Mathematik 1 Schalk --------------------";
    30 "-------- examples common denominator from: Mathematik 1 Schalk --------------";
    31 "-------- examples multiply and cancel from: Mathematik 1 Schalk -------------";
    32 "-------- examples common denominator and multiplication from: Schalk --------";
    33 "-------- examples double fractions from: Mathematik 1 Schalk ----------------";
    34 "-------- me Schalk I No.186 -------------------------------------------------";
    35 "-------- interSteps ..Simp_Rat_Double_No-1.xml ------------------------------";
    36 "-------- interSteps ..Simp_Rat_Cancel_No-1.xml ------------------------------";
    37 "-------- investigate rulesets for cancel_p ----------------------------------";
    38 "-------- fun eval_get_denominator -------------------------------------------";
    39 "-------- several errpats in complicated term --------------------------------";
    40 "-----------------------------------------------------------------------------";
    41 "-----------------------------------------------------------------------------";
    42 
    43 
    44 "-------- fun poly_of_term ---------------------------------------------------";
    45 "-------- fun poly_of_term ---------------------------------------------------";
    46 "-------- fun poly_of_term ---------------------------------------------------";
    47 val vs = "12 * x^^^3 * y^^^4 * z^^^6" |> str2term |> vars |> map free2str |> sort string_ord;
    48 
    49 if poly_of_term vs (str2term "12::real") = SOME [(12, [0, 0, 0])]
    50 then () else error "poly_of_term 1 changed";
    51 if poly_of_term vs (str2term "x::real") = SOME [(1, [1, 0, 0])]
    52 then () else error "poly_of_term 2 changed";
    53 if poly_of_term vs (str2term "12 * x^^^3") = SOME [(12, [3, 0, 0])]
    54 then () else error "poly_of_term 3 changed";
    55 if poly_of_term vs (str2term "12 * x^^^3 * y^^^4 * z^^^6") = SOME [(12, [3, 4, 6])]
    56 then () else error "poly_of_term 4 changed";
    57 if poly_of_term vs (str2term "1 + 2 * x^^^3 * y^^^4 * z^^^6 + y") =
    58   SOME [(1, [0, 0, 0]), (1, [0, 1, 0]), (2, [3, 4, 6])]
    59 then () else error "poly_of_term 5 changed";
    60 
    61 (*poly_of_term is quite liberal:*)
    62 (*the coefficient may be somewhere, the order of variables and the parentheses 
    63   within a monomial are arbitrary*)
    64 if poly_of_term vs (str2term "y^^^4 * (x^^^3 * 12 * z^^^6)") = SOME [(12, [3, 4, 6])]
    65 then () else error "poly_of_term 6 changed";
    66 
    67 (*there may even be more than 1 coefficient:*)
    68 if poly_of_term vs (str2term "2 * y^^^4 * (x^^^3 * 6 * z^^^6)") = SOME [(12, [3, 4, 6])]
    69 then () else error "poly_of_term 7 changed";
    70 
    71 (*the order and the parentheses within monomials are arbitrary:*)
    72 if poly_of_term vs (str2term "2 * x^^^3 * y^^^4 * z^^^6 + (7 * y^^^8 + 1)")
    73   = SOME [(1, [0, 0, 0]), (7, [0, 8, 0]), (2, [3, 4, 6])]
    74 then () else error "poly_of_term 8 changed";
    75 
    76 "-------- fun is_poly --------------------------------------------------------";
    77 "-------- fun is_poly --------------------------------------------------------";
    78 "-------- fun is_poly --------------------------------------------------------";
    79 if is_poly (str2term "2 * x^^^3 * y^^^4 * z^^^6 + 7 * y^^^8 + 1")
    80 then () else error "is_poly 1 changed";
    81 if not (is_poly (str2term "2 * (x^^^3 * y^^^4 * z^^^6 + 7) * y^^^8 + 1"))
    82 then () else error "is_poly 2 changed";
    83 
    84 "-------- fun term_of_poly ---------------------------------------------------";
    85 "-------- fun term_of_poly ---------------------------------------------------";
    86 "-------- fun term_of_poly ---------------------------------------------------";
    87 val expT = HOLogic.realT
    88 val Free (_, baseT) = (hd o vars o str2term) "12 * x^^^3 * y^^^4 * z^^^6";
    89 val p = [(1, [0, 0, 0]), (7, [0, 8, 0]), (2, [3, 4, 5])]
    90 val vs = ["x","y","z"]
    91 (*precondition for [(c, es),...]: legth es = length vs*)
    92 ;
    93 if term2str (term_of_poly baseT expT vs p) = "1 + 7 * y ^^^ 8 + 2 * x ^^^ 3 * y ^^^ 4 * z ^^^ 5"
    94 then () else error "term_of_poly 1 changed";
    95 
    96 "-------- integration lev.1 fun factout_p_ -----------------------------------";
    97 "-------- integration lev.1 fun factout_p_ -----------------------------------";
    98 "-------- integration lev.1 fun factout_p_ -----------------------------------";
    99 val t = str2term "(x^^^2 + -1*y^^^2) / (x^^^2 + -1*x*y)"
   100 val SOME (t', asm) = factout_p_ thy t;
   101 if term2str t' = "(x + y) * (x + -1 * y) / (x * (x + -1 * y))"
   102 then () else error ("factout_p_ term 1 changed: " ^ term2str t')
   103 ;
   104 if terms2str asm = "[\"x ~= 0\",\"x + -1 * y ~= 0\"]"
   105 then () else error "factout_p_ asm 1 changed"
   106 ;
   107 val t = str2term "nothing + to_cancel ::real";
   108 if NONE = factout_p_ thy t then () else error "factout_p_ doesn't report non-applicable";
   109 ;
   110 val t = str2term "((3 * x^^^2 + 6 *x + 3) / (2*x + 2))";
   111 val SOME (t', asm) = factout_p_ thy t;
   112 if term2str t' = "(3 + 3 * x) * (1 + x) / (2 * (1 + x))" andalso 
   113   terms2str asm = "[\"1 + x ~= 0\"]"
   114 then () else error "factout_p_ 1 changed";
   115 
   116 "-------- integration lev.1 fun cancel_p_ ------------------------------------";
   117 "-------- integration lev.1 fun cancel_p_ ------------------------------------";
   118 "-------- integration lev.1 fun cancel_p_ ------------------------------------";
   119 val t = str2term "(x^^^2 + -1*y^^^2) / (x^^^2 + -1*x*y)"
   120 val SOME (t', asm) = cancel_p_ thy t;
   121 if (term2str t', terms2str asm) = ("(x + y) / x", "[\"x ~= 0\"]")
   122 then () else error ("cancel_p_ (t', asm) 1 changed: " ^ term2str t')
   123 ;
   124 val t = str2term "nothing + to_cancel ::real";
   125 if NONE = cancel_p_ thy t then () else error "cancel_p_ doesn't report non-applicable";
   126 ;
   127 val t = str2term "((3 * x^^^2 + 6 *x + 3) / (2*x + 2))";
   128 val SOME (t', asm) = cancel_p_ thy t;
   129 if term2str t' = "(3 + 3 * x) / 2" andalso terms2str asm = "[]"
   130 then () else error "cancel_p_ 1 changed";
   131 
   132 "-------- integration lev.1 fun common_nominator_p_ --------------------------";
   133 "-------- integration lev.1 fun common_nominator_p_ --------------------------";
   134 "-------- integration lev.1 fun common_nominator_p_ --------------------------";
   135 val t = str2term ("y / (a*x + b*x + c*x) " ^
   136               (* n1    d1                   *)
   137                 "+ a / (x*y)");
   138               (* n2    d2                   *)
   139 val SOME (t', asm) = common_nominator_p_ thy t;
   140 if term2str t' =
   141       ("y * y / (x * ((a + b + c) * y)) " ^
   142   (*  n1  *d2'/ (c'* ( d1'        *d2')) *)
   143      "+ a * (a + b + c) / (x * ((a + b + c) * y))")
   144    (*  n2 * d1'         / (c'* ( d1'        *d2')) *)
   145 then () else error "common_nominator_p_ term 1 changed";
   146 if terms2str asm = "[\"a + b + c ~= 0\",\"y ~= 0\",\"x ~= 0\"]"
   147 then () else error "common_nominator_p_ asm 1 changed"
   148 
   149 "-------- example in mail Nipkow";
   150 val t = str2term "x/(x^^^2 + -1*y^^^2) + y/(x^^^2 + -1*x*y)";
   151 val SOME (t', asm) = common_nominator_p_ thy t;
   152 if term2str t' = "x * x / " ^ 
   153                  "((x + -1 * y) * ((x + y) * x))" ^
   154             " +\n" ^ 
   155                  "y * (x + y) / " ^ 
   156                  "((x + -1 * y) * ((x + y) * x))"
   157 then () else error "common_nominator_p_ term 2 changed"
   158 ;
   159 if terms2str asm = "[\"x + y ~= 0\",\"x ~= 0\",\"x + -1 * y ~= 0\"]"
   160 then () else error "common_nominator_p_ asm 2 changed"
   161 
   162 "-------- example: applicable tested by SML code";
   163 val t = str2term "nothing / to_add";
   164 if NONE = common_nominator_p_ thy t then () else error "common_nominator_p_ term 3 changed";
   165 ;
   166 val t = str2term "((x + (-1)) / (x + 1)) + ((x + 1) / (x + (-1)))";
   167 val SOME (t', asm) = common_nominator_p_ thy t;
   168 if term2str t' = 
   169    "(x + -1) * (-1 + x) / ((1 + x) * (-1 + x)) +\n(x + 1) * (1 + x) / ((1 + x) * (-1 + x))"
   170   andalso terms2str asm = "[\"1 + x ~= 0\",\"-1 + x ~= 0\"]"
   171 then () else error "common_nominator_p_ 3 changed";
   172 
   173 "-------- integration lev.1 fun add_fraction_p_ ------------------------------";
   174 "-------- integration lev.1 fun add_fraction_p_ ------------------------------";
   175 "-------- integration lev.1 fun add_fraction_p_ ------------------------------";
   176 val t = str2term "((x + (-1)) / (x + 1)) + ((x + 1) / (x + (-1)))";
   177 val SOME (t', asm) = add_fraction_p_ thy t;
   178 if term2str t' = "(2 + 2 * x ^^^ 2) / (-1 + x ^^^ 2)" 
   179 then () else error "add_fraction_p_ 3 changed";
   180 ;
   181 if terms2str asm = "[\"-1 + x ^^^ 2 ~= 0\"]"
   182 then () else error "add_fraction_p_ 3 changed";
   183 ;
   184 val t = str2term "nothing / to_add";
   185 if NONE = add_fraction_p_ thy t then () else error "add_fraction_p_ term 3 changed";
   186 ;
   187 val t = str2term "((x + (-1)) / (x + 1)) + ((x + 1) / (x + (-1)))";
   188 val SOME (t', asm) = add_fraction_p_ thy t;
   189 if term2str t' = "(2 + 2 * x ^^^ 2) / (-1 + x ^^^ 2)" andalso
   190   terms2str asm = "[\"-1 + x ^^^ 2 ~= 0\"]"
   191 then () else error "add_fraction_p_ 3 changed";
   192 
   193 "-------- and app_rev ...traced down from rewrite_set_ until prepats ---------";
   194 "-------- and app_rev ...traced down from rewrite_set_ until prepats ---------";
   195 "-------- and app_rev ...traced down from rewrite_set_ until prepats ---------";
   196 (* trace down until prepats are evaluated 
   197   (which does not to work, because substitution is not done -- compare rew_sub!);
   198   keep this sequence for the case, factout_p, cancel_p, common_nominator_p, add_fraction_p
   199   (again) get prepat = [] changed to <>[]. *)
   200 val t = str2term "(x^^^2 + -1*y^^^2) / (x^^^2 + -1*x*y)";
   201 
   202 (*rewrite_set_ @{theory Isac} true cancel t = NONE; !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!*)
   203 "~~~~~ fun rewrite_set_, args:"; val (thy, bool, rls, term) = (thy, false, cancel_p, t);
   204 "~~~~~ fun rewrite__set_, args:"; val (thy, i, _, _, (rrls as Rrls _), t) =
   205   (thy, 1, bool, [], rls, term);
   206 (*val (t', asm, rew) = app_rev thy (i+1) rrls t; rew = false!!!!!!!!!!!!!!!!!!!!!*)
   207 "~~~~~ and app_rev, args:"; val (thy, i, rrls, t) = (thy, (i+1), rrls, t);
   208     fun chk_prepat thy erls [] t = true
   209       | chk_prepat thy erls prepat t =
   210         let
   211           fun chk (pres, pat) =
   212             (let 
   213               val subst: Type.tyenv * Envir.tenv =
   214                 Pattern.match thy (pat, t) (Vartab.empty, Vartab.empty)
   215              in
   216               snd (eval__true thy (i + 1) (map (Envir.subst_term subst) pres) [] erls)
   217              end) handle _ => false
   218            fun scan_ f [] = false (*scan_ NEVER called by []*)
   219              | scan_ f (pp::pps) =
   220                if f pp then true else scan_ f pps;
   221         in scan_ chk prepat end;
   222     (* apply the normal_form of a rev-set *)
   223     fun app_rev' thy (Rrls{erls,prepat,scr=Rfuns{normal_form,...},...}) t =
   224       if chk_prepat thy erls prepat t
   225       then ((*tracing("### app_rev': t = "^term2str t);*) normal_form t)
   226       else NONE;
   227 (*  val opt = app_rev' thy rrls t  ..NONE!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!*)
   228 "~~~~~ and app_rev', args:"; val (thy, (Rrls{erls,prepat,scr=Rfuns{normal_form,...},...}), t) =
   229   (thy, rrls, t);
   230 (* chk_prepat thy erls prepat t = false!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!*)
   231 (* app_sub thy i rrls t = false!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!*)
   232 "~~~~~ fun chk_prepat, args:"; val (thy, erls, prepat, t) = (thy, erls, prepat, t);
   233           fun chk (pres, pat) =
   234             (let 
   235               val subst: Type.tyenv * Envir.tenv =
   236                 Pattern.match thy (pat, t) (Vartab.empty, Vartab.empty)
   237              in
   238               snd (eval__true thy (i + 1) (map (Envir.subst_term subst) pres) [] erls)
   239              end) handle _ => false
   240            fun scan_ f [] = false (*scan_ NEVER called by []*)
   241              | scan_ f (pp::pps) =
   242                if f pp then true else scan_ f pps;
   243 
   244 (*========== inhibit exn WN130823: prepat is empty ====================================
   245 (* scan_ chk prepat = false!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!*)
   246 "~~~~~ fun , args:"; val (f, (pp::pps)) = (chk, prepat);
   247 f;
   248 val ([t1, t2], t) = pp;
   249 term2str t1 = "?r is_expanded";
   250 term2str t2 = "?s is_expanded";
   251 term2str t = "?r / ?s";
   252 (* f pp = false!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!*)
   253 "~~~~~ fun chk, args:"; val (pres, pat) = (pp);
   254               val subst: Type.tyenv * Envir.tenv =
   255                 Pattern.match thy (pat, t) (Vartab.empty, Vartab.empty)
   256 (*subst = 
   257   ({}, {(("r", 0), ("real", Var (("r", 0), "real"))), 
   258         (("s", 0), ("real", Var (("s", 0), "real")))}*)
   259 ;
   260               snd (eval__true thy (i + 1) (map (Envir.subst_term subst) pres) [] erls)
   261 "~~~~~ fun eval__true, args:"; val (thy, i, asms, bdv, rls) =
   262   (thy, (i + 1), (map (Envir.subst_term subst) pres), [], erls);
   263 terms2str asms;                         (* = "[\"?r is_expanded\",\"?s is_expanded\"]"*)
   264 asms = [@{term True}] orelse asms = []; (* = false*)
   265 asms = [@{term False}]                ; (* = false*)
   266 "~~~~~ fun chk, args:"; val (indets, (a::asms)) = ([], asms);
   267 bdv (*= []: _a list*);
   268 val bdv : (term * term) list = [];
   269 rewrite__set_ thy (i+1) false;
   270 term2str a = "?r is_expanded"; (*hier m"usste doch der Numerator eingesetzt sein ??????????????*)
   271 val SOME (Const ("HOL.False", _), []) = rewrite__set_ thy (i+1) false bdv rls a
   272 ============ inhibit exn WN130823: prepat is empty ===================================*)
   273 
   274 "-------- fun rewrite_set_ cancel_p downto fun gcd_poly ----------------------";
   275 "-------- fun rewrite_set_ cancel_p downto fun gcd_poly ----------------------";
   276 "-------- fun rewrite_set_ cancel_p downto fun gcd_poly ----------------------";
   277 val t = str2term "(12 * x * y) / (8 * y^^^2 )";
   278 (* "-------- example 187a": exception Div raised...
   279 val SOME (t', asm) = rewrite_set_ thy false cancel_p t;*)
   280 val t = str2term "(8 * x^^^2 * y * z ) / (18 * x * y^^^2 * z )";
   281 (* "-------- example 187b": doesn't terminate...
   282 val SOME (t', asm) = rewrite_set_ thy false cancel_p t;*)
   283 val t = str2term "(9 * x^^^5 * y^^^2 * z^^^4) / (15 * x^^^6 * y^^^3 * z )";
   284 (* "-------- example 187c": doesn't terminate...
   285 val SOME (t', asm) = rewrite_set_ thy false cancel_p t;*)
   286 "~~~~~ fun rewrite_set_, args:"; val (thy, bool, rls, term) = (@{theory Isac}, false, cancel_p, t);
   287 (* WN130827: exception Div raised...
   288 rewrite__set_ thy 1 bool [] rls term
   289 *)
   290 "~~~~~ and rewrite__set_, args:"; val (thy, i, _, _, (rrls as Rrls _), t) =
   291   (thy, 1, bool, [], rls, term);
   292 (* WN130827: exception Div raised...
   293 	val (t', asm, rew) = app_rev thy (i+1) rrls t
   294 *)
   295 "~~~~~ fun app_rev, args:"; val (thy, i, rrls, t) = (thy, (i+1), rrls, t);
   296 (* WN130827: exception Div raised...
   297     val opt = app_rev' thy rrls t
   298 *)
   299 "~~~~~ fun app_rev', args:"; val (thy, (Rrls{erls,prepat,scr=Rfuns{normal_form,...},...}), t) =
   300   (thy, rrls, t);
   301 chk_prepat thy erls prepat t    = true;
   302 (* WN130827: exception Div raised...
   303 normal_form t
   304 *)
   305 (* lookup Rational.thy, cancel_p: normal_form = cancel_p_ thy*)
   306 "~~~~~ fun cancel_p_, args:"; val (t) = (t);
   307 val opt = check_fraction t;
   308 val SOME (numerator, denominator) = opt
   309         val vs = t |> vars |> map free2str |> sort string_ord
   310         val baseT = type_of numerator
   311         val expT = HOLogic.realT
   312 val (SOME a, SOME b) = (poly_of_term vs numerator, poly_of_term vs denominator);
   313 (*"-------- example 187a": exception Div raised...
   314 val a = [(12, [1, 1])]: poly
   315 val b = [(8, [0, 2])]: poly
   316               val ((a', b'), c) = gcd_poly a b
   317 *)
   318 (* "-------- example 187b": doesn't terminate...
   319 val a = [(8, [2, 1, 1])]: poly
   320 val b = [(18, [1, 2, 1])]: poly
   321               val ((a', b'), c) = gcd_poly a b
   322 *)
   323 (* "-------- example 187c": doesn't terminate...
   324 val a = [(9, [5, 2, 4])]: poly
   325 val b = [(15, [6, 3, 1])]: poly
   326               val ((a', b'), c) = gcd_poly a b
   327 *)
   328 
   329 "-------- rls norm_Rational downto fun gcd_poly ------------------------------";
   330 "-------- rls norm_Rational downto fun gcd_poly ------------------------------";
   331 "-------- rls norm_Rational downto fun gcd_poly ------------------------------";
   332 val t = str2term "(x^^^2 - 4)*(3 - y) / ((y^^^2 - 9)*(2+x))";
   333 trace_rewrite := false (*true false*);
   334 (* trace stops with ...: (and then jEdit hangs)..
   335 rewrite_set_ thy false norm_Rational t;
   336 :
   337 ###  rls: cancel_p on: (-12 + 4 * y + 3 * x ^^^ 2 + -1 * (x ^^^ 2 * y)) /
   338 (-18 + -9 * x + 2 * y ^^^ 2 + x * y ^^^ 2)
   339 *)
   340 val t = str2term (*copy from above: "::real" is not required due to "^^^"*)
   341   ("(-12 + 4 * y + 3 * x ^^^ 2 + -1 * (x ^^^ 2 * y)) /" ^
   342   "(-18 + -9 * x + 2 * y ^^^ 2 + x * y ^^^ 2)");
   343 (*cancel_p_ thy t;
   344 exception Div raised*)
   345 
   346 "~~~~~ fun cancel_p_, args:"; val (t) = (t);
   347 val opt = check_fraction t;
   348 val SOME (numerator, denominator) = opt
   349         val vs = t |> vars |> map free2str |> sort string_ord
   350         val baseT = type_of numerator
   351         val expT = HOLogic.realT;
   352 print_depth 3; (*999*)
   353 val (SOME a, SOME b) = (poly_of_term vs numerator, poly_of_term vs denominator);
   354 print_depth 3; (*999*)
   355 (* does not terminate instead of returning ?:
   356         val ((a', b'), c) = gcd_poly a b
   357 val a = [(~12, [0, 0]), (3, [2, 0]), (4, [0, 1]), (~1, [2, 1])]: poly
   358 val b = [(~18, [0, 0]), (~9, [1, 0]), (2, [0, 2]), (1, [1, 2])]: poly
   359 *)
   360 
   361 "-------- rls norm_Rational downto fun add_fraction_p_ -----------------------";
   362 "-------- rls norm_Rational downto fun add_fraction_p_ -----------------------";
   363 "-------- rls norm_Rational downto fun add_fraction_p_ -----------------------";
   364 val thy =  @{theory Isac};
   365 "----- SK060904-2a non-termination of add_fraction_p_";
   366 val t = str2term (" (a + b * x) / (a + -1 * (b * x)) +  " ^
   367 		         " (-1 * a + b * x) / (a + b * x)      ");
   368 (* rewrite_set_ thy false norm_Rational t
   369 exception Div raised*)
   370 (* rewrite_set_ thy false add_fractions_p t;
   371 exception Div raised*)
   372 "~~~~~ fun rewrite_set_, args:"; val (thy, bool, rls, term) =
   373   (@{theory Isac}, false, add_fractions_p, t);
   374 "~~~~~ and rewrite__set_, args:"; val (thy, i, _, _, (rrls as Rrls _), t) =
   375   (thy, 1, bool, [], rls, term);
   376 (* app_rev thy (i+1) rrls t;
   377 exception Div raised*)
   378 "~~~~~ and app_rev, args:"; val (thy, i, rrls, t) = (thy, (i+1), rrls, t);
   379     fun chk_prepat thy erls [] t = true
   380       | chk_prepat thy erls prepat t =
   381         let
   382           fun chk (pres, pat) =
   383             (let 
   384               val subst: Type.tyenv * Envir.tenv =
   385                 Pattern.match thy (pat, t) (Vartab.empty, Vartab.empty)
   386              in
   387               snd (eval__true thy (i + 1) (map (Envir.subst_term subst) pres) [] erls)
   388              end) handle _ => false
   389            fun scan_ f [] = false (*scan_ NEVER called by []*)
   390              | scan_ f (pp::pps) =
   391                if f pp then true else scan_ f pps;
   392         in scan_ chk prepat end;
   393     (* apply the normal_form of a rev-set *)
   394     fun app_rev' thy (Rrls{erls,prepat,scr=Rfuns{normal_form,...},...}) t =
   395       if chk_prepat thy erls prepat t
   396       then ((*tracing("### app_rev': t = "^term2str t);*) normal_form t)
   397       else NONE;
   398 (*  val opt = app_rev' thy rrls t;
   399 exception Div raised*)
   400 (*  val opt = app_rev' thy rrls t;
   401 exception Div raised*)
   402 "~~~~~ and app_rev', args:"; val (thy, (Rrls{erls,prepat,scr=Rfuns{normal_form,...},...}), t) =
   403   (thy, rrls, t);
   404 chk_prepat thy erls prepat t = true       = true;
   405 (*normal_form t
   406 exception Div raised*)
   407 (* lookup Rational.thy, val add_fractions_p: normal_form = add_fraction_p_ thy*)
   408 (*add_fraction_p_ thy t
   409 exception Div raised*)
   410 "~~~~~ fun add_fraction_p_, args:"; val ((_: theory), t) = (thy, t);
   411 val SOME ((n1, d1), (n2, d2)) = check_frac_sum t;
   412 term2str n1; term2str d1; term2str n2; term2str d2;
   413       val vs = t |> vars |> map str_of_free_opt (* tolerate Var in simplification *)
   414         |> filter is_some |> map the |> sort string_ord;
   415 print_depth 3; (*999*)
   416 val (SOME _, SOME a, SOME _, SOME b) =
   417   (poly_of_term vs n1, poly_of_term vs d1, poly_of_term vs n2, poly_of_term vs d2);
   418 print_depth 3; (*999*)
   419 (*
   420 val a = [(1, [1, 0, 0]), (~1, [0, 1, 1])]: poly
   421 val b = [(1, [1, 0, 0]), (1, [0, 1, 1])]: poly
   422             val ((a', b'), c) = gcd_poly a b
   423 *)
   424 
   425 "-------- rewrite_set_ cancel_p from: Mathematik 1 Schalk Reniets Verlag -----";
   426 "-------- rewrite_set_ cancel_p from: Mathematik 1 Schalk Reniets Verlag -----";
   427 "-------- rewrite_set_ cancel_p from: Mathematik 1 Schalk Reniets Verlag -----";
   428 val thy  = @{theory "Rational"};
   429 "-------- WN";
   430 val t = str2term "(2 + -3 * x) / 9";
   431 if NONE = rewrite_set_ thy false cancel_p t then ()
   432 else error "rewrite_set_ cancel_p must return NONE, if the term cannot be cancelled";
   433 
   434 "-------- example 186a";
   435 val t = str2term "(14 * x * y) / (x * y)";
   436   is_expanded (str2term "14 * x * y");
   437   is_expanded (str2term "x * y");
   438 val SOME (t', asm) = rewrite_set_ thy false cancel_p t;
   439 if (term2str t', terms2str asm) = ("14 / 1", "[]")
   440 then () else error "rational.sml cancel Schalk 186a";
   441 
   442 "-------- example 186b";
   443 val t = str2term "(60 * a * b) / ( 15 * a  * b )";
   444 val SOME (t', asm) = rewrite_set_ thy false cancel_p t;
   445 if (term2str t', terms2str asm) = ("4 / 1", "[]")
   446 then () else error "rational.sml cancel Schalk 186b";
   447 
   448 "-------- example 186c";
   449 val t = str2term "(144 * a^^^2 * b * c) / (12 * a * b * c)";
   450 val SOME (t', asm) = rewrite_set_ thy false cancel_p t;
   451 if (term2str t', terms2str asm) = ("12 * a / 1", "[]")
   452 then () else error "rational.sml cancel Schalk 186c";
   453 
   454 (* !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! exception Div raised !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
   455   see --- fun rewrite_set_ downto fun gcd_poly ---
   456 "-------- example 187a";
   457 val t = str2term "(12 * x * y) / (8 * y^^^2 )";
   458 val SOME (t', asm) = rewrite_set_ thy false cancel_p t;
   459 if (term2str t', terms2str asm) = ("3 * x / (2 * y)", "[\"4 * y ~= 0\"]")
   460 then () else error "rational.sml cancel Schalk 187a";
   461 *)
   462 
   463 (* doesn't terminate !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
   464   see --- fun rewrite_set_ downto fun gcd_poly ---
   465 "-------- example 187b";
   466 val t = str2term "(8 * x^^^2 * y * z ) / (18 * x * y^^^2 * z )";
   467 val SOME (t', asm) = rewrite_set_ thy false cancel_p t;
   468 if (term2str t', terms2str asm) = ("4 * x / (9 * y)", "[\"2 * (z * (y * x)) ~= 0\"]")
   469 then () else error "rational.sml cancel Schalk 187b";
   470 *)
   471 
   472 (* doesn't terminate !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
   473   see --- fun rewrite_set_ downto fun gcd_poly ---
   474 "-------- example 187c";
   475 val t = str2term "(9 * x^^^5 * y^^^2 * z^^^4) / (15 * x^^^6 * y^^^3 * z )";
   476 val SOME (t', asm) = rewrite_set_ thy false cancel_p t;
   477 if (term2str t', terms2str asm) = 
   478   ("3 * z ^^^ 3 / (5 * (y * x))", "[\"3 * (z * (y ^^^ 2 * x ^^^ 5)) ~= 0\"]") 
   479 then () else error "rational.sml cancel Schalk 187c";
   480 *)
   481 
   482 "-------- example 188a";
   483 val t = str2term "(-8 + 8 * x) / (-9 + 9 * x)";
   484   is_expanded (str2term "8 * x + -8");
   485 val SOME (t', asm) = rewrite_set_ thy false cancel_p t;
   486 if (term2str t', terms2str asm) = ("8 / 9", "[]")
   487 then () else error "rational.sml cancel Schalk 188a";
   488 
   489 val t = str2term "(8*((-1) + x))/(9*((-1) + x))";
   490 val SOME (t, _) = rewrite_set_ thy false make_polynomial t;
   491 if (term2str t', terms2str asm) = ("8 / 9", "[]")
   492 then () else error "rational.sml cancel Schalk make_polynomial 1";
   493 
   494 "-------- example 188b";
   495 val t = str2term "(-15 + 5 * x) / (-18 + 6 * x)";
   496 val SOME (t', asm) = rewrite_set_ thy false cancel_p t;
   497 if (term2str t', terms2str asm) = ("5 / 6", "[]")
   498 then () else error "rational.sml cancel Schalk 188b";
   499 
   500 "-------- example 188c";
   501 val t = str2term "(a + -1 * b) / (b + -1 * a)";
   502 val SOME (t', asm) = rewrite_set_ thy false  cancel_p t;
   503 if (term2str t', terms2str asm) = ("-1 / 1", "[]")
   504 then () else error "rational.sml cancel Schalk 188c";
   505 
   506 is_expanded (str2term "a + -1 * b") = true;
   507 val t = str2term "((-1)*(b + (-1) * a))/(1*(b + (-1) * a))";
   508 val SOME (t', asm) = rewrite_set_ thy false make_polynomial t;
   509 if (term2str t', terms2str asm) = ("(a + -1 * b) / (-1 * a + b)", "[]")
   510 then () else error "rational.sml cancel Schalk make_polynomial 2";
   511 
   512 "-------- example 190a";
   513 val t = str2term "( 27 * a^^^3 + 9 * a^^^2 + 3 * a + 1 ) / ( 27 * a^^^3 + 18 * a^^^2 + 3 * a )";
   514 val SOME (t', asm) = rewrite_set_ thy false cancel_p t;
   515 if (term2str t', terms2str asm) = 
   516   ("(1 + 9 * a ^^^ 2) / (3 * a + 9 * a ^^^ 2)", "[\"3 * a + 9 * a ^^^ 2 ~= 0\"]")
   517 then () else error "rational.sml cancel Schalk 190a";
   518 
   519 "-------- example 190c";
   520 val t = str2term "((1 + 9 * a ^^^ 2)*(1 + 3 * a))/((3 * a + 9 * a ^^^ 2)*(1 + 3 * a))";
   521 val SOME (t', asm) = rewrite_set_ thy false make_polynomial t;
   522 if (term2str t', terms2str asm) = 
   523   ("(1 + 3 * a + 9 * a ^^^ 2 + 27 * a ^^^ 3) /\n(3 * a + 18 * a ^^^ 2 + 27 * a ^^^ 3)", "[]")
   524 then () else error "rational.sml make_polynomial Schalk 190c";
   525 
   526 "-------- example 191a";
   527 val t = str2term "( x^^^2 + -1 * y^^^2 ) / ( x + y )";
   528   is_expanded (str2term "x^^^2 + -1 * y^^^2") = false; (*!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!*)
   529   is_expanded (str2term "x + y") = true;
   530 val SOME (t', asm) = rewrite_set_ thy false cancel_p t;
   531 if (term2str t', terms2str asm) = ("(x + -1 * y) / 1", "[]")
   532 then () else error "rational.sml make_polynomial Schalk 191a";
   533 
   534 "-------- example 191b";
   535 val t = str2term "((x + (-1) * y)*(x + y))/((1)*(x + y))";
   536 val SOME (t', asm) = rewrite_set_ thy false make_polynomial t;
   537 if (term2str t', terms2str asm) = ("(x ^^^ 2 + -1 * y ^^^ 2) / (x + y)", "[]")
   538 then () else error "rational.sml make_polynomial Schalk 191b";
   539 
   540 "-------- example 191c";
   541 val t = str2term "( 9 * x^^^2 + -30 * x + 25 ) / ( 9 * x^^^2 + -25 )";
   542   is_expanded (str2term "9 * x^^^2 + -30 * x + 25") = true;
   543   is_expanded (str2term "25 + -30*x + 9*x^^^2") = true;
   544   is_expanded (str2term "-25 + 9*x^^^2") = true;
   545 
   546 val t = str2term "(((-5) + 3 * x)*((-5) + 3 * x))/((5 + 3 * x)*((-5) + 3 * x))";
   547 val SOME (t', asm) = rewrite_set_ thy false make_polynomial t;
   548 if (term2str t', terms2str asm) = ("(25 + -30 * x + 9 * x ^^^ 2) / (-25 + 9 * x ^^^ 2)", "[]")
   549 then () else error "rational.sml make_polynomial Schalk 191c";
   550 
   551 "-------- example 192b";
   552 val t = str2term "( 7 * x^^^3 + -1 * x^^^2 * y ) / ( 7 * x * y^^^2 + -1 *  y^^^3 )";
   553 val SOME (t', asm) = rewrite_set_ thy false cancel_p t;
   554 if (term2str t', terms2str asm) = ("x ^^^ 2 / y ^^^ 2", "[\"y ^^^ 2 ~= 0\"]")
   555 then () else error "rational.sml cancel_p Schalk 192b";
   556 
   557 val t = str2term "((x ^^^ 2)*(7 * x + (-1) * y))/((y ^^^ 2)*(7 * x + (-1) * y))";
   558 val SOME (t', asm) = rewrite_set_ thy false make_polynomial t;
   559 if (term2str t', terms2str asm) = 
   560   ("(7 * x ^^^ 3 + -1 * x ^^^ 2 * y) / (7 * x * y ^^^ 2 + -1 * y ^^^ 3)", "[]")
   561 then () else error "rational.sml make_polynomial Schalk 192b";
   562 
   563 val t = str2term "((x ^^^ 2)*(7 * x + (-1) * y))/((y ^^^ 2)*(7 * x + (-1) * y))";
   564 val SOME (t', asm) = rewrite_set_ thy false make_polynomial t;
   565 if (term2str t', terms2str asm) = 
   566   ("(7 * x ^^^ 3 + -1 * x ^^^ 2 * y) / (7 * x * y ^^^ 2 + -1 * y ^^^ 3)", "[]")
   567 then () else error "rational.sml make_polynomial Schalk WN050929 not working";
   568 
   569 "-------- example 193a";
   570 val t = str2term "( x^^^2 + -6 * x + 9 ) / ( x^^^2 + -9 )";
   571 val SOME (t', asm) = rewrite_set_ thy false cancel_p t;
   572 if (term2str t', terms2str asm) = ("(-3 + x) / (3 + x)", "[\"3 + x ~= 0\"]")
   573 then () else error "rational.sml cancel_p Schalk 193a";
   574 
   575 "-------- example 193b";
   576 val t = str2term "( x^^^2 + -8 * x + 16 ) / ( 2 * x^^^2 + -32 )";
   577 val SOME (t', asm) = rewrite_set_ thy false cancel_p t;
   578 if (term2str t', terms2str asm) = ("(-4 + x) / (8 + 2 * x)", "[\"8 + 2 * x ~= 0\"]")
   579 then () else error "rational.sml cancel_p Schalk 193b";
   580 
   581 "-------- example 193c";
   582 val t = str2term "( 2 * x + -50 * x^^^3 ) / ( 25 * x^^^2 + -10 * x + 1 )";
   583 val SOME (t', asm) = rewrite_set_ thy false cancel_p t;
   584 if (term2str t', terms2str asm) = 
   585   ("(2 * x + 10 * x ^^^ 2) / (1 + -5 * x)", "[\"1 + -5 * x ~= 0\"]")
   586 then () else error "rational.sml cancel_p Schalk 193c";
   587 
   588 (*WN:*)
   589 val t = str2term "(-25 + 9*x^^^2)/(5 + 3*x)";
   590 val SOME (t, asm) = rewrite_set_ thy false cancel_p t;
   591 if (term2str t', terms2str asm) = ("(2 * x + 10 * x ^^^ 2) / (1 + -5 * x)", "[]")
   592 then () else error "rational.sml cancel WN 1";
   593 
   594 "-------- example heuberger";
   595 val t = str2term ("(x^^^4 + x * y + x^^^3 * y + y^^^2) / " ^
   596   "(x + 5 * x^^^2 + y + 5 * x * y + x^^^2 * y^^^3 + x * y^^^4)");
   597 val SOME (t', asm) = rewrite_set_ thy false cancel_p t;
   598 if (term2str t', terms2str asm) = 
   599   ("(x ^^^ 3 + y) / (1 + 5 * x + x * y ^^^ 3)", "[\"1 + 5 * x + x * y ^^^ 3 ~= 0\"]")
   600 then () else error "rational.sml cancel_p heuberger";
   601 
   602 "-------- rewrite_set_ add_fractions_p from: Mathematik 1 Schalk -------------";
   603 "-------- rewrite_set_ add_fractions_p from: Mathematik 1 Schalk -------------";
   604 "-------- rewrite_set_ add_fractions_p from: Mathematik 1 Schalk -------------";
   605 (*deleted example 204 ... 236b at update Isabelle2012-->2013*)
   606 
   607 "-------- integration lev.1 -- lev.5: cancel_p_ & add_fractions_p_ -----------";
   608 "-------- integration lev.1 -- lev.5: cancel_p_ & add_fractions_p_ -----------";
   609 "-------- integration lev.1 -- lev.5: cancel_p_ & add_fractions_p_ -----------";
   610 val t = str2term ("123 = (a*x)/(b*x) + (c*x)/(d*x) + (e*x)/(f*x::real)");
   611 "-------- gcd_poly integration level 1: works on exact term";
   612 if NONE = cancel_p_ thy t then () else error "cancel_p_ works on exact fraction";
   613 if NONE = add_fraction_p_ thy t then () else error "add_fraction_p_ works on exact fraction";
   614 
   615 "-------- gcd_poly integration level 2: picks out ONE appropriate subterm";
   616 val SOME (t', asm) = rewrite_set_ thy false cancel_p t;
   617 if term2str t' = "123 = a * x / (b * x) + c * x / (d * x) + e / f" 
   618 then () else error "level 2, rewrite_set_ cancel_p: changed";
   619 val SOME (t', asm) = rewrite_set_ thy false add_fractions_p t;
   620 if term2str t' = "123 = (b * c * x + a * d * x) / (b * d * x) + e * x / (f * x)"
   621 then () else error "level 2, rewrite_set_ add_fractions_p: changed";
   622 
   623 "-------- gcd_poly integration level 3: rewrites all appropriate subterms";
   624 val SOME (t', asm) = rewrite_set_ thy false cancel_p_rls t;
   625 if term2str t' = "123 = a / b + c / d + e / f"
   626 then () else error "level 3, rewrite_set_ cancel_p_rls: changed";
   627 val SOME (t', asm) = rewrite_set_ thy false add_fractions_p_rls t; (*CREATE add_fractions_p_rls*)
   628 if term2str t' = "123 = (b * d * e * x + b * c * f * x + a * d * f * x) / (b * d * f * x)"
   629 then () else error "level 3, rewrite_set_ add_fractions_p_rls: changed";
   630 
   631 "-------- gcd_poly integration level 4: iteration cancel_p -- add_fraction_p";
   632 (* simpler variant *)
   633 val testrls = append_rls "testrls" e_rls [Rls_ cancel_p, Rls_ add_fractions_p]
   634 val SOME (t', asm) = rewrite_set_ thy false testrls t;
   635 (*trace_rewrite := false;
   636 #  rls: testrls on: 123 = a * x / (b * x) + c * x / (d * x) + e * x / (f * x) 
   637 ##  rls: cancel_p on: 123 = a * x / (b * x) + c * x / (d * x) + e * x / (f * x) 
   638 ##  rls: add_fractions_p on: 123 = a * x / (b * x) + c * x / (d * x) + e / f 
   639 ##  rls: cancel_p on: 123 = (b * c * x + a * d * x) / (b * d * x) + e / f 
   640 ##  rls: add_fractions_p on: 123 = (b * c + a * d) / (b * d) + e / f 
   641 ##  rls: cancel_p on: 123 = (b * d * e + b * c * f + a * d * f) / (b * d * f) 
   642 ##  rls: add_fractions_p on: 123 = (b * d * e + b * c * f + a * d * f) / (b * d * f) *)
   643 if term2str t' = "123 = (b * d * e + b * c * f + a * d * f) / (b * d * f)"
   644 then () else error "level 4, rewrite_set_ *_p: changed";
   645 
   646 (* complicated variant *)
   647 val testrls_rls = append_rls "testrls_rls" e_rls [Rls_ cancel_p_rls, Rls_ add_fractions_p_rls];
   648 val SOME (t', asm) = rewrite_set_ thy false testrls_rls t;
   649 (*#  rls: testrls_rls on: 123 = a * x / (b * x) + c * x / (d * x) + e * x / (f * x) 
   650 ##  rls: cancel_p_rls on: 123 = a * x / (b * x) + c * x / (d * x) + e * x / (f * x) 
   651 ###  rls: cancel_p on: 123 = a * x / (b * x) + c * x / (d * x) + e * x / (f * x) 
   652 ###  rls: cancel_p on: 123 = a * x / (b * x) + c * x / (d * x) + e / f 
   653 ###  rls: cancel_p on: 123 = a * x / (b * x) + c / d + e / f 
   654 ###  rls: cancel_p on: 123 = a / b + c / d + e / f 
   655 ##  rls: add_fractions_p_rls on: 123 = a / b + c / d + e / f 
   656 ###  rls: add_fractions_p on: 123 = a / b + c / d + e / f 
   657 ###  rls: add_fractions_p on: 123 = (b * c + a * d) / (b * d) + e / f 
   658 ###  rls: add_fractions_p on: 123 = (b * d * e + b * c * f + a * d * f) / (b * d * f) 
   659 ##  rls: cancel_p_rls on: 123 = (b * d * e + b * c * f + a * d * f) / (b * d * f) 
   660 ###  rls: cancel_p on: 123 = (b * d * e + b * c * f + a * d * f) / (b * d * f) 
   661 ##  rls: add_fractions_p_rls on: 123 = (b * d * e + b * c * f + a * d * f) / (b * d * f) 
   662 ###  rls: add_fractions_p on: 123 = (b * d * e + b * c * f + a * d * f) / (b * d * f) *)
   663 if term2str t' = "123 = (b * d * e + b * c * f + a * d * f) / (b * d * f)"
   664 then () else error "level 4, rewrite_set_ *_p_rls: changed"
   665 
   666 "-------- gcd_poly integration level 5: cancel_p & add_fraction_p within norm_Rational";
   667 val SOME (t', asm) = rewrite_set_ thy false norm_Rational t;
   668 if term2str t' = "123 = (a * d * f + b * c * f + b * d * e) / (b * d * f)"
   669 then () else error "level 5, rewrite_set_ norm_Rational: changed"
   670 
   671 "-------- reverse rewrite ----------------------------------------------------";
   672 "-------- reverse rewrite ----------------------------------------------------";
   673 "-------- reverse rewrite ----------------------------------------------------";
   674 (** the term for which reverse rewriting is demonstrated **)
   675 val t = str2term "(9 + -1 * x ^^^ 2) / (9 + 6 * x + x ^^^ 2)";
   676 val Rrls {scr = Rfuns {init_state = ini, locate_rule = loc,
   677   next_rule = nex, normal_form = nor, ...},...} = cancel_p;
   678 
   679 (** normal_form produces the result in ONE step **)
   680   val SOME (t',_) = nor t;
   681 if term2str t' = "(3 + -1 * x) / (3 + x)" then ()
   682 else error "rational.sml normal_form (9 - x ^^^ 2) / (9 - 6 * x + x ^^^ 2)";
   683 
   684 (** initialize the interpreter state used by the 'me' **)
   685   val (t, _, revsets, _) = ini t;
   686 
   687 if length (hd revsets) = 11 then () else error "length of revset changed";
   688 if (revsets |> nth 1 |> nth 1 |> id_of_thm) = 
   689   (@{thm realpow_twoI} |> string_of_thm |> thmID_of_derivation_name)
   690 then () else error "first element of revset changed";
   691 if
   692 (revsets |> nth 1 |> nth 1 |> rule2str) = "Thm (\"realpow_twoI\",??.unknown)" andalso
   693 (revsets |> nth 1 |> nth 2 |> rule2str) = 
   694   "Thm (\"sym_#power_Float ((3,0), (0,0)) __ ((2,0), (0,0))\",??.unknown)" andalso
   695 (revsets |> nth 1 |> nth 3 |> rule2str) = 
   696   "Thm (\"sym_#mult_Float ((2,0), (0,0)) __ ((3,0), (0,0))\",??.unknown)" andalso
   697 (revsets |> nth 1 |> nth 4 |> rule2str) = 
   698   "Thm (\"sym_#mult_Float ((~1,0), (0,0)) __ ((3,0), (0,0))\",??.unknown)" andalso
   699 (revsets |> nth 1 |> nth 5 |> rule2str) = 
   700   "Thm (\"sym_#mult_Float ((3,0), (0,0)) __ ((3,0), (0,0))\",??.unknown)" andalso
   701 (revsets |> nth 1 |> nth 6 |> rule2str) = "Rls_ (\"sym_order_mult_rls_\")" andalso
   702 (revsets |> nth 1 |> nth 7 |> rule2str) = 
   703   "Thm (\"sym_mult_assoc\",Groups.semigroup_mult_class.mult_assoc)"
   704 then () else error "first 7 elements in revset changed"
   705 
   706 (** find the rule 'r' to apply to term 't' **)
   707 (*/------- WN1309: since cancel_ (accepted "-" between monomials) has been replaced by cancel_p_ 
   708   for Isabelle2013, we don't get a working revset, but non-termination:
   709 
   710   val SOME (r as (Thm (str, thm))) = nex revsets t;
   711   :
   712 ((3 * 3 + -1 * x * x) / (3 * 3 + 2 * 3 * x + x * x), 
   713   Rls_ ("sym_order_mult_rls_"), ((3 * 3 + -1 * (x * x)) / (3 * 3 + 2 * (3 * x) + x * x), []))","
   714 ((3 * 3 + -1 * (x * x)) / (3 * 3 + 2 * (3 * x) + x * x), 
   715   Thm ("sym_mult_assoc",""), ((3 * 3 + -1 * (x * x)) / (3 * 3 + 2 * 3 * x + x * x), []))","
   716 ((3 * 3 + -1 * (x * x)) / (3 * 3 + 2 * 3 * x + x * x), 
   717   Thm ("sym_mult_assoc",""), ((3 * 3 + -1 * x * x) / (3 * 3 + 2 * 3 * x + x * x), []))","
   718 ((3 * 3 + -1 * x * x) / (3 * 3 + 2 * 3 * x + x * x), Rls_ ("sym_order_mult_rls_"), ((3 * 3 + -1 * (x * x)) / (3 * 3 + 2 * (3 * x) + x * x), []))","
   719  :
   720 ### Isabelle2002:
   721   Thm ("sym_#mult_2_3", "6 = 2 * 3")
   722 ### Isabelle2009-2 for cancel_ (not cancel_p_):
   723 if str = "sym_#power_Float ((3,0), (0,0)) __ ((2,0), (0,0))"
   724    andalso string_of_thm thm = 
   725            (string_of_thm o make_thm o (cterm_of (@{theory "Isac"})))
   726                (Trueprop $ (term_of o the o (parse thy)) "9 = 3 ^^^ 2") then ()
   727 else error "rational.sml next_rule (9 - x ^^^ 2) / (9 - 6 * x + x ^^^ 2)";
   728 \---------------------------------------------------------------------------------------/*)
   729 
   730 (** check, if the rule 'r' applied by the user to 't' belongs to the ruleset;
   731   if the rule is OK, the term resulting from applying the rule is returned,too;
   732   there might be several rule applications inbetween,
   733   which are listed after the head in reverse order **)
   734 (*/-------------------------------------------- Isabelle2013: this gives "error id_of_thm";
   735   we don't repair this, because interaction within "reverse rewriting" never worked properly:
   736 
   737   val (r, (t, asm))::_ = loc revsets t r;
   738 if term2str t = "(9 - x ^^^ 2) / (3 ^^^ 2 + 6 * x + x ^^^ 2)" andalso asm = []
   739 then () else error "rational.sml locate_rule (9 - x ^^^ 2) / (9 - 6 * x + x ^^^ 2)";
   740 
   741 (* find the next rule to apply *)
   742   val SOME (r as (Thm (str, thm))) = nex revsets t;
   743 if str = "sym_#power_Float ((3,0), (0,0)) __ ((2,0), (0,0))" andalso
   744    string_of_thm thm = (string_of_thm o make_thm o (cterm_of (@{theory "Isac"})))
   745                 (Trueprop $ (term_of o the o (parse thy)) "9 = 3 ^^^ 2") then ()
   746 else error "rational.sml next_rule (9 - x ^^^ 2) / (9 - 6 * x + x ^^^ 2)";
   747 
   748 (*check the next rule*)
   749   val (r, (t, asm)) :: _ = loc revsets t r;
   750 if term2str t = "(3 ^^^ 2 - x ^^^ 2) / (3 ^^^ 2 + 6 * x + x ^^^ 2)" then ()
   751 else error "rational.sml locate_rule (9 - x ^^^ 2) / (9 - 6 * x + x ^^^ 2) II";
   752 
   753 (*find and check the next rules, rewrite*)
   754   val SOME r = nex revsets t;
   755   val (r,(t,asm))::_ = loc revsets t r;
   756 if term2str t = "(3 ^^^ 2 - x ^^^ 2) / (3 ^^^ 2 + 2 * 3 * x + x ^^^ 2)" then ()
   757 else error "rational.sml locate_rule II";
   758 
   759   val SOME r = nex revsets t;
   760   val (r,(t,asm))::_ = loc revsets t r;
   761 if term2str t = "(3 - x) * (3 + x) / (3 ^^^ 2 + 2 * 3 * x + x ^^^ 2)" then ()
   762 else error "rational.sml next_rule II";
   763 
   764   val SOME r = nex revsets t;
   765   val (r,(t,asm))::_ = loc revsets t r;
   766 if term2str t = "(3 - x) * (3 + x) / ((3 + x) * (3 + x))" then ()
   767 else error "rational.sml next_rule III";
   768 
   769   val SOME r = nex revsets t;
   770   val (r, (t, asm)) :: _ = loc revsets t r;
   771   val ss = term2str t;
   772 if ss = "(3 - x) / (3 + x)" andalso terms2str asm = "[\"3 + x ~= 0\"]" then ()
   773 else error "rational.sml: new behav. in rev-set cancel";
   774 \--------------------------------------------------------------------------------------/*)
   775 
   776 "-------- 'reverse-ruleset' cancel_p -----------------------------------------";
   777 "-------- 'reverse-ruleset' cancel_p -----------------------------------------";
   778 "-------- 'reverse-ruleset' cancel_p -----------------------------------------";
   779 (*WN130909: the example below shows, why "reverse rewriting" only worked for
   780   special cases.*)
   781 
   782 (*the term for which reverse rewriting is demonstrated*)
   783 val t = str2term "(9 + (-1)*x^^^2) / (9 + ((-6)*x + x^^^2))";
   784 val Rrls {scr=Rfuns {init_state=ini,locate_rule=loc,
   785 		       next_rule=nex,normal_form=nor,...},...} = cancel_p;
   786 
   787 (*normal_form produces the result in ONE step*)
   788 val SOME (t',_) = nor t; 
   789 term2str t' = "(3 + 1 * x) / (3 + -1 * x)";
   790 
   791 (*initialize the interpreter state used by the 'me'*)
   792 val SOME (t', asm) = cancel_p_ thy t;
   793 term2str t' = "(3 + x) / (3 + -1 * x)" (*true*);
   794 terms2str asm = "[\"3 + -1 * x ~= 0\"]" (*true*);
   795 val (t,_,revsets,_) = ini t;
   796 
   797 (* WN.10.10.02: dieser Fall terminiert nicht 
   798            (make_polynomial enth"alt zu viele rules)
   799 WN060823 'init_state' requires rewriting on specified location in the term
   800 print_depth 99; Rfuns; print_depth 3;
   801 WN060831 cycling "sym_order_mult_rls_" "sym_mult_assoc"
   802          as was with make_polynomial before ?!?*)
   803 
   804 val SOME r = nex revsets t;
   805 eq_Thm (r, Thm ("sym_#power_Float ((3,0), (0,0)) __ ((2,0), (0,0))", 
   806 		mk_thm thy "9 = 3 ^^^ 2"));
   807 (*WN060831 *** id_of_thm
   808            Exception- ERROR raised ...
   809 val (r,(t,asm))::_ = loc revsets t r;
   810 term2str t;
   811 
   812   val SOME r = nex revsets t;
   813   val (r,(t,asm))::_ = loc revsets t r;
   814   term2str t;
   815 *)                    
   816 
   817 "-------- examples: rls norm_Rational ----------------------------------------";
   818 "-------- examples: rls norm_Rational ----------------------------------------";
   819 "-------- examples: rls norm_Rational ----------------------------------------";
   820 val t = str2term "(3*x+5)/18 - x/2  - -(3*x - 2)/9 = 0";
   821 val SOME (t',_) = rewrite_set_ thy false norm_Rational t; term2str t';
   822 if term2str t' = "1 / 18 = 0" then () else error "rational.sml 1";
   823 
   824 val t = str2term "(17*x - 51)/9 - (-(13*x - 3)/6) + 11 - (9*x - 7)/4 = 0";
   825 val SOME (t',_) = rewrite_set_ thy false norm_Rational t; term2str t';
   826 if term2str t' = "(237 + 65 * x) / 36 = 0" then () 
   827 else error "rational.sml 2";
   828 
   829 val t = str2term "(1/2 + (5*x)/2)^^^2 - ((13*x)/2 - 5/2)^^^2 - (6*x)^^^2 + 29";
   830 val SOME (t',_) = rewrite_set_ thy false norm_Rational t; term2str t';
   831 if term2str t' = "23 + 35 * x + -72 * x ^^^ 2" then ()
   832 else error "rational.sml 3";
   833 
   834 (*trace_rewrite:=true;*)
   835 val t = str2term "Not (6*x is_atom)";
   836 val SOME (t',_) = rewrite_set_ thy false powers_erls t; term2str t';
   837 "HOL.True";
   838 val t = str2term "1 < 2";
   839 val SOME (t',_) = rewrite_set_ thy false powers_erls t; term2str t';
   840 "HOL.True";
   841 
   842 val t = str2term "(6*x)^^^2";
   843 val SOME (t',_) = rewrite_ thy dummy_ord powers_erls false 
   844 			   (num_str @{thm realpow_def_atom}) t;
   845 if term2str t' = "6 * x * (6 * x) ^^^ (2 + -1)" then ()
   846 else error "rational.sml powers_erls (6*x)^^^2";
   847 
   848 val t = str2term "-1 * (-2 * (5 / 2 * (13 * x / 2)))";
   849 val SOME (t',_) = rewrite_set_ thy false norm_Rational t; term2str t';
   850 if term2str t' = "65 * x / 2" then () else error "rational.sml 4";
   851 
   852 val t = str2term "1 - ((13*x)/2 - 5/2)^^^2";
   853 val SOME (t',_) = rewrite_set_ thy false norm_Rational t; term2str t';
   854 if term2str t' = "(-21 + 130 * x + -169 * x ^^^ 2) / 4" then () 
   855 else error "rational.sml 5";
   856 
   857 (*SRAM Schalk I, p.92 Nr. 609a*)
   858 val t = str2term "2*(3 - x/5)/3 - 4*(1 - x/3) - x/3 - 2*(x/2 - 1/4)/27 +5/54";
   859 val SOME (t',_) = rewrite_set_ thy false norm_Rational t; term2str t';
   860 if term2str t' = "(-255 + 112 * x) / 135" then () 
   861 else error "rational.sml 6";
   862 
   863 (*SRAM Schalk I, p.92 Nr. 610c*)
   864 val t = str2term "((x- 1)/(x+1) + 1) / ((x- 1)/(x+1) - (x+1)/(x- 1)) - 2";
   865 val SOME (t',_) = rewrite_set_ thy false norm_Rational t; term2str t';
   866 if term2str t' = "(-3 + -1 * x) / 2" then () else error "rational.sml 7";
   867 
   868 (*SRAM Schalk I, p.92 Nr. 476a*)
   869 val t = str2term "(x^^^2/(1 - x^^^2) + 1)/(x/(1 - x) + 1) * (1 + x)";
   870 (*. a/b : c/d translated to a/b * d/c .*)
   871 val SOME (t',_) = rewrite_set_ thy false norm_Rational t; term2str t';
   872 if term2str t' = "1" then () else error "rational.sml 8";
   873 
   874 (*Schalk I, p.92 Nr. 472a*)
   875 val t = str2term "((8*x^^^2 - 32*y^^^2)/(2*x + 4*y))/((4*x - 8*y)/(x + y))";
   876 val SOME (t',_) = rewrite_set_ thy false norm_Rational t; term2str t';
   877 if term2str t' = "x + y" then () else error "rational.sml p.92 Nr. 472a";
   878 
   879 (*Schalk I, p.70 Nr. 480b: SEE rational.sml --- nonterminating rls norm_Rational ---*)
   880 
   881 (*WN130910 add_fractions_p exception Div raised + history:
   882 ### WN.2.6.03 from rlang.sml 56a 
   883 val t = str2term "(a + b * x) / (a + -1 * (b * x)) + (-1 * a + b * x) / (a + b * x) = 4 * (a * b) / (a ^^^ 2 + -1 * b ^^^ 2)";
   884 val NONE = rewrite_set_ thy false add_fractions_p t;
   885 
   886 THE ERROR ALREADY OCCURS IN THIS PART:
   887 val t = str2term "(a + b * x) / (a + -1 * (b * x)) + (-1 * a + b * x) / (a + b * x)";
   888 val NONE = add_fraction_p_ thy t;
   889 
   890 SEE Test_Some.thy: section {* add_fractions_p downto exception Div raised ===
   891 *)
   892 
   893 "-------- rational numerals --------------------------------------------------";
   894 "-------- rational numerals --------------------------------------------------";
   895 "-------- rational numerals --------------------------------------------------";
   896 (*SRA Schalk I, p.40 Nr. 164b *)
   897 val t = str2term "(47/6 - 76/9 + 13/4)/(35/12)";
   898 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
   899 term2str t;
   900 if term2str t = "19 / 21" then ()
   901 else error "rational.sml: diff.behav. in norm_Rational_mg 1";
   902 
   903 (*SRA Schalk I, p.40 Nr. 166a *)
   904 val t = str2term "((5/4)/(4+22/7) + 37/20)*(110/3 - 110/9 * 23/11)";
   905 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
   906 term2str t;
   907 if term2str t = "45 / 2" then ()
   908 else error "rational.sml: diff.behav. in norm_Rational_mg 2";
   909 
   910 "-------- examples cancellation from: Mathematik 1 Schalk --------------------";
   911 "-------- examples cancellation from: Mathematik 1 Schalk --------------------";
   912 "-------- examples cancellation from: Mathematik 1 Schalk --------------------";
   913 (* e190c Stefan K.*)
   914 val t = str2term "((1 + 9*a^^^2) * (1 + 3*a)) / ((3*a + 9*a^^^2) * (1 + 3*a))";
   915 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
   916 if term2str t = "(1 + 9 * a ^^^ 2) / (3 * a + 9 * a ^^^ 2)"
   917 then () else error "rational.sml: diff.behav. in norm_Rational_mg 3";
   918 
   919 (* e192b Stefan K.*)
   920 val t = str2term "(x^^^2 * (7*x + (-1)*y))  /  (y^^^2 * (7*x + (-1)*y))";
   921 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
   922 if term2str t = "x ^^^ 2 / y ^^^ 2"
   923 then () else error "rational.sml: diff.behav. in norm_Rational_mg 4";
   924 
   925 (*SRC Schalk I, p.66 Nr. 379c *)
   926 val t = str2term "(a - b)/(b - a)";
   927 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
   928 term2str t;
   929 if term2str t = "-1"
   930 then () else error "rational.sml: diff.behav. in norm_Rational_mg 5";
   931 
   932 (*SRC Schalk I, p.66 Nr. 380b *)
   933 val t = str2term "15*(3*x + 3) * (4*x + 9)  /  (12*(2*x + 7) * (5*x + 5))";
   934 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
   935 if term2str t = "(27 + 12 * x) / (28 + 8 * x)"
   936 then () else error "rational.sml: diff.behav. in norm_Rational_mg 6";
   937 
   938 (*Schalk I, p.60 Nr. 215c: was not cancelled with Isabelle2002 *)
   939 val t = str2term "(a + b)^^^4 * (x - y)  /  ((x - y)^^^3 * (a + b)^^^2)";
   940 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
   941 if term2str t = "(a ^^^ 2 + 2 * a * b + b ^^^ 2) / (x ^^^ 2 + -2 * x * y + y ^^^ 2)"
   942 then () else error "rational.sml: diff.behav. in norm_Rational_mg 7";
   943 
   944 (*SRC Schalk I, p.66 Nr. 381b *)
   945 val t = str2term 
   946 "(4*x^^^2 - 20*x + 25)/(2*x - 5)^^^3";
   947 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
   948 if term2str t = "1 / (-5 + 2 * x)"
   949 then () else error "rational.sml: diff.behav. in norm_Rational_mg 9";
   950 
   951 (* e190c Stefan K.*)
   952 val t = str2term "((1 + 9*a^^^2) * (1 + 3*a))  /  ((3*a + 9*a^^^2) * (1 + 3 * a))";
   953 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
   954 if term2str t =  "(1 + 9 * a ^^^ 2) / (3 * a + 9 * a ^^^ 2)"
   955 then () else error "rational.sml: diff.behav. in norm_Rational_mg 3";
   956 
   957 (* e192b Stefan K.*)
   958 val t = str2term "(x^^^2 * (7*x + (-1)*y))  /  (y^^^2 * (7*x + (-1)*y))";
   959 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
   960 if term2str t = "x ^^^ 2 / y ^^^ 2"
   961 then () else error "rational.sml: diff.behav. in norm_Rational_mg 4";
   962 
   963 (*SRC Schalk I, p.66 Nr. 379c *)
   964 val t = str2term "(a - b) / (b - a)";
   965 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
   966 if term2str t = "-1"
   967 then () else error "rational.sml: diff.behav. in norm_Rational_mg 5";
   968 
   969 (*SRC Schalk I, p.66 Nr. 380b *)
   970 val t = str2term "15*(3*x + 3) * (4*x + 9)  /  (12*(2*x + 7) * (5*x + 5))";
   971 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
   972 if term2str t = "(27 + 12 * x) / (28 + 8 * x)"
   973 then () else error "rational.sml: diff.behav. in norm_Rational_mg 6";
   974 
   975 (*Schalk I, p.60 Nr. 215c *)
   976 val t = str2term "(a + b)^^^4 * (x - y)  /  ((x - y)^^^3 * (a + b)^^^2)";
   977 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
   978 if term2str t = "(a ^^^ 2 + 2 * a * b + b ^^^ 2) / (x ^^^ 2 + -2 * x * y + y ^^^ 2)"
   979 then () else error "Schalk I, p.60 Nr. 215c: with Isabelle2002 cancellation incomplete, changed";
   980 
   981 (* extreme example from somewhere *)
   982 val t = str2term 
   983     ("(a^^^4 * x  +  -1*a^^^4 * y  +  4*a^^^3 * b * x  +  -4*a^^^3 * b * y  + " ^
   984       "6*a^^^2 * b^^^2 * x  +  -6*a^^^2 * b^^^2 * y  +  4*a * b^^^3 * x  +  -4*a * b^^^3 * y  + " ^
   985       "b^^^4 * x  +  -1*b^^^4 * y) " ^
   986   " / (a^^^2 * x^^^3  +  -3*a^^^2 * x^^^2 * y  +  3*a^^^2 * x * y^^^2  +  -1*a^^^2 * y^^^3 + " ^
   987       "2*a * b * x^^^3  +  -6*a * b * x^^^2 * y  +  6*a * b * x * y^^^2  +  -2*a * b * y^^^3 + " ^
   988       "b^^^2 * x^^^3  +  -3*b^^^2 * x^^^2 * y  +  3*b^^^2 * x * y^^^2  +  -1*b ^^^ 2 * y ^^^ 3)")
   989 val SOME (t, _) = rewrite_set_ thy false cancel_p t;
   990 if term2str t = "(a ^^^ 2 + 2 * a * b + b ^^^ 2) / (x ^^^ 2 + -2 * x * y + y ^^^ 2)"
   991 then () else error "with Isabelle2002: NONE -- now SOME changed";
   992 
   993 (*Schalk I, p.66 Nr. 381a *)
   994 (* ATTENTION: here the rls is very slow. In Isabelle2002 this required 2 min *)
   995 val t = str2term "18*(a + b)^^^3 * (a - b)^^^2 / (72*(a - b)^^^3 * (a + b)^^^2)";
   996 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
   997 if term2str t = "(a + b) / (4 * a + -4 * b)"
   998 then () else error "rational.sml: diff.behav. in norm_Rational_mg 8";
   999 
  1000 (*SRC Schalk I, p.66 Nr. 381b *)
  1001 val t = str2term "(4*x^^^2 - 20*x + 25) / (2*x - 5)^^^3";
  1002 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1003 if term2str t = "1 / (-5 + 2 * x)"
  1004 then () else error "rational.sml: diff.behav. in norm_Rational_mg 9";
  1005 
  1006 (*SRC Schalk I, p.66 Nr. 381c *)
  1007 val t = str2term "(27*a^^^3 + 9*a^^^2+3*a+1) / (27*a^^^3 + 18*a^^^2+3*a)";
  1008 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1009 if term2str t = "(1 + 9 * a ^^^ 2) / (3 * a + 9 * a ^^^ 2)"
  1010 then () else error "rational.sml: diff.behav. in norm_Rational_mg 10";
  1011 
  1012 (*SRC Schalk I, p.66 Nr. 383a *)
  1013 val t = str2term "(5*a^^^2 - 5*a*b) / (a - b)^^^2";
  1014 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1015 if term2str t = "-5 * a / (-1 * a + b)"
  1016 then () else error "rational.sml: diff.behav. in norm_Rational_mg 11";
  1017 
  1018 "----- NOT TERMINATING ?: worked before 0707xx";
  1019 val t = str2term "(a^^^2 - 1)*(b + 1) / ((b^^^2 - 1)*(a+1))";
  1020 (* WN130911 "exception Div raised" by 
  1021   cancel_p_ thy (str2term ("(-1 + -1 * b + a ^^^ 2 + a ^^^ 2 * b) /" ^
  1022                            "(-1 + -1 * a + b ^^^ 2 + a * b ^^^ 2)"))
  1023 
  1024 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1025 if term2str t = "(1 + -1 * a) / (1 + -1 * b)" then ()
  1026 else error "rational.sml MG tests 3e";
  1027 *)
  1028 
  1029 "-------- examples common denominator from: Mathematik 1 Schalk --------------";
  1030 "-------- examples common denominator from: Mathematik 1 Schalk --------------";
  1031 "-------- examples common denominator from: Mathematik 1 Schalk --------------";
  1032 (*SRA Schalk I, p.67 Nr. 403a *)
  1033 val t = str2term "4/x - 3/y - 1";
  1034 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1035 if term2str t = "(-3 * x + 4 * y + -1 * x * y) / (x * y)"
  1036 then () else error "rational.sml: diff.behav. in norm_Rational_mg 12";
  1037 
  1038 val t = str2term "(2*a+3*b)/(b*c) + (3*c+a)/(a*c) - (2*a^^^2+3*b*c)/(a*b*c)";
  1039 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1040 if term2str t = "4 / c"
  1041 then () else error "rational.sml: diff.behav. in norm_Rational_mg 13";
  1042 
  1043 (*SRA Schalk I, p.67 Nr. 410b *)
  1044 val t = str2term "1/(x+1) + 1/(x+2) - 2/(x+3)";
  1045 (* WN130911 non-termination due to non-termination of
  1046   cancel_p_ thy (str2term "(5 + 3 * x) / (6 + 11 * x + 6 * x ^^^ 2 + x ^^^ 3)")
  1047 
  1048 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1049 if term2str t = "(5 + 3 * x) / (6 + 11 * x + 6 * x ^^^ 2 + x ^^^ 3)"
  1050 then () else error "rational.sml: diff.behav. in norm_Rational_mg 14";
  1051 *)
  1052 
  1053 (*SRA Schalk I, p.67 Nr. 413b *)
  1054 val t = str2term "(1 + x)/(1 - x)  -  (1 - x)/(1 + x)  +  2*x/(1 - x^^^2)";
  1055 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1056 if term2str t = "6 * x / (1 + -1 * x ^^^ 2)"
  1057 then () else error "rational.sml: diff.behav. in norm_Rational_mg 15";
  1058 
  1059 (*SRA Schalk I, p.68 Nr. 414a *)
  1060 val t = str2term "(x + 2)/(x - 1)  +  (x - 3)/(x - 2)  -  (x + 1)/((x - 1)*(x - 2))";
  1061 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1062 if term2str t ="(-2 + -5 * x + 2 * x ^^^ 2) / (2 + -3 * x + x ^^^ 2)"
  1063 then () else error "rational.sml: diff.behav. in norm_Rational_mg 16";
  1064 
  1065 (*SRA Schalk I, p.68 Nr. 428b *)
  1066 val t = str2term 
  1067   "1/(a - b)^^^2  +  1/(a + b)^^^2  -  2/(a^^^2 - b^^^2)  -  4*(b^^^2 - 1)/(a^^^2 - b^^^2)^^^2";
  1068 (* WN130911 non-termination due to non-termination of
  1069   cancel_p_ thy (str2term "(4 + -4 * b ^^^ 2) / (a ^^^ 4 + -2 * (a ^^^ 2 * b ^^^ 2) + b ^^^ 4)")
  1070 
  1071 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1072 if term2str t = "4 / (a ^^^ 4 + -2 * a ^^^ 2 * b ^^^ 2 + b ^^^ 4)"
  1073 then () else error "rational.sml: diff.behav. in norm_Rational_mg 18";
  1074 *)
  1075 
  1076 (*SRA Schalk I, p.68 Nr. 430b *)
  1077 val t = str2term 
  1078   "a^^^2/(a - 3*b) - 108*a*b^^^3/((a+3*b)*(a^^^2 - 9*b^^^2)) - 9*b^^^2*(a - 3*b)/(a+3*b)^^^2";
  1079 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1080 if term2str t = "a + 3 * b"
  1081 then () else error "rational.sml: diff.behav. in norm_Rational_mg 19";
  1082 
  1083 (*SRA Schalk I, p.68 Nr. 432 *)
  1084 val t = str2term 
  1085   ("(a^^^2 + a*b) / (a^^^2 - b^^^2)  -  (b^^^2 - a*b) / (b^^^2 - a^^^2)  +  " ^
  1086   "a^^^2*(a - b) / (a^^^3 - a^^^2*b)  -  2*a*(a^^^2 - b^^^2) / (a^^^3 - a*b^^^2)  -  " ^
  1087   "2*b^^^2 / (a^^^2 - b^^^2)");
  1088 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1089 term2str t;
  1090 if term2str t = "0"
  1091 then () else error "rational.sml: diff.behav. in norm_Rational_mg 20";
  1092 
  1093 (* some example *)
  1094 val t = str2term "3*a / (a*b)  +  x/y";
  1095 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1096 if term2str t = "(3 * y + b * x) / (b * y)"
  1097 then () else error "rational.sml: diff.behav. in norm_Rational_mg 21";
  1098 
  1099 "-------- examples multiply and cancel from: Mathematik 1 Schalk -------------";
  1100 "-------- examples multiply and cancel from: Mathematik 1 Schalk -------------";
  1101 "-------- examples multiply and cancel from: Mathematik 1 Schalk -------------";
  1102 (*------- SRM Schalk I, p.68 Nr. 436a *)
  1103 val t = str2term "3*(x+y) / (15*(x - y))  *   25*(x - y)^^^2 / (18*(x + y)^^^2)";
  1104 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1105 if term2str t = "(-5 * x + 5 * y) / (-18 * x + -18 * y)"
  1106 then () else error "rational.sml: diff.behav. in norm_Rational_mg 22";
  1107 
  1108 (*------- SRM.test Schalk I, p.68 Nr. 436b *)
  1109 val t = str2term "5*a*(a - b)^^^2*(a + b)^^^3/(7*b*(a - b)^^^3) * 7*b/(a + b)^^^3";
  1110 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1111 if term2str t = "5 * a / (a + -1 * b)"
  1112 then () else error "rational.sml: diff.behav. in norm_Rational_mg 23";
  1113 
  1114 (*------- Schalk I, p.68 Nr. 437a *)
  1115 val t = str2term "(3*a - 4*b) / (4*c+3*e)  *  (3*a+4*b)/(9*a^^^2 - 16*b^^^2)";
  1116 (* raises an exception for unclear reasons:
  1117 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1118 :
  1119 ###  rls: cancel_p on: (9 * a ^^^ 2 + -16 * b ^^^ 2) / (4 * c + 3 * e) /
  1120 (9 * a ^^^ 2 + -16 * b ^^^ 2) 
  1121 exception Div raised
  1122 
  1123 BUT
  1124 val t = str2term 
  1125   ("(9 * a ^^^ 2 + -16 * b ^^^ 2) / (4 * c + 3 * e) /" ^
  1126   "(9 * a ^^^ 2 + -16 * b ^^^ 2)");
  1127 NONE = cancel_p_ thy t;
  1128 
  1129 if term2str t = "1 / (4 * c + 3 * e)" then ()
  1130 else error "rational.sml: diff.behav. in norm_Rational_mg 24";
  1131 *)
  1132 
  1133 "----- S.K. corrected non-termination 060904";
  1134 val t = str2term "(3*a - 4*b) * (3*a+4*b)/((4*c+3*e)*(9*a^^^2 - 16*b^^^2))";
  1135 val SOME (t, _) = rewrite_set_ thy false make_polynomial t;
  1136 if term2str t = 
  1137   "(9 * a ^^^ 2 + -16 * b ^^^ 2) /\n(36 * a ^^^ 2 * c + 27 * a ^^^ 2 * e + -64 * b ^^^ 2 * c +\n -48 * b ^^^ 2 * e)"
  1138 (*"(9 * a ^^^ 2 + -16 * b ^^^ 2) / (36 * a ^^^ 2 * c + 27 * a ^^^ 2 * e + -64 * b ^^^ 2 * c + -48 * b ^^^ 2 * e)"*)
  1139 then () else error "rational.sml: S.K.8..corrected 060904-6";
  1140 
  1141 "----- S.K. corrected non-termination of cancel_p_";
  1142 val t'' = str2term ("(9 * a ^^^ 2 + -16 * b ^^^ 2) /" ^
  1143   "(36 * a^^^2 * c + (27 * a^^^2 * e + (-64 * b^^^2 * c + -48 * b^^^2 * e)))");
  1144 val SOME (t',_) = rewrite_set_ thy false cancel_p t'';
  1145 if term2str t' = "1 / (4 * c + 3 * e)"
  1146 then () else error "rational.sml: diff.behav. in cancel_p S.K.8";
  1147 
  1148 (*------- Schalk I, p.68 Nr. 437b*)
  1149 val t = str2term "(a + b)/(x^^^2 - y^^^2) * ((x - y)^^^2/(a^^^2 - b^^^2))";
  1150 (*val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1151 :
  1152 ####  rls: cancel_p on: (a * x ^^^ 2 + -2 * (a * (x * y)) + a * y ^^^ 2 + b * x ^^^ 2 +
  1153  -2 * (b * (x * y)) +
  1154  b * y ^^^ 2) /
  1155 (a ^^^ 2 * x ^^^ 2 + -1 * (a ^^^ 2 * y ^^^ 2) + -1 * (b ^^^ 2 * x ^^^ 2) +
  1156  b ^^^ 2 * y ^^^ 2) 
  1157 exception Div raised
  1158 *)
  1159 
  1160 (*------- SRM Schalk I, p.68 Nr. 438a *)
  1161 val t = str2term "x*y / (x*y - y^^^2)  *  (x^^^2 - x*y)";
  1162 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1163 if term2str t = "x ^^^ 2"
  1164 then () else error "rational.sml: diff.behav. in norm_Rational_mg 24";
  1165 
  1166 (*------- SRM Schalk I, p.68 Nr. 439b *)
  1167 val t = str2term "(4*x^^^2 + 4*x + 1)  *  ((x^^^2 - 2*x^^^3) / (4*x^^^2 + 2*x))";
  1168 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1169 if term2str t = "(x + -4 * x ^^^ 3) / 2"
  1170 then () else error "rational.sml: diff.behav. in norm_Rational_mg 25";
  1171 
  1172 (*------- SRM Schalk I, p.68 Nr. 440a *)
  1173 val t = str2term "(x^^^2 - 2*x) / (x^^^2 - 3*x)  *  (x - 3)^^^2 / (x^^^2 - 4)";
  1174 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1175 if term2str t = "(-3 + x) / (2 + x)"
  1176 then () else error "rational.sml: diff.behav. in norm_Rational_mg 26";
  1177 
  1178 "----- Schalk I, p.68 Nr. 440b SK11 works since 0707xx";
  1179 val t = str2term "(a^^^3 - 9*a) / (a^^^3*b - a*b^^^3)  *  (a^^^2*b + a*b^^^2) / (a+3)";
  1180 (* WN130911 non-termination for unclear reasons:
  1181 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1182 
  1183 ... ENDS WITH THIS TRACE:
  1184 :
  1185 ###  rls: cancel_p on: (-9 * (a ^^^ 3 * b) + -9 * (a ^^^ 2 * b ^^^ 2) + a ^^^ 5 * b +
  1186  a ^^^ 4 * b ^^^ 2) /
  1187 (a ^^^ 3 * b + -1 * (a * b ^^^ 3)) /
  1188 (3 + a)
  1189 BUT THIS IS CORRECTLY RECOGNISED 
  1190 val t = str2term 
  1191   ("(-9 * (a^^^3 * b) + -9 * (a^^^2 * b^^^2) + a^^^5 * b + a^^^4 * b^^^2)  /" ^
  1192   "(a^^^3 * b + -1 * (a * b^^^3))  /  (3 + (a::real))");
  1193 AS
  1194 NONE = cancel_p_ thy t;
  1195 
  1196 if term2str t = "(-3 * a + a ^^^ 2) / (a + -1 * b)" then ()
  1197 else error "rational.sml: diff.behav. in norm_Rational 27";
  1198 *)
  1199 
  1200 "----- SK12 works since 0707xx";
  1201 val t = str2term "(a^^^3 - 9*a) * (a^^^2*b+a*b^^^2)  /  ((a^^^3*b - a*b^^^3) * (a+3))";
  1202 (* WN130911 non-termination due to non-termination of
  1203   cancel_p_ thy (str2term "(4 + -4 * b ^^^ 2) / (a ^^^ 4 + -2 * (a ^^^ 2 * b ^^^ 2) + b ^^^ 4)")
  1204 
  1205 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1206 if term2str t' = "(-3 * a + a ^^^ 2) / (a + -1 * b)" then ()
  1207 else error "rational.sml: diff.behav. in norm_Rational 28";
  1208 *)
  1209 
  1210 "-------- examples common denominator and multiplication from: Schalk --------";
  1211 "-------- examples common denominator and multiplication from: Schalk --------";
  1212 "-------- examples common denominator and multiplication from: Schalk --------";
  1213 (*------- SRAM Schalk I, p.69 Nr. 441b *)
  1214 val t = str2term "(4*a/3 + 3*b^^^2/a^^^3 + b/(4*a))*(4*b/(3*a))";
  1215 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1216 if term2str t = "(36 * b ^^^ 3 + 3 * a ^^^ 2 * b ^^^ 2 + 16 * a ^^^ 4 * b) / (9 * a ^^^ 4)"
  1217 then () else error "rational.sml: diff.behav. in norm_Rational_mg 28";
  1218 
  1219 (*------- SRAM Schalk I, p.69 Nr. 442b *)
  1220 val t = str2term ("(15*a^^^2/x^^^3 - 5*b^^^4/x^^^2 + 25*c^^^2/x) * " ^
  1221   "(x^^^3/(5*a*b^^^3*c^^^3)) + 1/c^^^3 * (b*x/a - 3*a/b^^^3)");
  1222 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1223 if term2str t = "5 * x ^^^ 2 / (a * b ^^^ 3 * c)"
  1224 then () else error "rational.sml: diff.behav. in norm_Rational_mg 29";
  1225 
  1226 (*------- SRAM Schalk I, p.69 Nr. 443b *)
  1227 val t = str2term "(a/2 + b/3) * (b/3 - a/2)";
  1228 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1229 if term2str t = "(-9 * a ^^^ 2 + 4 * b ^^^ 2) / 36"
  1230 then () else error "rational.sml: diff.behav. in norm_Rational_mg 30";
  1231 
  1232 (*------- SRAM Schalk I, p.69 Nr. 445b *)
  1233 val t = str2term "(a^^^2/9 + 2*a/(3*b) + 4/b^^^2)*(a/3 - 2/b) + 8/b^^^3";
  1234 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1235 if term2str t = "a ^^^ 3 / 27"
  1236 then () else error "rational.sml: diff.behav. in norm_Rational_mg 31";
  1237 
  1238 (*------- SRAM Schalk I, p.69 Nr. 446b *)
  1239 val t = str2term "(x/(5*x + 4*y) - y/(5*x - 4*y) + 1)*(25*x^^^2 - 16*y^^^2)";
  1240 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1241 if term2str t = "30 * x ^^^ 2 + -9 * x * y + -20 * y ^^^ 2"
  1242 then () else error "rational.sml: diff.behav. in norm_Rational_mg 32";
  1243 
  1244 (*------- SRAM Schalk I, p.69 Nr. 449a *)(*Achtung: rechnet ca 8 Sekunden*)
  1245 val t = str2term 
  1246 "(2*x^^^2/(3*y)+x/y^^^2)*(4*x^^^4/(9*y^^^2)+x^^^2/y^^^4)*(2*x^^^2/(3*y) - x/y^^^2)";
  1247 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1248 if term2str t = "(-81 * x ^^^ 4 + 16 * x ^^^ 8 * y ^^^ 4) / (81 * y ^^^ 8)"
  1249 then () else error "rational.sml: diff.behav. in norm_Rational_mg 33";
  1250 
  1251 (*------- SRAM Schalk I, p.69 Nr. 450a *)
  1252 val t = str2term 
  1253 "(4*x/(3*y)+2*y/(3*x))^^^2 - (2*y/(3*x) - 2*x/y)*(2*y/(3*x)+2*x/y)";
  1254 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1255 if term2str t = "(52 * x ^^^ 2 + 16 * y ^^^ 2) / (9 * y ^^^ 2)"
  1256 then () else error "rational.sml: diff.behav. in norm_Rational_mg 34";
  1257 
  1258 (*------- SRAM Schalk I, p.69 Nr. 442b --- abgewandelt*)
  1259 val t = str2term 
  1260   ("(15*a^^^4/(a*x^^^3)  -  5*a*((b^^^4 - 5*c^^^2*x) / x^^^2))  *  " ^
  1261   "(x^^^3/(5*a*b^^^3*c^^^3))   +   a/c^^^3 * (x*(b/a) - 3*b*(a/b^^^4))");
  1262 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1263 if term2str t = "5 * x ^^^ 2 / (b ^^^ 3 * c)"
  1264 then () else error "rational.sml: diff.behav. in norm_Rational_mg 53";
  1265 
  1266 
  1267 "-------- examples double fractions from: Mathematik 1 Schalk ----------------";
  1268 "-------- examples double fractions from: Mathematik 1 Schalk ----------------";
  1269 "-------- examples double fractions from: Mathematik 1 Schalk ----------------";
  1270 "----- SRD Schalk I, p.69 Nr. 454b";
  1271 val t = str2term "((2 - x)/(2*a)) / (2*a/(x - 2))";
  1272 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1273 if term2str t = "(-4 + 4 * x + -1 * x ^^^ 2) / (4 * a ^^^ 2)"
  1274 then () else error "rational.sml: diff.behav. in norm_Rational_mg 35";
  1275 
  1276 "----- SRD Schalk I, p.69 Nr. 455a";
  1277 val t = str2term "(a^^^2 + 1)/(a^^^2 - 1) / ((a+1)/(a - 1))";
  1278 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1279 if term2str t = "(1 + a ^^^ 2) / (1 + 2 * a + a ^^^ 2)" then ()
  1280 else error "rational.sml: diff.behav. in norm_Rational_mg 36";
  1281 
  1282 "----- Schalk I, p.69 Nr. 455b";
  1283 val t = str2term "(x^^^2 - 4)/(y^^^2 - 9)/((2+x)/(3 - y))";
  1284 (* WN130911 non-termination due to non-termination of
  1285   cancel_p_ thy (str2term ("(-12 + 4 * y + 3 * x ^^^ 2 + -1 * (x ^^^ 2 * y)) /" ^
  1286                            "(-18 + -9 * x + 2 * y ^^^ 2 + x * y ^^^ 2)"))
  1287 
  1288 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1289 if term2str t = "(2 + -1 * x) / (3 + y)" then ()
  1290 else error "rational.sml: diff.behav. in norm_Rational_mg 37";
  1291 *)
  1292 
  1293 "----- SK060904-1a non-termination of cancel_p_ ?: worked before 0707xx";
  1294 val t = str2term "(x^^^2 - 4)*(3 - y) / ((y^^^2 - 9)*(2+x))";
  1295 (* WN130911 non-termination due to non-termination of
  1296   cancel_p_ thy (str2term ("(-12 + 4 * y + 3 * x ^^^ 2 + -1 * (x ^^^ 2 * y)) /" ^
  1297                            "(-18 + -9 * x + 2 * y ^^^ 2 + x * y ^^^ 2)"))
  1298 
  1299 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1300 if term2str t = "(2 + -1 * x) / (3 + y)" then ()
  1301 else error "rational.sml: diff.behav. in norm_Rational_mg 37b";
  1302 *)
  1303 
  1304 "----- ?: worked before 0707xx";
  1305 val t = str2term "(3 + -1 * y) / (-9 + y ^^^ 2)";
  1306 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1307 if term2str t = "-1 / (3 + y)"
  1308 then () else error "rational.sml: -1 / (3 + y) norm_Rational";
  1309 
  1310 "----- SRD Schalk I, p.69 Nr. 456b";
  1311 val t = str2term "(b^^^3 - b^^^2) / (b^^^2+b) / (b^^^2 - 1)";
  1312 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1313 if term2str t = "b / (1 + 2 * b + b ^^^ 2)"
  1314 then () else error "rational.sml: diff.behav. in norm_Rational_mg 38";
  1315 
  1316 "----- SRD Schalk I, p.69 Nr. 457b";
  1317 val t = str2term "(16*a^^^2 - 9*b^^^2)/(2*a+3*a*b) / ((4*a+3*b)/(4*a^^^2 - 9*a^^^2*b^^^2))";
  1318 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1319 if term2str t = "8 * a ^^^ 2 + -6 * a * b + -12 * a ^^^ 2 * b + 9 * a * b ^^^ 2"
  1320 then () else error "rational.sml: diff.behav. in norm_Rational_mg 39";
  1321 
  1322 "----- Schalk I, p.69 Nr. 458b works since 0707";
  1323 val t = str2term "(2*a^^^2*x - a^^^2) / (a*x - b*x) / (b^^^2*(2*x - 1) / (x*(a - b)))";
  1324 (*val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1325 :
  1326 ###  rls: cancel_p on: (-1 * a ^^^ 2 + 2 * (a ^^^ 2 * x)) / (a * x + -1 * (b * x)) /
  1327 ((-1 * b ^^^ 2 + 2 * (b ^^^ 2 * x)) / (a * x + -1 * (b * x))) 
  1328 exception Div raised
  1329 
  1330 BUT
  1331 val t = str2term 
  1332   ("(-1 * a ^^^ 2 + 2 * (a ^^^ 2 * x)) / (a * x + -1 * (b * x)) /" ^
  1333   "((-1 * b ^^^ 2 + 2 * (b ^^^ 2 * x)) / (a * x + -1 * (b * x)))");
  1334 NONE = cancel_p_ thy t;
  1335 
  1336 if term2str t = "a ^^^ 2 / b ^^^ 2" then ()
  1337 else error "rational.sml: diff.behav. in norm_Rational_mg 39b";
  1338 *)
  1339 
  1340 "----- SRD Schalk I, p.69 Nr. 459b";
  1341 val t = str2term "(a^^^2 - b^^^2)/(a*b) / (4*(a+b)^^^2/a)";
  1342 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1343 if term2str t = "(a + -1 * b) / (4 * a * b + 4 * b ^^^ 2)" then ()
  1344 else error "rational.sml: diff.behav. in norm_Rational_mg 41";
  1345 
  1346 "----- Schalk I, p.69 Nr. 460b nonterm.SK";
  1347 val t = str2term "(9*(x^^^2 - 8*x + 16) / (4*(y^^^2 - 2*y + 1))) / ((3*x - 12) / (16*y - 16))";
  1348 (*val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1349 exception Div raised
  1350 
  1351 BUT
  1352 val t = str2term 
  1353   ("(144 + -72 * x + 9 * x ^^^ 2) / (4 + -8 * y + 4 * y ^^^ 2) /" ^
  1354   "((-12 + 3 * x) / (-16 + 16 * y))");
  1355 NONE = cancel_p_ thy t;
  1356 
  1357 if term2str t = !!!!!!!!!!!!!!!!!!!!!!!!!
  1358 then () else error "rational.sml: diff.behav. in norm_Rational_mg 42";
  1359 *)
  1360 
  1361 "----- some variant of the above; was non-terminating before";
  1362 val t = str2term "9*(x^^^2 - 8*x+16)*(16*y - 16)/(4*(y^^^2 - 2*y+1)*(3*x - 12))";
  1363 val SOME (t , _) = rewrite_set_ thy false norm_Rational t;
  1364 if term2str t = "(48 + -12 * x) / (1 + -1 * y)"
  1365 then () else error "some variant of the above; was non-terminating before";
  1366 
  1367 "----- SRD Schalk I, p.70 Nr. 472a";
  1368 val t = str2term ("((8*x^^^2 - 32*y^^^2) / (2*x + 4*y))  /  ((4*x - 8*y) / (x + y))");
  1369 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1370 if term2str t = "x + y"
  1371 then () else error "rational.sml: diff.behav. in norm_Rational_mg 43";
  1372 
  1373 "----- Schalk I, p.70 Nr. 478b ----- Rechenzeit: 5 sec";
  1374 val t = str2term ("(a - (a*b + b^^^2)/(a+b))/(b+(a - b)/(1+(a+b)/(a - b))) / " ^
  1375 		 "((a - a^^^2/(a+b))/(a+(a*b)/(a - b)))");
  1376 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1377 if term2str t = "(2 * a ^^^ 3 + 2 * a ^^^ 2 * b) / (a ^^^ 2 * b + b ^^^ 3)"
  1378 then () else error "rational.sml: diff.behav. in norm_Rational_mg 51";
  1379 
  1380 (*SRD Schalk I, p.69 Nr. 461a *)
  1381 val t = str2term "(2/(x+3) + 2/(x - 3)) / (8*x/(x^^^2 - 9))";
  1382 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1383 if term2str t = "1 / 2"
  1384 then () else error "rational.sml: diff.behav. in norm_Rational_mg 44";
  1385 
  1386 (*SRD Schalk I, p.69 Nr. 464b *)
  1387 val t = str2term "(a - a/(a - 2)) / (a + a/(a - 2))";
  1388 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1389 if term2str t = "(-3 + a) / (-1 + a)"
  1390 then () else error "rational.sml: diff.behav. in norm_Rational_mg 45";
  1391 
  1392 (*SRD Schalk I, p.69 Nr. 465b *)
  1393 val t = str2term "((x+3*y)/9 + (4*y^^^2 - 9*z^^^2)/(16*x))   /   (x/9 + y/6 + z/4)";
  1394 (* WN130911 non-termination due to non-termination of
  1395   cancel_p_ thy (str2term 
  1396     ("("(576 * x ^^^ 2 + 1728 * (x * y) + 1296 * y ^^^ 2 + -2916 * z ^^^ 2) /" ^
  1397       "(576 * x ^^^ 2 + 864 * (x * y) + 1296 * (x * z))"))
  1398 
  1399 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1400 if term2str t = "(4 * x + 6 * y + -9 * z) / (4 * x)"
  1401 then () else error "rational.sml: diff.behav. in norm_Rational_mg 46";
  1402 *)
  1403 
  1404 (*SRD Schalk I, p.69 Nr. 466b *)
  1405 val t = str2term "((1 - 7*(x - 2)/(x^^^2 - 4)) / (6/(x+2))) / (3/(x+5)+30/(x^^^2 - 25))";
  1406 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1407 if term2str t = "(25 + -10 * x + x ^^^ 2) / 18"
  1408 then () else error "rational.sml: diff.behav. in norm_Rational_mg 47";
  1409 
  1410 (*SRD Schalk I, p.70 Nr. 469 *)
  1411 val t = str2term ("3*b^^^2 / (4*a^^^2 - 8*a*b + 4*b^^^2) / " ^
  1412   "(a / (a^^^2*b - b^^^3)  +  (a - b) / (4*a*b^^^2 + 4*b^^^3)  -  1 / (4*b^^^2))");
  1413 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1414 if term2str t = "-3 * b ^^^ 3 / (-2 * a + 2 * b)"
  1415 then () else error "rational.sml: diff.behav. in norm_Rational_mg 48";
  1416 
  1417 "-------- me Schalk I No.186 -------------------------------------------------";
  1418 "-------- me Schalk I No.186 -------------------------------------------------";
  1419 "-------- me Schalk I No.186 -------------------------------------------------";
  1420 val fmz = ["Term ((14 * x * y) / ( x * y ))", "normalform N"];
  1421 val (dI',pI',mI') =
  1422   ("Rational",["rational","simplification"],
  1423    ["simplification","of_rationals"]);
  1424 val p = e_pos'; val c = []; 
  1425 val (p,_,f,nxt,_,pt) = CalcTreeTEST [(fmz, (dI',pI',mI'))];
  1426 val (p,_,f,nxt,_,pt) = me nxt p c pt;
  1427 val (p,_,f,nxt,_,pt) = me nxt p c pt;
  1428 val (p,_,f,nxt,_,pt) = me nxt p c pt;
  1429 val (p,_,f,nxt,_,pt) = me nxt p c pt;
  1430 val (p,_,f,nxt,_,pt) = me nxt p c pt;
  1431 val (p,_,f,nxt,_,pt) = me nxt p c pt;
  1432 val (p,_,f,nxt,_,pt) = me nxt p c pt;
  1433 val (p,_,f,nxt,_,pt) = me nxt p c pt; f2str f;
  1434 val (p,_,f,nxt,_,pt) = me nxt p c pt; f2str f;
  1435 val (p,_,f,nxt,_,pt) = me nxt p c pt; f2str f;(*++ for explicit script*)
  1436 val (p,_,f,nxt,_,pt) = me nxt p c pt; f2str f;(*++ for explicit script*)
  1437 case (f2str f, nxt) of
  1438     ("14", ("End_Proof'", _)) => ()
  1439   | _ => error "rational.sml diff.behav. in me Schalk I No.186";
  1440 
  1441 "-------- interSteps ..Simp_Rat_Double_No-1.xml ------------------------------";
  1442 "-------- interSteps ..Simp_Rat_Double_No-1.xml ------------------------------";
  1443 "-------- interSteps ..Simp_Rat_Double_No-1.xml ------------------------------";
  1444 states:=[];
  1445 CalcTree [(["Term (((2 - x)/(2*a)) / (2*a/(x - 2)))", "normalform N"], 
  1446   ("Rational", ["rational", "simplification"], ["simplification", "of_rationals"]))];
  1447 Iterator 1;
  1448 moveActiveRoot 1;
  1449 autoCalculate 1 CompleteCalc;
  1450 val ((pt, p), _) = get_calc 1; 
  1451 (*
  1452 show_pt pt;
  1453 [
  1454 (([], Frm), Simplify ((2 - x) / (2 * a) / (2 * a / (x - 2)))),
  1455 (([1], Frm), (2 - x) / (2 * a) / (2 * a / (x - 2))),
  1456 (([1], Res), (2 + -1 * x) / (2 * a) / (2 * a / (x + -1 * 2))),
  1457 (([2], Res), (2 + -1 * x) / (2 * a) / (2 * a / (-2 + x))),
  1458 (([3], Res), (2 + -1 * x) * (-2 + x) / (2 * a * (2 * a))),
  1459 (([4], Res), (-4 + 4 * x + -1 * x ^^^ 2) / (4 * a ^^^ 2)),
  1460 (([], Res), (-4 + 4 * x + -1 * x ^^^ 2) / (4 * a ^^^ 2))] 
  1461 *)
  1462 interSteps 1 ([1], Res);
  1463 val ((pt, p), _) = get_calc 1; 
  1464 (*show_pt pt;
  1465 [
  1466 (([], Frm), Simplify ((2 - x) / (2 * a) / (2 * a / (x - 2)))),
  1467 (([1], Frm), (2 - x) / (2 * a) / (2 * a / (x - 2))),
  1468 (([1,1], Frm), (2 - x) / (2 * a) / (2 * a / (x - 2))),
  1469 (([1,1], Res), (2 - x) / (2 * a) / (2 * a / (x + -1 * 2))),
  1470 (([1,2], Res), (2 + -1 * x) / (2 * a) / (2 * a / (x + -1 * 2))),
  1471 (([1], Res), (2 + -1 * x) / (2 * a) / (2 * a / (x + -1 * 2))),
  1472 (([2], Res), (2 + -1 * x) / (2 * a) / (2 * a / (-2 + x))),
  1473 (([3], Res), (2 + -1 * x) * (-2 + x) / (2 * a * (2 * a))),
  1474 (([4], Res), (-4 + 4 * x + -1 * x ^^^ 2) / (4 * a ^^^ 2)),
  1475 (([], Res), (-4 + 4 * x + -1 * x ^^^ 2) / (4 * a ^^^ 2))] 
  1476 *)
  1477 val (t, asm) = get_obj g_result pt [1, 1];
  1478 if term2str t = "(2 - x) / (2 * a) / (2 * a / (x + -1 * 2))" andalso terms2str asm = "[]"
  1479 then () else error "2nd interSteps ..Simp_Rat_Double_No-1 changed on [1, 1]";
  1480 val (t, asm) = get_obj g_result pt [1, 2];
  1481 if term2str t = "(2 + -1 * x) / (2 * a) / (2 * a / (x + -1 * 2))" andalso terms2str asm = "[]"
  1482 then () else error "3rd interSteps ..Simp_Rat_Double_No-1 changed on [1, 2]";
  1483 
  1484 
  1485 "-------- interSteps ..Simp_Rat_Cancel_No-1.xml ------------------------------";
  1486 "-------- interSteps ..Simp_Rat_Cancel_No-1.xml ------------------------------";
  1487 "-------- interSteps ..Simp_Rat_Cancel_No-1.xml ------------------------------";
  1488 states:=[];
  1489 CalcTree [(["Term ((a^2 + -1*b^2) / (a^2 + -2*a*b + b^2))", "normalform N"], 
  1490   ("Rational", ["rational", "simplification"], ["simplification", "of_rationals"]))];
  1491 Iterator 1;
  1492 moveActiveRoot 1;
  1493 autoCalculate 1 CompleteCalc;
  1494 val ((pt, p), _) = get_calc 1;
  1495 (*show_pt pt;
  1496 [
  1497 (([], Frm), Simplify ((a ^^^ 2 + -1 * b ^^^ 2) / (a ^^^ 2 + -2 * a * b + b ^^^ 2))),
  1498 (([1], Frm), (a ^^^ 2 + -1 * b ^^^ 2) / (a ^^^ 2 + -2 * a * b + b ^^^ 2)),
  1499 (([1], Res), (a ^^^ 2 + -1 * b ^^^ 2) / (a ^^^ 2 + -2 * (a * b) + b ^^^ 2)),
  1500 (([2], Res), (a + b) / (a + -1 * b)),
  1501 (([], Res), (a + b) / (a + -1 * b))] 
  1502 *)
  1503 interSteps 1 ([2], Res);
  1504 val ((pt, p), _) = get_calc 1;
  1505 (*show_pt pt;
  1506 [
  1507 (([], Frm), Simplify ((a ^^^ 2 + -1 * b ^^^ 2) / (a ^^^ 2 + -2 * a * b + b ^^^ 2))),
  1508 (([1], Frm), (a ^^^ 2 + -1 * b ^^^ 2) / (a ^^^ 2 + -2 * a * b + b ^^^ 2)),
  1509 (([1], Res), (a ^^^ 2 + -1 * b ^^^ 2) / (a ^^^ 2 + -2 * (a * b) + b ^^^ 2)),
  1510 (([2,1], Frm), (a ^^^ 2 + -1 * b ^^^ 2) / (a ^^^ 2 + -2 * (a * b) + b ^^^ 2)),
  1511 (([2,1], Res), (a + b) / (a + -1 * b)),
  1512 (([2], Res), (a + b) / (a + -1 * b)),
  1513 (([], Res), (a + b) / (a + -1 * b))] 
  1514 *)
  1515 interSteps 1 ([2,1],Res);
  1516 val ((pt, p), _) = get_calc 1; 
  1517 (*show_pt pt;
  1518 [
  1519 (([], Frm), Simplify ((a ^^^ 2 + -1 * b ^^^ 2) / (a ^^^ 2 + -2 * a * b + b ^^^ 2))),
  1520 (([1], Frm), (a ^^^ 2 + -1 * b ^^^ 2) / (a ^^^ 2 + -2 * a * b + b ^^^ 2)),
  1521 (([1], Res), (a ^^^ 2 + -1 * b ^^^ 2) / (a ^^^ 2 + -2 * (a * b) + b ^^^ 2)),
  1522 (([2,1], Frm), (a ^^^ 2 + -1 * b ^^^ 2) / (a ^^^ 2 + -2 * (a * b) + b ^^^ 2)),
  1523 (([2,1,1], Frm), (a ^^^ 2 + -1 * b ^^^ 2) / (a ^^^ 2 + -2 * (a * b) + b ^^^ 2)),
  1524 (([2,1,1], Res), (a ^^^ 2 + -1 * (a * b) + a * b + -1 * b ^^^ 2) /
  1525 (a ^^^ 2 + -2 * (a * b) + 1 * b ^^^ 2)),
  1526 (([2,1,2], Res), (a ^^^ 2 + -1 * (a * b) + a * b + -1 * b ^^^ 2) /
  1527 (a ^^^ 2 + -2 * (a * b) + -1 ^^^ 2 * b ^^^ 2)),
  1528 (([2,1,3], Res), (a ^^^ 2 + -1 * (a * b) + a * b + -1 * b ^^^ 2) /
  1529 (a ^^^ 2 + -2 * (a * b) + (-1 * b) ^^^ 2)),
  1530 (([2,1,4], Res), (a * a + -1 * (a * b) + a * b + -1 * b ^^^ 2) /
  1531 (a ^^^ 2 + -2 * (a * b) + (-1 * b) ^^^ 2)),
  1532 (([2,1,5], Res), (a * a + -1 * (a * b) + a * b + -1 * (b * b)) /
  1533 (a ^^^ 2 + -2 * (a * b) + (-1 * b) ^^^ 2)),
  1534 (([2,1,6], Res), (a * a + -1 * (a * b) + a * b + -1 * (b * b)) /
  1535 (a ^^^ 2 + -1 * (2 * (a * b)) + (-1 * b) ^^^ 2)),
  1536 (([2,1,7], Res), (a * a + a * (-1 * b) + (b * a + b * (-1 * b))) /
  1537 (a ^^^ 2 + 2 * (a * (-1 * b)) + (-1 * b) ^^^ 2)),
  1538 (([2,1,8], Res), (a * a + a * (-1 * b) + (b * a + b * (-1 * b))) /
  1539 (a ^^^ 2 + 2 * a * (-1 * b) + (-1 * b) ^^^ 2)),
  1540 (([2,1,9], Res), (a * (a + -1 * b) + (b * a + b * (-1 * b))) /
  1541 (a ^^^ 2 + 2 * a * (-1 * b) + (-1 * b) ^^^ 2)),
  1542 (([2,1,10], Res), (a * (a + -1 * b) + b * (a + -1 * b)) /
  1543 (a ^^^ 2 + 2 * a * (-1 * b) + (-1 * b) ^^^ 2)),
  1544 (([2,1,11], Res), (a + b) * (a + -1 * b) / (a ^^^ 2 + 2 * a * (-1 * b) + (-1 * b) ^^^ 2)),
  1545 (([2,1,12], Res), (a + b) * (a + -1 * b) / ((a + -1 * b) * (a + -1 * b))),
  1546 (([2,1,13], Res), (a + b) / (a + -1 * b)),
  1547 (([2,1], Res), (a + b) / (a + -1 * b)),
  1548 (([2], Res), (a + b) / (a + -1 * b)),
  1549 (([], Res), (a + b) / (a + -1 * b))] 
  1550 *)
  1551 val newnds = children (get_nd pt [2,1]) (*see "fun detailrls"*);
  1552 if length newnds = 13 then () else error "rational.sml: interSteps cancel_p rev_rew_p";
  1553 
  1554 val p = ([2,1,9],Res);
  1555 getTactic 1 p;
  1556 val (_, tac, _) = pt_extract (pt, p);
  1557 case tac of SOME (Rewrite ("sym_distrib_left", _)) => ()
  1558 | _ => error "rational.sml: getTactic, sym_real_plus_binom_times1";
  1559 
  1560 
  1561 "-------- investigate rulesets for cancel_p ----------------------------------";
  1562 "-------- investigate rulesets for cancel_p ----------------------------------";
  1563 "-------- investigate rulesets for cancel_p ----------------------------------";
  1564 val thy = @{theory "Rational"};
  1565 val t = str2term "(a^^^2 + -1*b^^^2) / (a^^^2 + -2*a*b + b^^^2)";
  1566 val tt = str2term "(1 * a + 1 * b) * (1 * a + -1 * b)"(*numerator only*);
  1567 
  1568 "----- with rewrite_set_";
  1569 val SOME (tt',asm) = rewrite_set_ thy false make_polynomial tt;
  1570 if term2str tt'= "a ^^^ 2 + -1 * b ^^^ 2" then () else error "rls chancel_p 1";
  1571 val tt = str2term "((1 * a + -1 * b) * (1 * a + -1 * b))"(*denominator only*);
  1572 val SOME (tt',asm) = rewrite_set_ thy false make_polynomial tt;
  1573 if term2str tt' = "a ^^^ 2 + -2 * a * b + b ^^^ 2" then () else error "rls chancel_p 2";
  1574 
  1575 "----- with make_deriv; WN1130912 not investigated further, will be discontinued";
  1576 val SOME (tt, _) = factout_p_ thy t; 
  1577 if term2str tt = "(a + b) * (a + -1 * b) / ((a + -1 * b) * (a + -1 * b))"
  1578 then () else error "rls chancel_p 3";
  1579 term2str tt = "(1 * a + 1 * b) * (1 * a + -1 * b) / ((1 * a + -1 * b) * (1 * a + -1 * b))";
  1580 
  1581 "--- with simpler ruleset";
  1582 val {rules, rew_ord= (_, ro), ...} = rep_rls (assoc_rls "rev_rew_p");
  1583 val der = make_deriv thy Atools_erls rules ro NONE tt;
  1584 if length der = 12 then () else error "WN1130912 rls chancel_p 4";
  1585 print_depth 99; writeln (deriv2str der); print_depth 3;
  1586 
  1587 print_depth 99; map (term2str o #1) der; print_depth 3;
  1588 "...,(-1 * b ^^^ 2 + a ^^^ 2) / (-2 * (a * b) + a ^^^ 2 + (-1 * b) ^^^ 2) ]";
  1589 print_depth 99; map (rule2str o #2) der; print_depth 3;
  1590 print_depth 99; map (term2str o #1 o #3) der; print_depth 3;
  1591 
  1592 val der = make_deriv thy Atools_erls rules ro NONE 
  1593 	(str2term "(1 * a + 1 * b) * (1 * a + -1 * b)");
  1594 print_depth 99; writeln (deriv2str der); print_depth 3;
  1595 
  1596 val {rules, rew_ord=(_,ro),...} = rep_rls (assoc_rls "rev_rew_p");
  1597 val der = make_deriv thy Atools_erls rules ro NONE 
  1598 	(str2term "(1 * a + -1 * b) * (1 * a + -1 * b)");
  1599 print_depth 99; writeln (deriv2str der); print_depth 3;
  1600 print_depth 99; map (term2str o #1) der; print_depth 3;
  1601 (*WN060829 ...postponed*)
  1602 
  1603 
  1604 "-------- fun eval_get_denominator -------------------------------------------";
  1605 "-------- fun eval_get_denominator -------------------------------------------";
  1606 "-------- fun eval_get_denominator -------------------------------------------";
  1607 val thy = @{theory Isac};
  1608 val t = term_of (the (parse thy "get_denominator ((a +x)/b)"));
  1609 val SOME (_, t') = eval_get_denominator "" 0 t thy;
  1610 if term2str t' = "get_denominator ((a + x) / b) = b"
  1611 then () else error "get_denominator ((a + x) / b) = b"
  1612 
  1613 
  1614 "-------- several errpats in complicated term --------------------------------";
  1615 "-------- several errpats in complicated term --------------------------------";
  1616 "-------- several errpats in complicated term --------------------------------";
  1617 (*WN12xxxx TODO: instead of Gabriella's example here (27.Jul.12) find a simpler one
  1618   WN130912: kept this test, although not clear what for*)
  1619 states := [];
  1620 CalcTree [(["Term ((5*b + 25)/(a^2 - b^2) * (a - b)/(5*b))", "normalform N"], 
  1621   ("Rational", ["rational", "simplification"], ["simplification", "of_rationals"]))];
  1622 Iterator 1;
  1623 moveActiveRoot 1;
  1624 autoCalculate 1 CompleteCalc;
  1625 val ((pt, p), _) = get_calc 1;
  1626 (*show_pt pt;
  1627 [
  1628 (([], Frm), Simplify ((5 * b + 25) / (a ^^^ 2 - b ^^^ 2) * (a - b) / (5 * b))),
  1629 (([1], Frm), (5 * b + 25) / (a ^^^ 2 - b ^^^ 2) * (a - b) / (5 * b)),
  1630 (([1], Res), (5 * b + 25) / (a ^^^ 2 + -1 * b ^^^ 2) * (a + -1 * b) / (5 * b)),
  1631 (([2], Res), (5 * b + 25) * (a + -1 * b) / (a ^^^ 2 + -1 * b ^^^ 2) / (5 * b)),
  1632 (([3], Res), (25 * a + -25 * b + 5 * (a * b) + -5 * b ^^^ 2) / (a ^^^ 2 + -1 * b ^^^ 2) /
  1633 (5 * b)),
  1634 (([4], Res), (25 + 5 * b) / (a + b) / (5 * b)),
  1635 (([5], Res), (25 + 5 * b) / ((a + b) * (5 * b))),
  1636 (([6], Res), (25 + 5 * b) / (5 * (a * b) + 5 * b ^^^ 2)),
  1637 (([7], Res), (5 + b) / (a * b + b ^^^ 2)),
  1638 (([], Res), (5 + b) / (a * b + b ^^^ 2))] *)
  1639 
  1640 
  1641