test/Tools/isac/Knowledge/rational.sml
changeset 52105 2786cc9704c8
parent 52104 83166e7c7e52
child 52106 7f3760f39bdc
equal deleted inserted replaced
52104:83166e7c7e52 52105:2786cc9704c8
    15 "-------- integration lev.1 fun common_nominator_p_ --------------------------";
    15 "-------- integration lev.1 fun common_nominator_p_ --------------------------";
    16 "-------- integration lev.1 fun add_fraction_p_ ------------------------------";
    16 "-------- integration lev.1 fun add_fraction_p_ ------------------------------";
    17 "-------- and app_rev ...traced down from rewrite_set_ until prepats ---------";
    17 "-------- and app_rev ...traced down from rewrite_set_ until prepats ---------";
    18 "-------- fun rewrite_set_ cancel_p downto fun gcd_poly ----------------------";
    18 "-------- fun rewrite_set_ cancel_p downto fun gcd_poly ----------------------";
    19 "-------- rls norm_Rational downto fun gcd_poly ------------------------------";
    19 "-------- rls norm_Rational downto fun gcd_poly ------------------------------";
       
    20 "-------- rls norm_Rational downto fun add_fraction_p_ -----------------------";
    20 "-------- rewrite_set_ cancel_p from: Mathematik 1 Schalk Reniets Verlag -----";
    21 "-------- rewrite_set_ cancel_p from: Mathematik 1 Schalk Reniets Verlag -----";
    21 "-------- rewrite_set_ common_nominator_p from: Mathematik 1 Schalk ----------";
    22 "-------- rewrite_set_ add_fractions_p from: Mathematik 1 Schalk -------------";
    22 "-------- integration lev.1 -- lev.5: cancel_p_ & common_nominator_p_ --------";
    23 "-------- integration lev.1 -- lev.5: cancel_p_ & add_fractions_p_ -----------";
    23 "-------- reverse rewrite ----------------------------------------------------";
    24 "-------- reverse rewrite ----------------------------------------------------";
    24 "-------- 'reverse-ruleset' cancel_p -----------------------------------------";
    25 "-------- 'reverse-ruleset' cancel_p -----------------------------------------";
    25 "-------- investigate rls norm_Rational --------------------------------------";
    26 "-------- investigate rls norm_Rational --------------------------------------";
    26 "-------- examples: rls norm_Rational ----------------------------------------";
    27 "-------- examples: rls norm_Rational ----------------------------------------";
    27 "-------- numeral rationals -----------------------------";
    28 "-------- rational numerals --------------------------------------------------";
    28 "-------- cancellation ----------------------------------";
    29 "-------- examples cancellation from: Mathematik 1 Schalk --------------------";
    29 "-------- common denominator ----------------------------";
    30 "-------- examples common denominator from: Mathematik 1 Schalk --------------";
    30 "-------- multiply and cancel ---------------------------";
    31 "-------- examples multiply and cancel from: Mathematik 1 Schalk -------------";
    31 "-------- common denominator and multiplication ---------";
    32 "-------- examples common denominator and multiplication from: Schalk --------";
    32 "-------- double fractions ------------------------------";
    33 "-------- examples double fractions from: Mathematik 1 Schalk ----------------";
    33 "-------- crucial examples ------------------------------";
    34 "-------- me Schalk I No.186 -------------------------------------------------";
    34 "-------- examples for Stefan Karnels thesis ------------";
    35 "-------- interSteps ..Simp_Rat_Double_No-1.xml ------------------------------";
    35 "-------- me Schalk I No.186 ----------------------------";
    36 "-------- interSteps ..Simp_Rat_Cancel_No-1.xml ------------------------------";
    36 "-------- interSteps ..Simp_Rat_Double_No-1.xml ---------";
    37 "-------- investigate rulesets for cancel_p ----------------------------------";
    37 "-------- interSteps ..Simp_Rat_Cancel_No-1.xml ---------";
    38 "-------- fun eval_get_denominator -------------------------------------------";
    38 "-------- investigate rulesets for cancel_p -------------";
    39 "-------- several errpats in complicated term --------------------------------";
    39 "-------- investigate format of factout_ and factout_p_ -";
    40 "-----------------------------------------------------------------------------";
    40 "-------- how to stepwise construct Scripts -------------";
    41 "-----------------------------------------------------------------------------";
    41 "----------- get_denominator ----------------------------";
       
    42 "--------- several errpats in complicated term -------------------";
       
    43 "--------------------------------------------------------";
       
    44 "-------- nonterminating cancel_p, norm_Rational 2002 ---";
       
    45 "--------------------------------------------------------";
       
    46 "--------------------------------------------------------";
       
    47 
    42 
    48 
    43 
    49 "-------- fun poly_of_term ---------------------------------------------------";
    44 "-------- fun poly_of_term ---------------------------------------------------";
    50 "-------- fun poly_of_term ---------------------------------------------------";
    45 "-------- fun poly_of_term ---------------------------------------------------";
    51 "-------- fun poly_of_term ---------------------------------------------------";
    46 "-------- fun poly_of_term ---------------------------------------------------";
   225                if f pp then true else scan_ f pps;
   220                if f pp then true else scan_ f pps;
   226         in scan_ chk prepat end;
   221         in scan_ chk prepat end;
   227     (* apply the normal_form of a rev-set *)
   222     (* apply the normal_form of a rev-set *)
   228     fun app_rev' thy (Rrls{erls,prepat,scr=Rfuns{normal_form,...},...}) t =
   223     fun app_rev' thy (Rrls{erls,prepat,scr=Rfuns{normal_form,...},...}) t =
   229       if chk_prepat thy erls prepat t
   224       if chk_prepat thy erls prepat t
   230       then ((*tracing("### app_rev': t = "^(term2str t));*) normal_form t)
   225       then ((*tracing("### app_rev': t = "^term2str t);*) normal_form t)
   231       else NONE;
   226       else NONE;
   232 (*  val opt = app_rev' thy rrls t  ..NONE!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!*)
   227 (*  val opt = app_rev' thy rrls t  ..NONE!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!*)
   233 "~~~~~ and app_rev', args:"; val (thy, (Rrls{erls,prepat,scr=Rfuns{normal_form,...},...}), t) =
   228 "~~~~~ and app_rev', args:"; val (thy, (Rrls{erls,prepat,scr=Rfuns{normal_form,...},...}), t) =
   234   (thy, rrls, t);
   229   (thy, rrls, t);
   235 (* chk_prepat thy erls prepat t = false!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!*)
   230 (* chk_prepat thy erls prepat t = false!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!*)
   361         val ((a', b'), c) = gcd_poly a b
   356         val ((a', b'), c) = gcd_poly a b
   362 val a = [(~12, [0, 0]), (3, [2, 0]), (4, [0, 1]), (~1, [2, 1])]: poly
   357 val a = [(~12, [0, 0]), (3, [2, 0]), (4, [0, 1]), (~1, [2, 1])]: poly
   363 val b = [(~18, [0, 0]), (~9, [1, 0]), (2, [0, 2]), (1, [1, 2])]: poly
   358 val b = [(~18, [0, 0]), (~9, [1, 0]), (2, [0, 2]), (1, [1, 2])]: poly
   364 *)
   359 *)
   365 
   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 
   366 "-------- rewrite_set_ cancel_p from: Mathematik 1 Schalk Reniets Verlag -----";
   425 "-------- rewrite_set_ cancel_p from: Mathematik 1 Schalk Reniets Verlag -----";
   367 "-------- rewrite_set_ cancel_p from: Mathematik 1 Schalk Reniets Verlag -----";
   426 "-------- rewrite_set_ cancel_p from: Mathematik 1 Schalk Reniets Verlag -----";
   368 "-------- rewrite_set_ cancel_p from: Mathematik 1 Schalk Reniets Verlag -----";
   427 "-------- rewrite_set_ cancel_p from: Mathematik 1 Schalk Reniets Verlag -----";
   369 val thy  = @{theory "Rational"};
   428 val thy  = @{theory "Rational"};
   370 "-------- WN";
   429 "-------- WN";
   426 val SOME (t', asm) = rewrite_set_ thy false cancel_p t;
   485 val SOME (t', asm) = rewrite_set_ thy false cancel_p t;
   427 if (term2str t', terms2str asm) = ("8 / 9", "[]")
   486 if (term2str t', terms2str asm) = ("8 / 9", "[]")
   428 then () else error "rational.sml cancel Schalk 188a";
   487 then () else error "rational.sml cancel Schalk 188a";
   429 
   488 
   430 val t = str2term "(8*((-1) + x))/(9*((-1) + x))";
   489 val t = str2term "(8*((-1) + x))/(9*((-1) + x))";
   431 val SOME (t,_) = rewrite_set_ thy false make_polynomial t;
   490 val SOME (t, _) = rewrite_set_ thy false make_polynomial t;
   432 if (term2str t', terms2str asm) = ("8 / 9", "[]")
   491 if (term2str t', terms2str asm) = ("8 / 9", "[]")
   433 then () else error "rational.sml cancel Schalk make_polynomial 1";
   492 then () else error "rational.sml cancel Schalk make_polynomial 1";
   434 
   493 
   435 "-------- example 188b";
   494 "-------- example 188b";
   436 val t = str2term "(-15 + 5 * x) / (-18 + 6 * x)";
   495 val t = str2term "(-15 + 5 * x) / (-18 + 6 * x)";
   538 val SOME (t', asm) = rewrite_set_ thy false cancel_p t;
   597 val SOME (t', asm) = rewrite_set_ thy false cancel_p t;
   539 if (term2str t', terms2str asm) = 
   598 if (term2str t', terms2str asm) = 
   540   ("(x ^^^ 3 + y) / (1 + 5 * x + x * y ^^^ 3)", "[\"1 + 5 * x + x * y ^^^ 3 ~= 0\"]")
   599   ("(x ^^^ 3 + y) / (1 + 5 * x + x * y ^^^ 3)", "[\"1 + 5 * x + x * y ^^^ 3 ~= 0\"]")
   541 then () else error "rational.sml cancel_p heuberger";
   600 then () else error "rational.sml cancel_p heuberger";
   542 
   601 
   543 "-------- rewrite_set_ common_nominator_p from: Mathematik 1 Schalk ----------";
   602 "-------- rewrite_set_ add_fractions_p from: Mathematik 1 Schalk -------------";
   544 "-------- rewrite_set_ common_nominator_p from: Mathematik 1 Schalk ----------";
   603 "-------- rewrite_set_ add_fractions_p from: Mathematik 1 Schalk -------------";
   545 "-------- rewrite_set_ common_nominator_p from: Mathematik 1 Schalk ----------";
   604 "-------- rewrite_set_ add_fractions_p from: Mathematik 1 Schalk -------------";
   546 (*deleted example 204 ... 236b at update Isabelle2012-->2013*)
   605 (*deleted example 204 ... 236b at update Isabelle2012-->2013*)
   547 
   606 
   548 "-------- integration lev.1 -- lev.5: cancel_p_ & common_nominator_p_ --------";
   607 "-------- integration lev.1 -- lev.5: cancel_p_ & add_fractions_p_ -----------";
   549 "-------- integration lev.1 -- lev.5: cancel_p_ & common_nominator_p_ --------";
   608 "-------- integration lev.1 -- lev.5: cancel_p_ & add_fractions_p_ -----------";
   550 "-------- integration lev.1 -- lev.5: cancel_p_ & common_nominator_p_ --------";
   609 "-------- integration lev.1 -- lev.5: cancel_p_ & add_fractions_p_ -----------";
   551 val t = str2term ("123 = (a*x)/(b*x) + (c*x)/(d*x) + (e*x)/(f*x::real)");
   610 val t = str2term ("123 = (a*x)/(b*x) + (c*x)/(d*x) + (e*x)/(f*x::real)");
   552 "-------- gcd_poly integration level 1: works on exact term";
   611 "-------- gcd_poly integration level 1: works on exact term";
   553 if NONE = cancel_p_ thy t then () else error "cancel_p_ works on exact fraction";
   612 if NONE = cancel_p_ thy t then () else error "cancel_p_ works on exact fraction";
   554 if NONE = add_fraction_p_ thy t then () else error "add_fraction_p_ works on exact fraction";
   613 if NONE = add_fraction_p_ thy t then () else error "add_fraction_p_ works on exact fraction";
   555 
   614 
   563 
   622 
   564 "-------- gcd_poly integration level 3: rewrites all appropriate subterms";
   623 "-------- gcd_poly integration level 3: rewrites all appropriate subterms";
   565 val SOME (t', asm) = rewrite_set_ thy false cancel_p_rls t;
   624 val SOME (t', asm) = rewrite_set_ thy false cancel_p_rls t;
   566 if term2str t' = "123 = a / b + c / d + e / f"
   625 if term2str t' = "123 = a / b + c / d + e / f"
   567 then () else error "level 3, rewrite_set_ cancel_p_rls: changed";
   626 then () else error "level 3, rewrite_set_ cancel_p_rls: changed";
   568 val SOME (t', asm) = rewrite_set_ thy false common_nominator_p_rls t; (*CREATE add_fractions_p_rls*)
   627 val SOME (t', asm) = rewrite_set_ thy false add_fractions_p_rls t; (*CREATE add_fractions_p_rls*)
   569 if term2str t' = "123 = (b * d * e * x + b * c * f * x + a * d * f * x) / (b * d * f * x)"
   628 if term2str t' = "123 = (b * d * e * x + b * c * f * x + a * d * f * x) / (b * d * f * x)"
   570 then () else error "level 3, rewrite_set_ add_fractions_p_rls: changed";
   629 then () else error "level 3, rewrite_set_ add_fractions_p_rls: changed";
   571 
   630 
   572 "-------- gcd_poly integration level 4: iteration cancel_p -- add_fraction_p";
   631 "-------- gcd_poly integration level 4: iteration cancel_p -- add_fraction_p";
   573 (* simpler variant *)
   632 (* simpler variant *)
   574 val testrls = append_rls "testrls" e_rls [Rls_ cancel_p, Rls_ add_fractions_p]
   633 val testrls = append_rls "testrls" e_rls [Rls_ cancel_p, Rls_ add_fractions_p]
   575 val SOME (t', asm) = rewrite_set_ thy false testrls t;
   634 val SOME (t', asm) = rewrite_set_ thy false testrls t;
   576 (*trace_rewrite := false;
   635 (*trace_rewrite := false;
   577 #  rls: testrls on: 123 = a * x / (b * x) + c * x / (d * x) + e * x / (f * x) 
   636 #  rls: testrls on: 123 = a * x / (b * x) + c * x / (d * x) + e * x / (f * x) 
   578 ##  rls: cancel_p 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) 
   579 ##  rls: common_nominator_p on: 123 = a * x / (b * x) + c * x / (d * x) + e / f 
   638 ##  rls: add_fractions_p on: 123 = a * x / (b * x) + c * x / (d * x) + e / f 
   580 ##  rls: cancel_p on: 123 = (b * c * x + a * d * x) / (b * d * x) + e / f 
   639 ##  rls: cancel_p on: 123 = (b * c * x + a * d * x) / (b * d * x) + e / f 
   581 ##  rls: common_nominator_p on: 123 = (b * c + a * d) / (b * d) + e / f 
   640 ##  rls: add_fractions_p on: 123 = (b * c + a * d) / (b * d) + e / f 
   582 ##  rls: cancel_p on: 123 = (b * d * e + b * c * f + a * d * f) / (b * d * f) 
   641 ##  rls: cancel_p on: 123 = (b * d * e + b * c * f + a * d * f) / (b * d * f) 
   583 ##  rls: common_nominator_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) *)
   584 if term2str t' = "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)"
   585 then () else error "level 4, rewrite_set_ *_p: changed";
   644 then () else error "level 4, rewrite_set_ *_p: changed";
   586 
   645 
   587 (* complicated variant *)
   646 (* complicated variant *)
   588 val testrls_rls = append_rls "testrls_rls" e_rls [Rls_ cancel_p_rls, Rls_ common_nominator_p_rls];
   647 val testrls_rls = append_rls "testrls_rls" e_rls [Rls_ cancel_p_rls, Rls_ add_fractions_p_rls];
   589 val SOME (t', asm) = rewrite_set_ thy false testrls_rls t;
   648 val SOME (t', asm) = rewrite_set_ thy false testrls_rls t;
   590 (*#  rls: testrls_rls on: 123 = a * x / (b * x) + c * x / (d * x) + e * x / (f * x) 
   649 (*#  rls: testrls_rls on: 123 = a * x / (b * x) + c * x / (d * x) + e * x / (f * x) 
   591 ##  rls: cancel_p_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) 
   592 ###  rls: cancel_p 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) 
   593 ###  rls: cancel_p on: 123 = a * x / (b * x) + c * x / (d * x) + e / f 
   652 ###  rls: cancel_p on: 123 = a * x / (b * x) + c * x / (d * x) + e / f 
   594 ###  rls: cancel_p on: 123 = a * x / (b * x) + c / d + e / f 
   653 ###  rls: cancel_p on: 123 = a * x / (b * x) + c / d + e / f 
   595 ###  rls: cancel_p on: 123 = a / b + c / d + e / f 
   654 ###  rls: cancel_p on: 123 = a / b + c / d + e / f 
   596 ##  rls: common_nominator_p_rls on: 123 = a / b + c / d + e / f 
   655 ##  rls: add_fractions_p_rls on: 123 = a / b + c / d + e / f 
   597 ###  rls: common_nominator_p on: 123 = a / b + c / d + e / f 
   656 ###  rls: add_fractions_p on: 123 = a / b + c / d + e / f 
   598 ###  rls: common_nominator_p on: 123 = (b * c + a * d) / (b * d) + e / f 
   657 ###  rls: add_fractions_p on: 123 = (b * c + a * d) / (b * d) + e / f 
   599 ###  rls: common_nominator_p on: 123 = (b * d * e + b * c * f + a * d * f) / (b * d * f) 
   658 ###  rls: add_fractions_p on: 123 = (b * d * e + b * c * f + a * d * f) / (b * d * f) 
   600 ##  rls: cancel_p_rls 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) 
   601 ###  rls: cancel_p 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) 
   602 ##  rls: common_nominator_p_rls 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) 
   603 ###  rls: common_nominator_p 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) *)
   604 if term2str t' = "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)"
   605 then () else error "level 4, rewrite_set_ *_p_rls: changed"
   664 then () else error "level 4, rewrite_set_ *_p_rls: changed"
   606 
   665 
   607 "-------- gcd_poly integration level 5: cancel_p & add_fraction_p within norm_Rational";
   666 "-------- gcd_poly integration level 5: cancel_p & add_fraction_p within norm_Rational";
   608 val SOME (t', asm) = rewrite_set_ thy false norm_Rational t;
   667 val SOME (t', asm) = rewrite_set_ thy false norm_Rational t;
   643 (revsets |> nth 1 |> nth 7 |> rule2str) = 
   702 (revsets |> nth 1 |> nth 7 |> rule2str) = 
   644   "Thm (\"sym_mult_assoc\",Groups.semigroup_mult_class.mult_assoc)"
   703   "Thm (\"sym_mult_assoc\",Groups.semigroup_mult_class.mult_assoc)"
   645 then () else error "first 7 elements in revset changed"
   704 then () else error "first 7 elements in revset changed"
   646 
   705 
   647 (** find the rule 'r' to apply to term 't' **)
   706 (** find the rule 'r' to apply to term 't' **)
   648 (*/------- since cancel_ (accepted "-" between monomials) has been replaced by cancel_p_ 
   707 (*/------- WN1309: since cancel_ (accepted "-" between monomials) has been replaced by cancel_p_ 
   649   for Isabelle2013, we don't get a working revset, but non-termination:
   708   for Isabelle2013, we don't get a working revset, but non-termination:
   650 
   709 
   651   val SOME (r as (Thm (str, thm))) = nex revsets t;
   710   val SOME (r as (Thm (str, thm))) = nex revsets t;
   652   :
   711   :
   653 ((3 * 3 + -1 * x * x) / (3 * 3 + 2 * 3 * x + x * x), 
   712 ((3 * 3 + -1 * x * x) / (3 * 3 + 2 * 3 * x + x * x), 
   715 \--------------------------------------------------------------------------------------/*)
   774 \--------------------------------------------------------------------------------------/*)
   716 
   775 
   717 "-------- 'reverse-ruleset' cancel_p -----------------------------------------";
   776 "-------- 'reverse-ruleset' cancel_p -----------------------------------------";
   718 "-------- 'reverse-ruleset' cancel_p -----------------------------------------";
   777 "-------- 'reverse-ruleset' cancel_p -----------------------------------------";
   719 "-------- 'reverse-ruleset' cancel_p -----------------------------------------";
   778 "-------- 'reverse-ruleset' cancel_p -----------------------------------------";
   720 (*Isabelle2013: the example below shows, why "reverse rewriting" only worked for
   779 (*WN130909: the example below shows, why "reverse rewriting" only worked for
   721   special cases.*)
   780   special cases.*)
   722 
   781 
   723 (*the term for which reverse rewriting is demonstrated*)
   782 (*the term for which reverse rewriting is demonstrated*)
   724 val t = str2term "(9 + (-1)*x^^^2) / (9 + ((-6)*x + x^^^2))";
   783 val t = str2term "(9 + (-1)*x^^^2) / (9 + ((-6)*x + x^^^2))";
   725 val Rrls {scr=Rfuns {init_state=ini,locate_rule=loc,
   784 val Rrls {scr=Rfuns {init_state=ini,locate_rule=loc,
   753   val SOME r = nex revsets t;
   812   val SOME r = nex revsets t;
   754   val (r,(t,asm))::_ = loc revsets t r;
   813   val (r,(t,asm))::_ = loc revsets t r;
   755   term2str t;
   814   term2str t;
   756 *)                    
   815 *)                    
   757 
   816 
   758 (*========== inhibit exn WN130824 TODO =======================================================
       
   759 "-------- examples: rls norm_Rational ----------------------------------------";
   817 "-------- examples: rls norm_Rational ----------------------------------------";
   760 "-------- examples: rls norm_Rational ----------------------------------------";
   818 "-------- examples: rls norm_Rational ----------------------------------------";
   761 "-------- examples: rls norm_Rational ----------------------------------------";
   819 "-------- examples: rls norm_Rational ----------------------------------------";
   762 val t = str2term "(3*x+5)/18 - x/2  - -(3*x - 2)/9 = 0";
   820 val t = str2term "(3*x+5)/18 - x/2  - -(3*x - 2)/9 = 0";
   763 val SOME (t',_) = rewrite_set_ thy false norm_Rational t; term2str t';
   821 val SOME (t',_) = rewrite_set_ thy false norm_Rational t; term2str t';
   791 val SOME (t',_) = rewrite_set_ thy false norm_Rational t; term2str t';
   849 val SOME (t',_) = rewrite_set_ thy false norm_Rational t; term2str t';
   792 if term2str t' = "65 * x / 2" then () else error "rational.sml 4";
   850 if term2str t' = "65 * x / 2" then () else error "rational.sml 4";
   793 
   851 
   794 val t = str2term "1 - ((13*x)/2 - 5/2)^^^2";
   852 val t = str2term "1 - ((13*x)/2 - 5/2)^^^2";
   795 val SOME (t',_) = rewrite_set_ thy false norm_Rational t; term2str t';
   853 val SOME (t',_) = rewrite_set_ thy false norm_Rational t; term2str t';
   796 (*bef.040209: if term2str t' = "(-21 + (130 * x + -169 * x ^^^ 2)) / 4"then()*)
       
   797 if term2str t' = "(-21 + 130 * x + -169 * x ^^^ 2) / 4" then () 
   854 if term2str t' = "(-21 + 130 * x + -169 * x ^^^ 2) / 4" then () 
   798 else error "rational.sml 5";
   855 else error "rational.sml 5";
   799 
   856 
   800 (*SRAM Schalk I, p.92 Nr. 609a*)
   857 (*SRAM Schalk I, p.92 Nr. 609a*)
   801 val t = str2term "2*(3 - x/5)/3 - 4*(1 - x/3) - x/3 - 2*(x/2 - 1/4)/27 +5/54";
   858 val t = str2term "2*(3 - x/5)/3 - 4*(1 - x/3) - x/3 - 2*(x/2 - 1/4)/27 +5/54";
   810 
   867 
   811 (*SRAM Schalk I, p.92 Nr. 476a*)
   868 (*SRAM Schalk I, p.92 Nr. 476a*)
   812 val t = str2term "(x^^^2/(1 - x^^^2) + 1)/(x/(1 - x) + 1) * (1 + x)";
   869 val t = str2term "(x^^^2/(1 - x^^^2) + 1)/(x/(1 - x) + 1) * (1 + x)";
   813 (*. a/b : c/d translated to a/b * d/c .*)
   870 (*. a/b : c/d translated to a/b * d/c .*)
   814 val SOME (t',_) = rewrite_set_ thy false norm_Rational t; term2str t';
   871 val SOME (t',_) = rewrite_set_ thy false norm_Rational t; term2str t';
   815 (*if term2str t' = "1 / 1" then () else error "rational.sml 8";3.6.03*)
       
   816 if term2str t' = "1" then () else error "rational.sml 8";
   872 if term2str t' = "1" then () else error "rational.sml 8";
   817 
   873 
   818 (*............................vvv---TODO: sollte gehen mit poly_order *)
       
   819 (*Schalk I, p.92 Nr. 472a*)
   874 (*Schalk I, p.92 Nr. 472a*)
   820 val t = str2term "((8*x^^^2 - 32*y^^^2)/(2*x + 4*y))/((4*x - 8*y)/(x + y))";
   875 val t = str2term "((8*x^^^2 - 32*y^^^2)/(2*x + 4*y))/((4*x - 8*y)/(x + y))";
   821 val SOME (t',_) = rewrite_set_ thy false norm_Rational t; term2str t';
   876 val SOME (t',_) = rewrite_set_ thy false norm_Rational t; term2str t';
   822 if term2str t' = "x + y" then () else error "rational.sml p.92 Nr. 472a";
   877 if term2str t' = "x + y" then () else error "rational.sml p.92 Nr. 472a";
   823 
   878 
   824 (*Schalk I, p.70 Nr. 480b; a/b : c/d translated to a/b * d/c*)
   879 (*Schalk I, p.70 Nr. 480b: SEE rational.sml --- nonterminating rls norm_Rational ---*)
   825 val t = str2term ("((12*x*y/(9*x^^^2 - y^^^2))/" ^
   880 
   826 		 "(1/(3*x - y)^^^2 - 1/(3*x + y)^^^2)) *" ^
   881 (*WN130910 add_fractions_p exception Div raised + history:
   827 		 "(1/(x - 5*y)^^^2 - 1/(x + 5*y)^^^2)/" ^
   882 ### WN.2.6.03 from rlang.sml 56a 
   828 		 "(20*x*y/(x^^^2 - 25*y^^^2))");
       
   829 (*... nicht simpl, zerlegt ...*)
       
   830 val t = str2term ("((12*x*y/(9*x^^^2 - y^^^2))/" ^
       
   831 		 "(1/(3*x - y)^^^2 - 1/(3*x + y)^^^2))");
       
   832 val SOME (t',_) = rewrite_set_ thy false norm_Rational t; term2str t';
       
   833 "(-12 * (x * y ^^^ 3) + 108 * (x * (y * x ^^^ 2))) / (12 * (x * y))";
       
   834 (*                             ~~~~~~~~~~ poly_order notwendig!*)
       
   835 val t = str2term ("(1/(x - 5*y)^^^2 - 1/(x + 5*y)^^^2)/" ^
       
   836 		 "(20*x*y/(x^^^2 - 25*y^^^2))");
       
   837 val SOME (t',_) = rewrite_set_ thy false norm_Rational t; term2str t';
       
   838 if term2str t' = "1 / (x ^^^ 2 + -25 * y ^^^ 2)" then ()
       
   839 else error "rational.sml norm_Rational 1 / (x ^^^ 2 + -25 * y ^^^ 2)";
       
   840 
       
   841 "nonterm.SK6 ----- SK060904-2a non-termination of add_fraction_p_";
       
   842 (*WN.2.6.03 from rlang.sml 56a 
       
   843 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)";
   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)";
   844 val NONE = rewrite_set_ thy false common_nominator_p t;
   884 val NONE = rewrite_set_ thy false add_fractions_p t;
   845 
   885 
   846 WN060831 nonterm.SK7 
   886 THE ERROR ALREADY OCCURS IN THIS PART:
   847 val t = str2term "(a + b * x) / (a + -1 * (b * x)) + (-1 * a + b * x) / (a + b * x)";
   887 val t = str2term "(a + b * x) / (a + -1 * (b * x)) + (-1 * a + b * x) / (a + b * x)";
   848 val NONE = add_fraction_p_ thy t; 
   888 val NONE = add_fraction_p_ thy t;
   849 *)
   889 
   850 
   890 SEE Test_Some.thy: section {* add_fractions_p downto exception Div raised ===
   851 
   891 *)
   852 (* ------------------------------------------------------------------- *)
   892 
   853 (*---------vvv------------ MG: ab 1.7.03 ----------------vvv-----------*)
   893 "-------- rational numerals --------------------------------------------------";
   854 (*                 Simplifier fuer beliebige Buchterme                 *) 
   894 "-------- rational numerals --------------------------------------------------";
   855 (* ------------------------------------------------------------------- *)
   895 "-------- rational numerals --------------------------------------------------";
   856 (*----------------------- norm_Rational_mg ----------------------------*)
       
   857 (* ------------------------------------------------------------------- *)
       
   858 
       
   859 "-------- numeral rationals -----------------------------";
       
   860 "-------- numeral rationals -----------------------------";
       
   861 "-------- numeral rationals -----------------------------";
       
   862 (*SRA Schalk I, p.40 Nr. 164b *)
   896 (*SRA Schalk I, p.40 Nr. 164b *)
   863 val t = str2term "(47/6 - 76/9 + 13/4)/(35/12)";
   897 val t = str2term "(47/6 - 76/9 + 13/4)/(35/12)";
   864 val SOME (t,_) = rewrite_set_ thy false norm_Rational(*_mg*) t;
   898 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
   865 term2str t;
   899 term2str t;
   866 if (term2str t) = "19 / 21" then ()
   900 if term2str t = "19 / 21" then ()
   867 else error "rational.sml: diff.behav. in norm_Rational_mg 1";
   901 else error "rational.sml: diff.behav. in norm_Rational_mg 1";
   868 
   902 
   869 (*SRA Schalk I, p.40 Nr. 166a *)
   903 (*SRA Schalk I, p.40 Nr. 166a *)
   870 val t = str2term "((5/4)/(4+22/7) + 37/20)*(110/3 - 110/9 * 23/11)";
   904 val t = str2term "((5/4)/(4+22/7) + 37/20)*(110/3 - 110/9 * 23/11)";
   871 val SOME (t,_) = rewrite_set_ thy false norm_Rational(*_mg*) t;
   905 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
   872 term2str t;
   906 term2str t;
   873 if (term2str t) = "45 / 2" then ()
   907 if term2str t = "45 / 2" then ()
   874 else error "rational.sml: diff.behav. in norm_Rational_mg 2";
   908 else error "rational.sml: diff.behav. in norm_Rational_mg 2";
   875 
   909 
   876 
   910 "-------- examples cancellation from: Mathematik 1 Schalk --------------------";
   877 "-------- cancellation ----------------------------------";
   911 "-------- examples cancellation from: Mathematik 1 Schalk --------------------";
   878 "-------- cancellation ----------------------------------";
   912 "-------- examples cancellation from: Mathematik 1 Schalk --------------------";
   879 "-------- cancellation ----------------------------------";
       
   880 (* e190c Stefan K.*)
   913 (* e190c Stefan K.*)
   881 val t = str2term
   914 val t = str2term "((1 + 9*a^^^2) * (1 + 3*a)) / ((3*a + 9*a^^^2) * (1 + 3*a))";
   882 "((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;
   883 val SOME (t,_) = rewrite_set_ thy false norm_Rational(*_mg*) 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;
   884 term2str t;
   928 term2str t;
   885 if (term2str t) = 
   929 if term2str t = "-1"
   886 "(1 + 9 * a ^^^ 2) / (3 * a + 9 * a ^^^ 2)"
   930 then () else error "rational.sml: diff.behav. in norm_Rational_mg 5";
   887 then ()
       
   888 else error "rational.sml: diff.behav. in norm_Rational_mg 3";
       
   889 
       
   890 (* e192b Stefan K.*)
       
   891 val t = str2term
       
   892 "((x ^^^ 2)*(7 * x + (-1) * y))/((y ^^^ 2)*(7 * x + (-1) * y))";
       
   893 val SOME (t,_) = rewrite_set_ thy false norm_Rational(*_mg*) t;
       
   894 term2str t;
       
   895 if (term2str t) = 
       
   896 "x ^^^ 2 / y ^^^ 2"
       
   897 then ()
       
   898 else error "rational.sml: diff.behav. in norm_Rational_mg 4";
       
   899 
       
   900 (*SRC Schalk I, p.66 Nr. 379c *)
       
   901 val t = str2term 
       
   902 "(a - b)/(b - a)";
       
   903 val SOME (t,_) = rewrite_set_ thy false norm_Rational(*_mg*) t;
       
   904 term2str t;
       
   905 if (term2str t) =
       
   906 "-1"
       
   907 then ()
       
   908 else error "rational.sml: diff.behav. in norm_Rational_mg 5";
       
   909 
   931 
   910 (*SRC Schalk I, p.66 Nr. 380b *)
   932 (*SRC Schalk I, p.66 Nr. 380b *)
   911 val t = str2term 
   933 val t = str2term "15*(3*x + 3) * (4*x + 9)  /  (12*(2*x + 7) * (5*x + 5))";
   912 "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;
   913 val SOME (t,_) = rewrite_set_ thy false norm_Rational(*_mg*) t;
   935 if term2str t = "(27 + 12 * x) / (28 + 8 * x)"
   914 term2str t;
   936 then () else error "rational.sml: diff.behav. in norm_Rational_mg 6";
   915 if (term2str t) =
   937 
   916 "(27 + 12 * x) / (28 + 8 * x)"
   938 (*Schalk I, p.60 Nr. 215c: was not cancelled with Isabelle2002 *)
   917 then ()
   939 val t = str2term "(a + b)^^^4 * (x - y)  /  ((x - y)^^^3 * (a + b)^^^2)";
   918 else error "rational.sml: diff.behav. in norm_Rational_mg 6";
   940 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
   919 
   941 if term2str t = "(a ^^^ 2 + 2 * a * b + b ^^^ 2) / (x ^^^ 2 + -2 * x * y + y ^^^ 2)"
   920 (*Schalk I, p.60 Nr. 215c *)
   942 then () else error "rational.sml: diff.behav. in norm_Rational_mg 7";
   921 (* Falsches Ergebnis: rechnet lange und cancel_p kann nicht weiter krzen!!!*)
       
   922 (* WN060831????MG1 
       
   923 val t = str2term "(a+b)^^^4*(x - y)/((x - y)^^^3*(a+b)^^^2)";
       
   924 val SOME (t,_) = rewrite_set_ thy false norm_Rational(*_mg*) t;
       
   925 term2str t;
       
   926 if (term2str t) =
       
   927 "(a ^^^ 4 * x + -1 * a ^^^ 4 * y + 4 * a ^^^ 3 * b * x + -4 * a ^^^ 3 * b * y + 6 * a ^^^ 2 * b ^^^ 2 * x + -6 * a ^^^ 2 * b ^^^ 2 * y + 4 * a * b ^^^ 3 * x + -4 * a * b ^^^ 3 * y + b ^^^ 4 * x + -1 * b ^^^ 4 * y) /(a ^^^ 2 * x ^^^ 3 + -3 * a ^^^ 2 * x ^^^ 2 * y + 3 * a ^^^ 2 * x * y ^^^ 2 + -1 * a ^^^ 2 * y ^^^ 3 + 2 * a * b * x ^^^ 3 + -6 * a * b * x ^^^ 2 * y + 6 * a * b * x * y ^^^ 2 + -2 * a * b * y ^^^ 3 + b ^^^ 2 * x ^^^ 3 + -3 * b ^^^ 2 * x ^^^ 2 * y + 3 * b ^^^ 2 * x * y ^^^ 2 + -1 * b ^^^ 2 * y ^^^ 3)"
       
   928 then ()
       
   929 else error "rational.sml: diff.behav. in norm_Rational_mg 7";
       
   930 *)
       
   931 (*val t = str2term 
       
   932 "(a ^^^ 4 * x + -1 * a ^^^ 4 * y + 4 * a ^^^ 3 * b * x + -4 * a ^^^ 3 * b * y + 6 * a ^^^ 2 * b ^^^ 2 * x + -6 * a ^^^ 2 * b ^^^ 2 * y + 4 * a * b ^^^ 3 * x + -4 * a * b ^^^ 3 * y + b ^^^ 4 * x + -1 * b ^^^ 4 * y) /(a ^^^ 2 * x ^^^ 3 + -3 * a ^^^ 2 * x ^^^ 2 * y + 3 * a ^^^ 2 * x * y ^^^ 2 + -1 * a ^^^ 2 * y ^^^ 3 + 2 * a * b * x ^^^ 3 + -6 * a * b * x ^^^ 2 * y + 6 * a * b * x * y ^^^ 2 + -2 * a * b * y ^^^ 3 + b ^^^ 2 * x ^^^ 3 + -3 * b ^^^ 2 * x ^^^ 2 * y + 3 * b ^^^ 2 * x * y ^^^ 2 + -1 * b ^^^ 2 * y ^^^ 3)"
       
   933 val SOME (t,_) = rewrite_set_ thy false cancel_p t;
       
   934 term2str t;*)
       
   935 (* uncaught exception nonexhaustive binding failure
       
   936    raised at: stdIn:93.1-93.51 *)
       
   937 
       
   938 (*Schalk I, p.66 Nr. 381a *)
       
   939 (* ACHTUNG: rechnet ca. 2 Minuten !!! *)
       
   940 (* WN060831???MG2
       
   941 val t = str2term "18*(a+b)^^^3*(a - b)^^^2/(72*(a - b)^^^3*(a+b)^^^2)";
       
   942 val SOME (t,_) = rewrite_set_ thy false norm_Rational(*_mg*) t;
       
   943 term2str t;
       
   944 if (term2str t) =
       
   945 "(a + b) / (4 * a + -4 * b)"
       
   946 then () else error "rational.sml: diff.behav. in norm_Rational_mg 8";
       
   947 *)
       
   948 
   943 
   949 (*SRC Schalk I, p.66 Nr. 381b *)
   944 (*SRC Schalk I, p.66 Nr. 381b *)
   950 val t = str2term 
   945 val t = str2term 
   951 "(4*x^^^2 - 20*x + 25)/(2*x - 5)^^^3";
   946 "(4*x^^^2 - 20*x + 25)/(2*x - 5)^^^3";
   952 val SOME (t,_) = rewrite_set_ thy false norm_Rational(*_mg*) t;
   947 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
   953 term2str t;
   948 if term2str t = "1 / (-5 + 2 * x)"
   954 if (term2str t) =
   949 then () else error "rational.sml: diff.behav. in norm_Rational_mg 9";
   955 "-1 / (5 + -2 * x)"
   950 
   956 then ()
   951 (* e190c Stefan K.*)
   957 else error "rational.sml: diff.behav. in norm_Rational_mg 9";
   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";
   958 
  1005 
   959 (*SRC Schalk I, p.66 Nr. 381c *)
  1006 (*SRC Schalk I, p.66 Nr. 381c *)
   960 val t = str2term 
  1007 val t = str2term "(27*a^^^3 + 9*a^^^2+3*a+1) / (27*a^^^3 + 18*a^^^2+3*a)";
   961 "(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;
   962 val SOME (t,_) = rewrite_set_ thy false norm_Rational(*_mg*) t;
  1009 if term2str t = "(1 + 9 * a ^^^ 2) / (3 * a + 9 * a ^^^ 2)"
   963 term2str t;
  1010 then () else error "rational.sml: diff.behav. in norm_Rational_mg 10";
   964 if (term2str t) =
       
   965 "(1 + 9 * a ^^^ 2) / (3 * a + 9 * a ^^^ 2)"
       
   966 then ()
       
   967 else error "rational.sml: diff.behav. in norm_Rational_mg 10";
       
   968 
  1011 
   969 (*SRC Schalk I, p.66 Nr. 383a *)
  1012 (*SRC Schalk I, p.66 Nr. 383a *)
   970 val t = str2term 
  1013 val t = str2term "(5*a^^^2 - 5*a*b) / (a - b)^^^2";
   971 "(5*a^^^2 - 5*a*b)/(a - b)^^^2";
  1014 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
   972 val SOME (t,_) = rewrite_set_ thy false norm_Rational(*_mg*) t;
  1015 if term2str t = "-5 * a / (-1 * a + b)"
   973 term2str t;
  1016 then () else error "rational.sml: diff.behav. in norm_Rational_mg 11";
   974 if (term2str t) =
  1017 
   975 "5 * a / (a + -1 * b)"
  1018 "----- NOT TERMINATING ?: worked before 0707xx";
   976 then ()
  1019 val t = str2term "(a^^^2 - 1)*(b + 1) / ((b^^^2 - 1)*(a+1))";
   977 else error "rational.sml: diff.behav. in norm_Rational_mg 11";
  1020 (* WN130911 "exception Div raised" by 
   978 
  1021   cancel_p_ thy (str2term ("(-1 + -1 * b + a ^^^ 2 + a ^^^ 2 * b) /" ^
   979 
  1022                            "(-1 + -1 * a + b ^^^ 2 + a * b ^^^ 2)"))
   980 "-------- common denominator ----------------------------";
  1023 
   981 "-------- common denominator ----------------------------";
  1024 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
   982 "-------- common denominator ----------------------------";
  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 --------------";
   983 (*SRA Schalk I, p.67 Nr. 403a *)
  1032 (*SRA Schalk I, p.67 Nr. 403a *)
   984 val t = str2term 
  1033 val t = str2term "4/x - 3/y - 1";
   985 "4/x - 3/y - 1";
  1034 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
   986 val SOME (t,_) = rewrite_set_ thy false norm_Rational(*_mg*) t;
  1035 if term2str t = "(-3 * x + 4 * y + -1 * x * y) / (x * y)"
   987 term2str t;
  1036 then () else error "rational.sml: diff.behav. in norm_Rational_mg 12";
   988 if (term2str t) =
  1037 
   989 "(-3 * x + 4 * y + -1 * x * y) / (x * y)"
  1038 val t = str2term "(2*a+3*b)/(b*c) + (3*c+a)/(a*c) - (2*a^^^2+3*b*c)/(a*b*c)";
   990 then ()
  1039 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
   991 else error "rational.sml: diff.behav. in norm_Rational_mg 12";
  1040 if term2str t = "4 / c"
   992 
  1041 then () else error "rational.sml: diff.behav. in norm_Rational_mg 13";
   993 (*SRA Schalk I, p.67 Nr. 407b *)
       
   994 val t = str2term 
       
   995 "(2*a+3*b)/(b*c) + (3*c+a)/(a*c) - (2*a^^^2+3*b*c)/(a*b*c)";
       
   996 val SOME (t,_) = rewrite_set_ thy false norm_Rational(*_mg*) t;
       
   997 term2str t;
       
   998 if (term2str t) =
       
   999 "4 / c"
       
  1000 then ()
       
  1001 else error "rational.sml: diff.behav. in norm_Rational_mg 13";
       
  1002 
  1042 
  1003 (*SRA Schalk I, p.67 Nr. 410b *)
  1043 (*SRA Schalk I, p.67 Nr. 410b *)
  1004 val t = str2term 
  1044 val t = str2term "1/(x+1) + 1/(x+2) - 2/(x+3)";
  1005 "1/(x+1) + 1/(x+2) - 2/(x+3)";
  1045 (* WN130911 non-termination due to non-termination of
  1006 val SOME (t,_) = rewrite_set_ thy false norm_Rational(*_mg*) t;
  1046   cancel_p_ thy (str2term "(5 + 3 * x) / (6 + 11 * x + 6 * x ^^^ 2 + x ^^^ 3)")
  1007 term2str t;
  1047 
  1008 if (term2str t) =
  1048 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1009 "(5 + 3 * x) / (6 + 11 * x + 6 * x ^^^ 2 + x ^^^ 3)"
  1049 if term2str t = "(5 + 3 * x) / (6 + 11 * x + 6 * x ^^^ 2 + x ^^^ 3)"
  1010 then ()
  1050 then () else error "rational.sml: diff.behav. in norm_Rational_mg 14";
  1011 else error "rational.sml: diff.behav. in norm_Rational_mg 14";
  1051 *)
  1012 
  1052 
  1013 (*SRA Schalk I, p.67 Nr. 413b *)
  1053 (*SRA Schalk I, p.67 Nr. 413b *)
  1014 val t = str2term 
  1054 val t = str2term "(1 + x)/(1 - x)  -  (1 - x)/(1 + x)  +  2*x/(1 - x^^^2)";
  1015 "(1+x)/(1 - x) - (1 - x)/(1+x) + 2*x/(1 - x^^^2)";
  1055 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1016 val SOME (t,_) = rewrite_set_ thy false norm_Rational(*_mg*) t;
  1056 if term2str t = "6 * x / (1 + -1 * x ^^^ 2)"
  1017 term2str t;
  1057 then () else error "rational.sml: diff.behav. in norm_Rational_mg 15";
  1018 if (term2str t) =
       
  1019 "6 * x / (1 + -1 * x ^^^ 2)"
       
  1020 then ()
       
  1021 else error "rational.sml: diff.behav. in norm_Rational_mg 15";
       
  1022 
  1058 
  1023 (*SRA Schalk I, p.68 Nr. 414a *)
  1059 (*SRA Schalk I, p.68 Nr. 414a *)
  1024 val t = str2term 
  1060 val t = str2term "(x + 2)/(x - 1)  +  (x - 3)/(x - 2)  -  (x + 1)/((x - 1)*(x - 2))";
  1025 "(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;
  1026 val SOME (t,_) = rewrite_set_ thy false norm_Rational(*_mg*) t;
  1062 if term2str t ="(-2 + -5 * x + 2 * x ^^^ 2) / (2 + -3 * x + x ^^^ 2)"
  1027 term2str t;
  1063 then () else error "rational.sml: diff.behav. in norm_Rational_mg 16";
  1028 if (term2str t) =
       
  1029 "(-2 + -5 * x + 2 * x ^^^ 2) / (2 + -3 * x + x ^^^ 2)"
       
  1030 then ()
       
  1031 else error "rational.sml: diff.behav. in norm_Rational_mg 16";
       
  1032 
       
  1033 (*SRA Schalk I, p.68 Nr. 423a *)
       
  1034 val t = str2term 
       
  1035 "(2*x+3*y)/x + (4*x^^^3 - x*y^^^2 - 3*y^^^3)/(x^^^3 - 2*x^^^2*y+x*y^^^2) - (5*x+6*y)/(x - y)";
       
  1036 val SOME (t,_) = rewrite_set_ thy false norm_Rational(*_mg*) t;
       
  1037 term2str t;
       
  1038 if (term2str t) =
       
  1039 "1"
       
  1040 then ()
       
  1041 else error "rational.sml: diff.behav. in norm_Rational_mg 17";
       
  1042 
  1064 
  1043 (*SRA Schalk I, p.68 Nr. 428b *)
  1065 (*SRA Schalk I, p.68 Nr. 428b *)
  1044 val t = str2term 
  1066 val t = str2term 
  1045 "1/(a - b)^^^2 + 1/(a+b)^^^2 - 2/(a^^^2 - b^^^2) - 4*(b^^^2 - 1)/(a^^^2 - b^^^2)^^^2";
  1067   "1/(a - b)^^^2  +  1/(a + b)^^^2  -  2/(a^^^2 - b^^^2)  -  4*(b^^^2 - 1)/(a^^^2 - b^^^2)^^^2";
  1046 val SOME (t,_) = rewrite_set_ thy false norm_Rational(*_mg*) t;
  1068 (* WN130911 non-termination due to non-termination of
  1047 term2str t;
  1069   cancel_p_ thy (str2term "(4 + -4 * b ^^^ 2) / (a ^^^ 4 + -2 * (a ^^^ 2 * b ^^^ 2) + b ^^^ 4)")
  1048 if (term2str t) =
  1070 
  1049 "4 / (a ^^^ 4 + -2 * a ^^^ 2 * b ^^^ 2 + b ^^^ 4)"
  1071 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1050 then ()
  1072 if term2str t = "4 / (a ^^^ 4 + -2 * a ^^^ 2 * b ^^^ 2 + b ^^^ 4)"
  1051 else error "rational.sml: diff.behav. in norm_Rational_mg 18";
  1073 then () else error "rational.sml: diff.behav. in norm_Rational_mg 18";
       
  1074 *)
  1052 
  1075 
  1053 (*SRA Schalk I, p.68 Nr. 430b *)
  1076 (*SRA Schalk I, p.68 Nr. 430b *)
  1054 val t = str2term 
  1077 val t = str2term 
  1055 "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";
  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";
  1056 val SOME (t,_) = rewrite_set_ thy false norm_Rational(*_mg*) t;
  1079 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1057 term2str t;
  1080 if term2str t = "a + 3 * b"
  1058 if (term2str t) =
  1081 then () else error "rational.sml: diff.behav. in norm_Rational_mg 19";
  1059 "a + 3 * b"
       
  1060 then ()
       
  1061 else error "rational.sml: diff.behav. in norm_Rational_mg 19";
       
  1062 
       
  1063 
  1082 
  1064 (*SRA Schalk I, p.68 Nr. 432 *)
  1083 (*SRA Schalk I, p.68 Nr. 432 *)
  1065 val t = str2term 
  1084 val t = str2term 
  1066 "(a^^^2+a*b)/(a^^^2 - b^^^2) - (b^^^2 - a*b)/(b^^^2 - a^^^2) + a^^^2*(a - b)/(a^^^3 - a^^^2*b) - 2*a*(a^^^2 - b^^^2)/(a^^^3 - a*b^^^2) - 2*b^^^2/(a^^^2 - b^^^2)";
  1085   ("(a^^^2 + a*b) / (a^^^2 - b^^^2)  -  (b^^^2 - a*b) / (b^^^2 - a^^^2)  +  " ^
  1067 val SOME (t,_) = rewrite_set_ thy false norm_Rational(*_mg*) t;
  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;
  1068 term2str t;
  1089 term2str t;
  1069 if (term2str t) =
  1090 if term2str t = "0"
  1070 "0"
  1091 then () else error "rational.sml: diff.behav. in norm_Rational_mg 20";
  1071 then ()
  1092 
  1072 else error "rational.sml: diff.behav. in norm_Rational_mg 20";
  1093 (* some example *)
  1073 
  1094 val t = str2term "3*a / (a*b)  +  x/y";
  1074 (*Eigenes*)
  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
  1075 val t = str2term 
  1124 val t = str2term 
  1076 "3*a/(a*b) + x/y";
  1125   ("(9 * a ^^^ 2 + -16 * b ^^^ 2) / (4 * c + 3 * e) /" ^
  1077 val SOME (t,_) = rewrite_set_ thy false norm_Rational(*_mg*) t;
  1126   "(9 * a ^^^ 2 + -16 * b ^^^ 2)");
  1078 term2str t;
  1127 NONE = cancel_p_ thy t;
  1079 if (term2str t) =
  1128 
  1080 "(3 * y + b * x) / (b * y)"
  1129 if term2str t = "1 / (4 * c + 3 * e)" then ()
  1081 then ()
       
  1082 else error "rational.sml: diff.behav. in norm_Rational_mg 21";
       
  1083 
       
  1084 
       
  1085 "-------- multiply and cancel ---------------------------";
       
  1086 "-------- multiply and cancel ---------------------------";
       
  1087 "-------- multiply and cancel ---------------------------";
       
  1088 (*SRM Schalk I, p.68 Nr. 436a *)
       
  1089 val t = str2term 
       
  1090 "3*(x+y)/(15*(x - y)) * 25*(x - y)^^^2/(18*(x+y)^^^2)";
       
  1091 val SOME (t,_) = rewrite_set_ thy false norm_Rational(*_mg*) t;
       
  1092 term2str t;
       
  1093 if (term2str t) =
       
  1094 "(5 * x + -5 * y) / (18 * x + 18 * y)"
       
  1095 then ()
       
  1096 else error "rational.sml: diff.behav. in norm_Rational_mg 22";
       
  1097 
       
  1098 (*SRM.test Schalk I, p.68 Nr. 436b *)
       
  1099 (*WN060420???MG3 crashes with method 'simplify' in 
       
  1100   IsacCore > Simplification > Rational Terms > Multiplication > No.2*)
       
  1101 val t = str2term "5*a*(a - b)^^^2*(a + b)^^^3/(7*b*(a - b)^^^3) * 7*b/(a + b)^^^3";
       
  1102 val SOME (t,_) = rewrite_set_ thy false norm_Rational(*_mg*) t;
       
  1103 term2str t;
       
  1104 if (term2str t) =
       
  1105 "5 * a / (a + -1 * b)"
       
  1106 then ()
       
  1107 else error "rational.sml: diff.behav. in norm_Rational_mg 23";
       
  1108 
       
  1109 (*Schalk I, p.68 Nr. 437a *)
       
  1110 val t = str2term "(3*a - 4*b)/(4*c+3*e) * (3*a+4*b)/(9*a^^^2 - 16*b^^^2)";
       
  1111 val SOME (t,_) = rewrite_set_ thy false norm_Rational(*_mg*) t;
       
  1112 if (term2str t) = "1 / (4 * c + 3 * e)" then ()
       
  1113 else error "rational.sml: diff.behav. in norm_Rational_mg 24";
  1130 else error "rational.sml: diff.behav. in norm_Rational_mg 24";
       
  1131 *)
  1114 
  1132 
  1115 "----- S.K. corrected non-termination 060904";
  1133 "----- S.K. corrected non-termination 060904";
  1116 val t = str2term "(3*a - 4*b) * (3*a+4*b)/((4*c+3*e)*(9*a^^^2 - 16*b^^^2))";
  1134 val t = str2term "(3*a - 4*b) * (3*a+4*b)/((4*c+3*e)*(9*a^^^2 - 16*b^^^2))";
  1117 val SOME (t',_) = rewrite_set_ thy false make_polynomial t;
  1135 val SOME (t, _) = rewrite_set_ thy false make_polynomial t;
  1118 term2str t';
  1136 if term2str t = 
  1119 if term2str t' = 
       
  1120   "(9 * a ^^^ 2 + -16 * b ^^^ 2) /\n(36 * a ^^^ 2 * c + 27 * a ^^^ 2 * e + -64 * b ^^^ 2 * c +\n -48 * b ^^^ 2 * e)"
  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)"
  1121 (*"(9 * a ^^^ 2 + -16 * b ^^^ 2) / (36 * a ^^^ 2 * c + 27 * a ^^^ 2 * e + -64 * b ^^^ 2 * c + -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)"*)
  1122 then () else error "rational.sml: S.K.8..corrected 060904-6";
  1139 then () else error "rational.sml: S.K.8..corrected 060904-6";
  1123 
  1140 
  1124 "----- S.K. corrected non-termination of cancel_p_";
  1141 "----- S.K. corrected non-termination of cancel_p_";
  1125 val t'' = str2term ("(9 * a ^^^ 2 + -16 * b ^^^ 2) /" ^
  1142 val t'' = str2term ("(9 * a ^^^ 2 + -16 * b ^^^ 2) /" ^
  1126 "(36 * a^^^2 * c + (27 * a^^^2 * e + (-64 * b^^^2 * c + -48 * b^^^2 * e)))");
  1143   "(36 * a^^^2 * c + (27 * a^^^2 * e + (-64 * b^^^2 * c + -48 * b^^^2 * e)))");
  1127 val SOME (t',_) = rewrite_set_ thy false cancel_p t'';
  1144 val SOME (t',_) = rewrite_set_ thy false cancel_p t'';
  1128 if term2str t' = "1 / (4 * c + 3 * e)" then ()
  1145 if term2str t' = "1 / (4 * c + 3 * e)"
  1129 else error "rational.sml: diff.behav. in cancel_p S.K.8";
  1146 then () else error "rational.sml: diff.behav. in cancel_p S.K.8";
  1130 
  1147 
  1131 (*Schalk I, p.68 Nr. 437b *)
  1148 (*------- Schalk I, p.68 Nr. 437b*)
  1132 (* nonterm.SK9 loops: cancel_p kann nicht weiter kuerzen!!! *)
  1149 val t = str2term "(a + b)/(x^^^2 - y^^^2) * ((x - y)^^^2/(a^^^2 - b^^^2))";
  1133 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;
  1134 (* val SOME (t,_) = rewrite_set_ thy false norm_Rational(*_mg*) t'';
  1151 :
  1135    *)
  1152 ####  rls: cancel_p on: (a * x ^^^ 2 + -2 * (a * (x * y)) + a * y ^^^ 2 + b * x ^^^ 2 +
  1136 
  1153  -2 * (b * (x * y)) +
  1137 "================delete===";
  1154  b * y ^^^ 2) /
  1138 (*a casual output from above*)
  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 
  1139 val t = str2term 
  1190 val t = str2term 
  1140 "(a * x ^^^ 2 + -2 * a * x * y + a * y ^^^ 2 + b * x ^^^ 2 + -2 * b * x * y + b * y ^^^ 2) /(a ^^^ 2 * x ^^^ 2 + -1 * a ^^^ 2 * y ^^^ 2 + -1 * b ^^^ 2 * x ^^^ 2 + b ^^^ 2 * y ^^^ 2)"; 
  1191   ("(-9 * (a^^^3 * b) + -9 * (a^^^2 * b^^^2) + a^^^5 * b + a^^^4 * b^^^2)  /" ^
  1141 (* WN060831 nonterm.SK10 
  1192   "(a^^^3 * b + -1 * (a * b^^^3))  /  (3 + (a::real))");
  1142 val SOME (t,_) = rewrite_set_ thy false cancel_p t;
  1193 AS
  1143 term2str t;
  1194 NONE = cancel_p_ thy t;
  1144 *)
  1195 
  1145 
       
  1146 (*SRM Schalk I, p.68 Nr. 438a *)
       
  1147 val t = str2term 
       
  1148 "x*y/(x*y - y^^^2)*(x^^^2 - x*y)";
       
  1149 val SOME (t,_) = rewrite_set_ thy false norm_Rational(*_mg*) t;
       
  1150 term2str t;
       
  1151 if (term2str t) =
       
  1152 "x ^^^ 2"
       
  1153 then ()
       
  1154 else error "rational.sml: diff.behav. in norm_Rational_mg 24";
       
  1155 
       
  1156 (*SRM Schalk I, p.68 Nr. 439b *)
       
  1157 val t = str2term 
       
  1158 "(4*x^^^2+4*x+1)*((x^^^2 - 2*x^^^3)/(4*x^^^2+2*x))";
       
  1159 val SOME (t,_) = rewrite_set_ thy false norm_Rational(*_mg*) t;
       
  1160 term2str t;
       
  1161 if (term2str t) =
       
  1162 "(x + -4 * x ^^^ 3) / 2"
       
  1163 then ()
       
  1164 else error "rational.sml: diff.behav. in norm_Rational_mg 25";
       
  1165 
       
  1166 (*SRM Schalk I, p.68 Nr. 440a *)
       
  1167 val t = str2term 
       
  1168 "(x^^^2 - 2*x)/(x^^^2 - 3*x) * (x - 3)^^^2/(x^^^2 - 4)";
       
  1169 val SOME (t,_) = rewrite_set_ thy false norm_Rational(*_mg*) t;
       
  1170 term2str t;
       
  1171 if (term2str t) =
       
  1172 "(-3 + x) / (2 + x)"
       
  1173 then ()
       
  1174 else error "rational.sml: diff.behav. in norm_Rational_mg 26";
       
  1175 
       
  1176 "----- Schalk I, p.68 Nr. 440b SK11 works since 0707xx";
       
  1177 val t = str2term 
       
  1178 "(a^^^3 - 9*a)/(a^^^3*b - a*b^^^3)*(a^^^2*b+a*b^^^2)/(a+3)";
       
  1179 val SOME (t,_) = rewrite_set_ thy false norm_Rational t;
       
  1180 if term2str t = "(-3 * a + a ^^^ 2) / (a + -1 * b)" then ()
  1196 if term2str t = "(-3 * a + a ^^^ 2) / (a + -1 * b)" then ()
  1181 else error "rational.sml: diff.behav. in norm_Rational 27";
  1197 else error "rational.sml: diff.behav. in norm_Rational 27";
       
  1198 *)
  1182 
  1199 
  1183 "----- SK12 works since 0707xx";
  1200 "----- SK12 works since 0707xx";
  1184 val t = str2term "(a^^^3 - 9*a)*(a^^^2*b+a*b^^^2)/((a^^^3*b - a*b^^^3)*(a+3))";
  1201 val t = str2term "(a^^^3 - 9*a) * (a^^^2*b+a*b^^^2)  /  ((a^^^3*b - a*b^^^3) * (a+3))";
  1185 val SOME (t',_) = rewrite_set_ thy false norm_Rational t; term2str t';
  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;
  1186 if term2str t' = "(-3 * a + a ^^^ 2) / (a + -1 * b)" then ()
  1206 if term2str t' = "(-3 * a + a ^^^ 2) / (a + -1 * b)" then ()
  1187 else error "rational.sml: diff.behav. in norm_Rational 28";
  1207 else error "rational.sml: diff.behav. in norm_Rational 28";
  1188 
  1208 *)
  1189 
  1209 
  1190 "-------- common denominator and multiplication ---------";
  1210 "-------- examples common denominator and multiplication from: Schalk --------";
  1191 "-------- common denominator and multiplication ---------";
  1211 "-------- examples common denominator and multiplication from: Schalk --------";
  1192 "-------- common denominator and multiplication ---------";
  1212 "-------- examples common denominator and multiplication from: Schalk --------";
  1193 (*SRAM Schalk I, p.69 Nr. 441b *)
  1213 (*------- SRAM Schalk I, p.69 Nr. 441b *)
  1194 val t = str2term "(4*a/3 + 3*b^^^2/a^^^3 + b/(4*a))*(4*b/(3*a))";
  1214 val t = str2term "(4*a/3 + 3*b^^^2/a^^^3 + b/(4*a))*(4*b/(3*a))";
  1195 val SOME (t,_) = rewrite_set_ thy false norm_Rational(*_mg*) t;
  1215 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1196 term2str t;
  1216 if term2str t = "(36 * b ^^^ 3 + 3 * a ^^^ 2 * b ^^^ 2 + 16 * a ^^^ 4 * b) / (9 * a ^^^ 4)"
  1197 if (term2str t) =
       
  1198   "(36 * b ^^^ 3 + 3 * a ^^^ 2 * b ^^^ 2 + 16 * a ^^^ 4 * b) / (9 * a ^^^ 4)"
       
  1199 then () else error "rational.sml: diff.behav. in norm_Rational_mg 28";
  1217 then () else error "rational.sml: diff.behav. in norm_Rational_mg 28";
  1200 
  1218 
  1201 (*SRAM Schalk I, p.69 Nr. 442b *)
  1219 (*------- SRAM Schalk I, p.69 Nr. 442b *)
  1202 val t = str2term "(15*a^^^2/x^^^3 - 5*b^^^4/x^^^2 + 25*c^^^2/x)*(x^^^3/(5*a*b^^^3*c^^^3)) + 1/c^^^3 * (b*x/a - 3*a/b^^^3)";
  1220 val t = str2term ("(15*a^^^2/x^^^3 - 5*b^^^4/x^^^2 + 25*c^^^2/x) * " ^
  1203 val SOME (t,_) = rewrite_set_ thy false norm_Rational(*_mg*) t;
  1221   "(x^^^3/(5*a*b^^^3*c^^^3)) + 1/c^^^3 * (b*x/a - 3*a/b^^^3)");
  1204 term2str t;
  1222 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1205 if (term2str t) =
  1223 if term2str t = "5 * x ^^^ 2 / (a * b ^^^ 3 * c)"
  1206 "5 * x ^^^ 2 / (a * b ^^^ 3 * c)"
       
  1207 then () else error "rational.sml: diff.behav. in norm_Rational_mg 29";
  1224 then () else error "rational.sml: diff.behav. in norm_Rational_mg 29";
  1208 
  1225 
  1209 (*SRAM Schalk I, p.69 Nr. 443b *)
  1226 (*------- SRAM Schalk I, p.69 Nr. 443b *)
  1210 val t = str2term "(a/2 + b/3)*(b/3 - a/2)";
  1227 val t = str2term "(a/2 + b/3) * (b/3 - a/2)";
  1211 val SOME (t,_) = rewrite_set_ thy false norm_Rational(*_mg*) t;
  1228 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1212 term2str t;
  1229 if term2str t = "(-9 * a ^^^ 2 + 4 * b ^^^ 2) / 36"
  1213 if (term2str t) =
       
  1214 "(-9 * a ^^^ 2 + 4 * b ^^^ 2) / 36"
       
  1215 then () else error "rational.sml: diff.behav. in norm_Rational_mg 30";
  1230 then () else error "rational.sml: diff.behav. in norm_Rational_mg 30";
  1216 
  1231 
  1217 (*SRAM Schalk I, p.69 Nr. 445b *)
  1232 (*------- SRAM Schalk I, p.69 Nr. 445b *)
  1218 val t = str2term "(a^^^2/9 + 2*a/(3*b) + 4/b^^^2)*(a/3 - 2/b) + 8/b^^^3";
  1233 val t = str2term "(a^^^2/9 + 2*a/(3*b) + 4/b^^^2)*(a/3 - 2/b) + 8/b^^^3";
  1219 val SOME (t,_) = rewrite_set_ thy false norm_Rational(*_mg*) t;
  1234 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1220 term2str t;
  1235 if term2str t = "a ^^^ 3 / 27"
  1221 if (term2str t) =
       
  1222 "a ^^^ 3 / 27"
       
  1223 then () else error "rational.sml: diff.behav. in norm_Rational_mg 31";
  1236 then () else error "rational.sml: diff.behav. in norm_Rational_mg 31";
  1224 
  1237 
  1225 (*SRAM Schalk I, p.69 Nr. 446b *)
  1238 (*------- SRAM Schalk I, p.69 Nr. 446b *)
  1226 val t = str2term "(x/(5*x + 4*y) - y/(5*x - 4*y) + 1)*(25*x^^^2 - 16*y^^^2)";
  1239 val t = str2term "(x/(5*x + 4*y) - y/(5*x - 4*y) + 1)*(25*x^^^2 - 16*y^^^2)";
  1227 val SOME (t,_) = rewrite_set_ thy false norm_Rational(*_mg*) t;
  1240 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1228 term2str t;
  1241 if term2str t = "30 * x ^^^ 2 + -9 * x * y + -20 * y ^^^ 2"
  1229 if (term2str t) =
  1242 then () else error "rational.sml: diff.behav. in norm_Rational_mg 32";
  1230 "30 * x ^^^ 2 + -9 * x * y + -20 * y ^^^ 2"
  1243 
  1231 then ()
  1244 (*------- SRAM Schalk I, p.69 Nr. 449a *)(*Achtung: rechnet ca 8 Sekunden*)
  1232 else error "rational.sml: diff.behav. in norm_Rational_mg 32";
       
  1233 
       
  1234 (*SRAM Schalk I, p.69 Nr. 449a *)(*Achtung: rechnet ca 8 Sekunden*)
       
  1235 val t = str2term 
  1245 val t = str2term 
  1236 "(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)";
  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)";
  1237 val SOME (t,_) = rewrite_set_ thy false norm_Rational(*_mg*) t;
  1247 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1238 term2str t;
  1248 if term2str t = "(-81 * x ^^^ 4 + 16 * x ^^^ 8 * y ^^^ 4) / (81 * y ^^^ 8)"
  1239 if (term2str t) = "(-81 * x ^^^ 4 + 16 * x ^^^ 8 * y ^^^ 4) / (81 * y ^^^ 8)"
       
  1240 then () else error "rational.sml: diff.behav. in norm_Rational_mg 33";
  1249 then () else error "rational.sml: diff.behav. in norm_Rational_mg 33";
  1241 
  1250 
  1242 
  1251 (*------- SRAM Schalk I, p.69 Nr. 450a *)
  1243 (*SRAM Schalk I, p.69 Nr. 450a *)
       
  1244 val t = str2term 
  1252 val t = str2term 
  1245 "(4*x/(3*y)+2*y/(3*x))^^^2 - (2*y/(3*x) - 2*x/y)*(2*y/(3*x)+2*x/y)";
  1253 "(4*x/(3*y)+2*y/(3*x))^^^2 - (2*y/(3*x) - 2*x/y)*(2*y/(3*x)+2*x/y)";
  1246 val SOME (t,_) = rewrite_set_ thy false norm_Rational(*_mg*) t;
  1254 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1247 term2str t;
  1255 if term2str t = "(52 * x ^^^ 2 + 16 * y ^^^ 2) / (9 * y ^^^ 2)"
  1248 if (term2str t) =
  1256 then () else error "rational.sml: diff.behav. in norm_Rational_mg 34";
  1249 "(52 * x ^^^ 2 + 16 * y ^^^ 2) / (9 * y ^^^ 2)"
  1257 
  1250 then ()
  1258 (*------- SRAM Schalk I, p.69 Nr. 442b --- abgewandelt*)
  1251 else error "rational.sml: diff.behav. in norm_Rational_mg 34";
       
  1252 
       
  1253 
       
  1254 "-------- double fractions ------------------------------";
       
  1255 "-------- double fractions ------------------------------";
       
  1256 "-------- double fractions ------------------------------";
       
  1257 (*SRD Schalk I, p.69 Nr. 454b *)
       
  1258 val t = str2term 
  1259 val t = str2term 
  1259 "((2 - x)/(2*a)) / (2*a/(x - 2))";
  1260   ("(15*a^^^4/(a*x^^^3)  -  5*a*((b^^^4 - 5*c^^^2*x) / x^^^2))  *  " ^
  1260 val SOME (t,_) = rewrite_set_ thy false norm_Rational(*_mg*) t;
  1261   "(x^^^3/(5*a*b^^^3*c^^^3))   +   a/c^^^3 * (x*(b/a) - 3*b*(a/b^^^4))");
  1261 term2str t;
  1262 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1262 if (term2str t) = 
  1263 if term2str t = "5 * x ^^^ 2 / (b ^^^ 3 * c)"
  1263 "(-4 + 4 * x + -1 * x ^^^ 2) / (4 * a ^^^ 2)"
  1264 then () else error "rational.sml: diff.behav. in norm_Rational_mg 53";
  1264 then ()
  1265 
  1265 else error "rational.sml: diff.behav. in norm_Rational_mg 35";
  1266 
  1266 
  1267 "-------- examples double fractions from: Mathematik 1 Schalk ----------------";
  1267 (*SRD Schalk I, p.69 Nr. 455a *)
  1268 "-------- examples double fractions from: Mathematik 1 Schalk ----------------";
  1268 val t = str2term 
  1269 "-------- examples double fractions from: Mathematik 1 Schalk ----------------";
  1269 "(a^^^2 + 1)/(a^^^2 - 1) / ((a+1)/(a - 1))";
  1270 "----- SRD Schalk I, p.69 Nr. 454b";
  1270 val SOME (t,_) = rewrite_set_ thy false norm_Rational(*_mg*) t;
  1271 val t = str2term "((2 - x)/(2*a)) / (2*a/(x - 2))";
  1271 term2str t;
  1272 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1272 if (term2str t) = 
  1273 if term2str t = "(-4 + 4 * x + -1 * x ^^^ 2) / (4 * a ^^^ 2)"
  1273 "(1 + a ^^^ 2) / (1 + 2 * a + a ^^^ 2)" then ()
  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 ()
  1274 else error "rational.sml: diff.behav. in norm_Rational_mg 36";
  1280 else error "rational.sml: diff.behav. in norm_Rational_mg 36";
  1275 
       
  1276 
  1281 
  1277 "----- Schalk I, p.69 Nr. 455b";
  1282 "----- Schalk I, p.69 Nr. 455b";
  1278 val t = str2term "(x^^^2 - 4)/(y^^^2 - 9)/((2+x)/(3 - y))";
  1283 val t = str2term "(x^^^2 - 4)/(y^^^2 - 9)/((2+x)/(3 - y))";
  1279 val SOME (t,_) = rewrite_set_ thy false norm_Rational(*_mg*) t;
  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;
  1280 if term2str t = "(2 + -1 * x) / (3 + y)" then ()
  1289 if term2str t = "(2 + -1 * x) / (3 + y)" then ()
  1281 else error "rational.sml: diff.behav. in norm_Rational_mg 37";
  1290 else error "rational.sml: diff.behav. in norm_Rational_mg 37";
       
  1291 *)
  1282 
  1292 
  1283 "----- SK060904-1a non-termination of cancel_p_ ?: worked before 0707xx";
  1293 "----- SK060904-1a non-termination of cancel_p_ ?: worked before 0707xx";
  1284 val t = str2term "(x^^^2 - 4)*(3 - y)/((y^^^2 - 9)*(2+x))";
  1294 val t = str2term "(x^^^2 - 4)*(3 - y) / ((y^^^2 - 9)*(2+x))";
  1285 val SOME (t,_) = rewrite_set_ thy false norm_Rational t;
  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;
  1286 if term2str t = "(2 + -1 * x) / (3 + y)" then ()
  1300 if term2str t = "(2 + -1 * x) / (3 + y)" then ()
  1287 else error "rational.sml: diff.behav. in norm_Rational_mg 37b";
  1301 else error "rational.sml: diff.behav. in norm_Rational_mg 37b";
       
  1302 *)
  1288 
  1303 
  1289 "----- ?: worked before 0707xx";
  1304 "----- ?: worked before 0707xx";
  1290 val t = str2term "(3 + -1 * y) / (-9 + y ^^^ 2)";
  1305 val t = str2term "(3 + -1 * y) / (-9 + y ^^^ 2)";
  1291 val SOME (t,_) = rewrite_set_ thy false norm_Rational t;
  1306 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1292 if term2str t = "-1 / (3 + y)" then ()
  1307 if term2str t = "-1 / (3 + y)"
  1293 else error "rational.sml: -1 / (3 + y) norm_Rational";
  1308 then () else error "rational.sml: -1 / (3 + y) norm_Rational";
  1294 
  1309 
  1295 (*SRD Schalk I, p.69 Nr. 456b *)
  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
  1296 val t = str2term 
  1331 val t = str2term 
  1297 "(b^^^3 - b^^^2)/(b^^^2+b)/(b^^^2 - 1)";
  1332   ("(-1 * a ^^^ 2 + 2 * (a ^^^ 2 * x)) / (a * x + -1 * (b * x)) /" ^
  1298 val SOME (t,_) = rewrite_set_ thy false norm_Rational(*_mg*) t;
  1333   "((-1 * b ^^^ 2 + 2 * (b ^^^ 2 * x)) / (a * x + -1 * (b * x)))");
  1299 term2str t;
  1334 NONE = cancel_p_ thy t;
  1300 if (term2str t) = "b / (1 + 2 * b + b ^^^ 2)" then ()
  1335 
  1301 else error "rational.sml: diff.behav. in norm_Rational_mg 38";
       
  1302 
       
  1303 (*SRD Schalk I, p.69 Nr. 457b *)
       
  1304 val t = str2term 
       
  1305 "(16*a^^^2 - 9*b^^^2)/(2*a+3*a*b) / ((4*a+3*b)/(4*a^^^2 - 9*a^^^2*b^^^2))";
       
  1306 val SOME (t,_) = rewrite_set_ thy false norm_Rational(*_mg*) t;
       
  1307 term2str t;
       
  1308 if (term2str t) = 
       
  1309   "8 * a ^^^ 2 + -6 * a * b + -12 * a ^^^ 2 * b + 9 * a * b ^^^ 2"
       
  1310 then () else error "rational.sml: diff.behav. in norm_Rational_mg 39";
       
  1311 
       
  1312 "----- Schalk I, p.69 Nr. 458b works since 0707";
       
  1313 val t = str2term 
       
  1314 "(2*a^^^2*x - a^^^2)/(a*x - b*x) / (b^^^2*(2*x - 1)/(x*(a - b)))";
       
  1315 val SOME (t,_) = rewrite_set_ thy false norm_Rational t;
       
  1316 if term2str t = "a ^^^ 2 / b ^^^ 2" then ()
  1336 if term2str t = "a ^^^ 2 / b ^^^ 2" then ()
  1317 else error "rational.sml: diff.behav. in norm_Rational_mg 39b";
  1337 else error "rational.sml: diff.behav. in norm_Rational_mg 39b";
  1318 
  1338 *)
  1319 (*SRD Schalk I, p.69 Nr. 459b *)
  1339 
       
  1340 "----- SRD Schalk I, p.69 Nr. 459b";
  1320 val t = str2term "(a^^^2 - b^^^2)/(a*b) / (4*(a+b)^^^2/a)";
  1341 val t = str2term "(a^^^2 - b^^^2)/(a*b) / (4*(a+b)^^^2/a)";
  1321 val SOME (t,_) = rewrite_set_ thy false norm_Rational t;
  1342 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1322 if term2str t = "(a + -1 * b) / (4 * a * b + 4 * b ^^^ 2)" then ()
  1343 if term2str t = "(a + -1 * b) / (4 * a * b + 4 * b ^^^ 2)" then ()
  1323 else error "rational.sml: diff.behav. in norm_Rational_mg 41";
  1344 else error "rational.sml: diff.behav. in norm_Rational_mg 41";
  1324 
  1345 
  1325 
  1346 "----- Schalk I, p.69 Nr. 460b nonterm.SK";
  1326 (*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
  1327 val t = str2term 
  1352 val t = str2term 
  1328 "(9*(x^^^2 - 8*x+16)/(4*(y^^^2 - 2*y+1)))/((3*x - 12)/(16*y - 16))";
  1353   ("(144 + -72 * x + 9 * x ^^^ 2) / (4 + -8 * y + 4 * y ^^^ 2) /" ^
  1329 val SOME (t,_) = rewrite_set_ thy false norm_Rational(*_mg*) t;
  1354   "((-12 + 3 * x) / (-16 + 16 * y))");
  1330 if term2str t = 
  1355 NONE = cancel_p_ thy t;
  1331 then ()
  1356 
  1332 else error "rational.sml: diff.behav. in norm_Rational_mg 42";
  1357 if term2str t = !!!!!!!!!!!!!!!!!!!!!!!!!
  1333 
  1358 then () else error "rational.sml: diff.behav. in norm_Rational_mg 42";
  1334 val t = str2term 
  1359 *)
  1335 "9*(x^^^2 - 8*x+16)*(16*y - 16)/(4*(y^^^2 - 2*y+1)*(3*x - 12))";
  1360 
  1336 val SOME (t',_) = rewrite_set_ thy false norm_Rational t;
  1361 "----- some variant of the above; was non-terminating before";
  1337 ... non terminating.
  1362 val t = str2term "9*(x^^^2 - 8*x+16)*(16*y - 16)/(4*(y^^^2 - 2*y+1)*(3*x - 12))";
  1338 val SOME (t',_) = rewrite_set_ thy false make_polynomial t;
  1363 val SOME (t , _) = rewrite_set_ thy false norm_Rational t;
  1339 "(-2304 + 1152 * x + 2304 * y + -144 * x ^^^ 2 + -1152 * x * y + 144 * x ^^^ 2 * y) /(-48 + 12 * x + 96 * y + -24 * x * y + -48 * y ^^^ 2 + 12 * x * y ^^^ 2)";
  1364 if term2str t = "(48 + -12 * x) / (1 + -1 * y)"
  1340 val SOME (t,_) = rewrite_set_ thy false cancel_p t';
  1365 then () else error "some variant of the above; was non-terminating before";
  1341 ... non terminating.*)
  1366 
  1342 
  1367 "----- SRD Schalk I, p.70 Nr. 472a";
  1343 (*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))");
  1344 val t = str2term ("((8*x^^^2 - 32*y^^^2)/(2*x + 4*y))/" ^
  1369 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1345 		 "((4*x - 8*y)/(x + y))");
  1370 if term2str t = "x + y"
  1346 val SOME (t,_) = rewrite_set_ thy false norm_Rational(*_mg*) t;
  1371 then () else error "rational.sml: diff.behav. in norm_Rational_mg 43";
  1347 term2str t;
  1372 
  1348 if (term2str t) = 
  1373 "----- Schalk I, p.70 Nr. 478b ----- Rechenzeit: 5 sec";
  1349 "x + y"
  1374 val t = str2term ("(a - (a*b + b^^^2)/(a+b))/(b+(a - b)/(1+(a+b)/(a - b))) / " ^
  1350 then ()
  1375 		 "((a - a^^^2/(a+b))/(a+(a*b)/(a - b)))");
  1351 else error "rational.sml: diff.behav. in norm_Rational_mg 43";
  1376 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1352 
  1377 if term2str t = "(2 * a ^^^ 3 + 2 * a ^^^ 2 * b) / (a ^^^ 2 * b + b ^^^ 3)"
  1353 
  1378 then () else error "rational.sml: diff.behav. in norm_Rational_mg 51";
  1354 (*----------------------------------------------------------------------*)
       
  1355 (*---------------------- Einfache Dppelbrche --------------------------*)
       
  1356 (*----------------------------------------------------------------------*)
       
  1357 
  1379 
  1358 (*SRD Schalk I, p.69 Nr. 461a *)
  1380 (*SRD Schalk I, p.69 Nr. 461a *)
  1359 val t = str2term 
  1381 val t = str2term "(2/(x+3) + 2/(x - 3)) / (8*x/(x^^^2 - 9))";
  1360 "(2/(x+3) + 2/(x - 3)) / (8*x/(x^^^2 - 9))";
  1382 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1361 val SOME (t,_) = rewrite_set_ thy false norm_Rational(*_mg*) t;
  1383 if term2str t = "1 / 2"
  1362 term2str t;
  1384 then () else error "rational.sml: diff.behav. in norm_Rational_mg 44";
  1363 if (term2str t) = 
       
  1364 "1 / 2"
       
  1365 then ()
       
  1366 else error "rational.sml: diff.behav. in norm_Rational_mg 44";
       
  1367 
  1385 
  1368 (*SRD Schalk I, p.69 Nr. 464b *)
  1386 (*SRD Schalk I, p.69 Nr. 464b *)
  1369 val t = str2term 
  1387 val t = str2term "(a - a/(a - 2)) / (a + a/(a - 2))";
  1370 "(a - a/(a - 2)) / (a + a/(a - 2))";
  1388 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1371 val SOME (t,_) = rewrite_set_ thy false norm_Rational(*_mg*) t;
  1389 if term2str t = "(-3 + a) / (-1 + a)"
  1372 term2str t;
  1390 then () else error "rational.sml: diff.behav. in norm_Rational_mg 45";
  1373 if (term2str t) = 
       
  1374 "(3 + -1 * a) / (1 + -1 * a)"
       
  1375 then ()
       
  1376 else error "rational.sml: diff.behav. in norm_Rational_mg 45";
       
  1377 
  1391 
  1378 (*SRD Schalk I, p.69 Nr. 465b *)
  1392 (*SRD Schalk I, p.69 Nr. 465b *)
  1379 val t = str2term 
  1393 val t = str2term "((x+3*y)/9 + (4*y^^^2 - 9*z^^^2)/(16*x))   /   (x/9 + y/6 + z/4)";
  1380 "((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
  1381 val SOME (t,_) = rewrite_set_ thy false norm_Rational(*_mg*) t;
  1395   cancel_p_ thy (str2term 
  1382 term2str t;
  1396     ("("(576 * x ^^^ 2 + 1728 * (x * y) + 1296 * y ^^^ 2 + -2916 * z ^^^ 2) /" ^
  1383 if (term2str t) = 
  1397       "(576 * x ^^^ 2 + 864 * (x * y) + 1296 * (x * z))"))
  1384 "(4 * x + 6 * y + -9 * z) / (4 * x)"
  1398 
  1385 then ()
  1399 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1386 else error "rational.sml: diff.behav. in norm_Rational_mg 46";
  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 *)
  1387 
  1403 
  1388 (*SRD Schalk I, p.69 Nr. 466b *)
  1404 (*SRD Schalk I, p.69 Nr. 466b *)
  1389 val t = str2term 
  1405 val t = str2term "((1 - 7*(x - 2)/(x^^^2 - 4)) / (6/(x+2))) / (3/(x+5)+30/(x^^^2 - 25))";
  1390 "((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;
  1391 val SOME (t,_) = rewrite_set_ thy false norm_Rational(*_mg*) t;
  1407 if term2str t = "(25 + -10 * x + x ^^^ 2) / 18"
  1392 term2str t;
  1408 then () else error "rational.sml: diff.behav. in norm_Rational_mg 47";
  1393 if (term2str t) = 
       
  1394 "(25 + -10 * x + x ^^^ 2) / 18"
       
  1395 then ()
       
  1396 else error "rational.sml: diff.behav. in norm_Rational_mg 47";
       
  1397 
  1409 
  1398 (*SRD Schalk I, p.70 Nr. 469 *)
  1410 (*SRD Schalk I, p.70 Nr. 469 *)
  1399 val t = str2term 
  1411 val t = str2term ("3*b^^^2 / (4*a^^^2 - 8*a*b + 4*b^^^2) / " ^
  1400 "3*b^^^2/(4*a^^^2 - 8*a*b + 4*b^^^2)/(a/(a^^^2*b - b^^^3) + (a - b)/(4*a*b^^^2+4*b^^^3) - 1/(4*b^^^2))";
  1412   "(a / (a^^^2*b - b^^^3)  +  (a - b) / (4*a*b^^^2 + 4*b^^^3)  -  1 / (4*b^^^2))");
  1401 val SOME (t,_) = rewrite_set_ thy false norm_Rational(*_mg*) t;
  1413 val SOME (t, _) = rewrite_set_ thy false norm_Rational t;
  1402 term2str t;
  1414 if term2str t = "-3 * b ^^^ 3 / (-2 * a + 2 * b)"
  1403 if (term2str t) = 
  1415 then () else error "rational.sml: diff.behav. in norm_Rational_mg 48";
  1404 "3 * b ^^^ 3 / (2 * a + -2 * b)"
  1416 
  1405 then ()
  1417 "-------- me Schalk I No.186 -------------------------------------------------";
  1406 else error "rational.sml: diff.behav. in norm_Rational_mg 48";
  1418 "-------- me Schalk I No.186 -------------------------------------------------";
  1407 
  1419 "-------- me Schalk I No.186 -------------------------------------------------";
  1408 (*----------------------------------------------------------------------*)
  1420 val fmz = ["Term ((14 * x * y) / ( x * y ))", "normalform N"];
  1409 (*---------------------- Mehrfache Dppelbrueche ------------------------*)
       
  1410 (*----------------------------------------------------------------------*)
       
  1411 
       
  1412 (*SRD.test Schalk I, p.70 Nr. 476b *) (* Rechenzeit: 10 sec *)
       
  1413 (*WN060419 crashes with method 'simplify' ????SK*)
       
  1414 val t = str2term 
       
  1415 "((a^^^2 - b^^^2)/(2*a*b)+2*a*b/(a^^^2 - b^^^2))/((a^^^2+b^^^2)/(2*a*b)+1) / ((a^^^2+b^^^2)^^^2/(a+b)^^^2)";
       
  1416 val SOME (t,_) = rewrite_set_ thy false norm_Rational t;
       
  1417 if term2str t = "1 / (a ^^^ 2 + -1 * b ^^^ 2)" then ()
       
  1418 else error "rational.sml: diff.behav. in norm_Rational_mg 49";
       
  1419 
       
  1420 "----- Schalk I, p.70 Nr. 477a";
       
  1421 (* MG Achtung: terme explodieren; Bsp zu komplex; 
       
  1422    L???ung sollte (ziemlich grosser) Faktorisierter Ausdruck sein 
       
  1423 val t = str2term "b*y/(b - 2*y)/((b^^^2 - y^^^2)/(b+2*y)) /" ^
       
  1424 		 "(b^^^2*y+b*y^^^2)*(a+x)^^^2/((b^^^2 - 4*y^^^2)*(a+2*x)^^^2)";
       
  1425 val SOME (t',_) = rewrite_set_ thy false norm_Rational t;
       
  1426 
       
  1427 
       
  1428 val t = str2term "b*y*(b+2*y)*(b^^^2 - 4*y^^^2)*(a+2*x)^^^2 / " ^
       
  1429 		 "((b - 2*y)*(b^^^2 - y^^^2)*(b^^^2*y+b*y^^^2)*(a+x)^^^2)";
       
  1430 val SOME (t,_) = rewrite_set_ thy false make_polynomial t;
       
  1431 ????SK ???MG*)
       
  1432 
       
  1433 
       
  1434 "----- Schalk I, p.70 Nr. 478b ----- Rechenzeit: 5 sec";
       
  1435 val t = str2term ("(a - (a*b+b^^^2)/(a+b))/(b+(a - b)/(1+(a+b)/(a - b))) / " ^
       
  1436 		 "((a - a^^^2/(a+b))/(a+(a*b)/(a - b)))");
       
  1437 val SOME (t',_) = rewrite_set_ thy false norm_Rational(*_mg*) t;
       
  1438 if term2str t' = 
       
  1439 "(2 * a ^^^ 3 + 2 * a ^^^ 2 * b) / (a ^^^ 2 * b + b ^^^ 3)"
       
  1440 then ()
       
  1441 else error "rational.sml: diff.behav. in norm_Rational_mg 51";
       
  1442 
       
  1443 (* TODO.new_c:WN050820 STOP_REW_SUB introduced gave ...
       
  1444 if term2str t' = "(a ^^^ 4 + -1 * a ^^^ 2 * b ^^^ 2) /(a * b * (b + (a * (a + -1 * b) + -1 * b * (a + -1 * b)) / (2 * a)) * (a + -1 * b))" then ()
       
  1445 else error "rational.sml: works again";
       
  1446 re-outcommented with TODO.new_c: cvs before 071227, 11:50*)
       
  1447 
       
  1448 
       
  1449 
       
  1450 (*Schalk I, p.70 Nr. 480a *)
       
  1451 (* Achtung: rechnet ewig; cancel_p kann nicht krzen: WN060831 nonterm.SK00
       
  1452 val t = str2term 
       
  1453 "(1/x+1/y+1/z)/(1/x - 1/y - 1/z) / (2*x^^^2/(x^^^2 - z^^^2)/(x/(x+z)+x/(x - z)))";
       
  1454 val SOME (t,_) = rewrite_set_ thy false norm_Rational(*_mg*) t;
       
  1455 term2str t;
       
  1456 if (term2str t) = 
       
  1457 
       
  1458 then ()
       
  1459 else error "rational.sml: diff.behav. in norm_Rational_mg 52";
       
  1460 
       
  1461 (*MG Berechne Zwischenergebnisse: WN060831 nonterm.SK00*)
       
  1462 val t = str2term 
       
  1463 "(1/x+1/y+1/z)/(1/x - 1/y - 1/z)";
       
  1464 val SOME (t,_) = rewrite_set_ thy false norm_Rational(*_mg*) t;
       
  1465 term2str t;
       
  1466 "(x ^^^ 2 * y ^^^ 2 * z + x ^^^ 2 * y * z ^^^ 2 + x * y ^^^ 2 * z ^^^ 2) /
       
  1467 (-1 * x ^^^ 2 * y ^^^ 2 * z + -1 * x ^^^ 2 * y * z ^^^ 2 + x * y ^^^ 2 * z ^^^ 2)";
       
  1468 val t = str2term 
       
  1469 "2*x^^^2/(x^^^2 - z^^^2)/(x/(x+z)+x/(x - z))";
       
  1470 val SOME (t,_) = rewrite_set_ thy false norm_Rational(*_mg*) t;
       
  1471 term2str t;
       
  1472 "1"
       
  1473 
       
  1474 (* SK 1. Ausdruck kann nicht weiter gekrzt werden; cancel_p !!!*)
       
  1475 ###  rls: cancel_p on: 
       
  1476 (x ^^^ 2 * (y ^^^ 2 * z) + x ^^^ 2 * (y * z ^^^ 2) + x * (y ^^^ 2 * z ^^^ 2)) /
       
  1477 (-1 * (x ^^^ 2 * (y ^^^ 2 * z)) + -1 * (x ^^^ 2 * (y * z ^^^ 2)) + x * (y ^^^ 2 * z ^^^ 2))
       
  1478 GC #3.61.81.101.197.17503:   (0 ms)
       
  1479 *** RATIONALS_DIRECT_CANCEL_EXCEPTION: Invalid fraction
       
  1480 
       
  1481 val t = str2term 
       
  1482 "(x^^^2 * (y^^^2 * z) + x^^^2 * (y * z^^^2) + x * (y^^^2 * z^^^2)) / (-1 * (x^^^2 * (y^^^2 * z)) + -1 * (x^^^2 * (y * z^^^2)) + x * (y^^^2 * z^^^2))";
       
  1483 val SOME (t,_) = rewrite_set_ thy false cancel_p t;
       
  1484 term2str t;
       
  1485 (*uncaught exception nonexhaustive binding failure*)
       
  1486 
       
  1487 (* Das kann er aber krzen !!????: *)
       
  1488 val t = str2term 
       
  1489 "(x^^^2 * (y^^^2 * z) +  x * (y^^^2 * z^^^2)) / (-1 * (x^^^2 * (y * z^^^2)) + x * (y^^^2 * z^^^2))";
       
  1490 val SOME (t,_) = rewrite_set_ thy false cancel_p t;
       
  1491 term2str t;
       
  1492 "(-1 * (y * x) + -1 * (z * y)) / (1 * (z * x) + -1 * (z * y))";
       
  1493 *)
       
  1494 
       
  1495 
       
  1496 "-------- crucial examples ------------------------------";
       
  1497 "-------- crucial examples ------------------------------";
       
  1498 "-------- crucial examples ------------------------------";
       
  1499 (*Schalk I, p.60 Nr. 215d *)
       
  1500 (* Achtung: rechnet ewig ...
       
  1501 val t = str2term "(a-b)^^^3 * (x+y)^^^4 / ((x+y)^^^2 * (a-b)^^^5)";
       
  1502 val SOME (t,_) = rewrite_set_ thy false norm_Rational(*_mg*) t;
       
  1503 term2str t; noterm.SK
       
  1504 *)
       
  1505 
       
  1506 (* Kein Wunder, denn Z???ler und Nenner extra als Polynom dargestellt ergibt:*)
       
  1507 (*
       
  1508 val t = str2term "(a-b)^^^3 * (x+y)^^^4";
       
  1509 val SOME (t,_) = rewrite_set_ thy false norm_Rational(*_mg*) t;
       
  1510 term2str t;
       
  1511 "a^^^3 * x^^^4 + 4 * a^^^3 * x^^^3 * y +6 * a^^^3 * x^^^2 * y^^^2 +4 * a^^^3 * x * y^^^3 +a^^^3 * y^^^4 +-3 * a^^^2 * b * x^^^4 +-12 * a^^^2 * b * x^^^3 * y +-18 * a^^^2 * b * x^^^2 * y^^^2 +-12 * a^^^2 * b * x * y^^^3 +-3 * a^^^2 * b * y^^^4 +3 * a * b^^^2 * x^^^4 +12 * a * b^^^2 * x^^^3 * y +18 * a * b^^^2 * x^^^2 * y^^^2 +12 * a * b^^^2 * x * y^^^3 +3 * a * b^^^2 * y^^^4 +-1 * b^^^3 * x^^^4 +-4 * b^^^3 * x^^^3 * y +-6 * b^^^3 * x^^^2 * y^^^2 +-4 * b^^^3 * x * y^^^3 +-1 * b^^^3 * y^^^4";
       
  1512 val t = str2term "((x+y)^^^2 * (a-b)^^^5)";
       
  1513 val SOME (t,_) = rewrite_set_ thy false norm_Rational(*_mg*) t;
       
  1514 term2str t;
       
  1515 "a^^^5 * x^^^2 + 2 * a^^^5 * x * y + a^^^5 * y^^^2 +-5 * a^^^4 * b * x^^^2 +-10 * a^^^4 * b * x * y +-5 * a^^^4 * b * y^^^2 +10 * a^^^3 * b^^^2 * x^^^2 +20 * a^^^3 * b^^^2 * x * y +10 * a^^^3 * b^^^2 * y^^^2 +-10 * a^^^2 * b^^^3 * x^^^2 +-20 * a^^^2 * b^^^3 * x * y +-10 * a^^^2 * b^^^3 * y^^^2 +5 * a * b^^^4 * x^^^2 +10 * a * b^^^4 * x * y +5 * a * b^^^4 * y^^^2 +-1 * b^^^5 * x^^^2 +-2 * b^^^5 * x * y +-1 * b^^^5 * y^^^2";
       
  1516 *)
       
  1517 (*anscheinend macht dem Rechner das Krzen diese Bruches keinen Spass mehr ...*)
       
  1518 
       
  1519 (*--------------------------------------------------------------------*)
       
  1520 (*Schalk I, p.70 Nr. 480b 
       
  1521 val t = str2term "((12*x*y/(9*x^^^2 - y^^^2))/" ^
       
  1522 		 "(1/(3*x - y)^^^2 - 1/(3*x + y)^^^2)) *" ^
       
  1523 		 "(1/(x - 5*y)^^^2 - 1/(x + 5*y)^^^2)/" ^
       
  1524 		 "(20*x*y/(x^^^2 - 25*y^^^2))";
       
  1525 val SOME (t,_) = rewrite_set_ thy false norm_Rational(*_mg*) t;
       
  1526 SK.nonterm
       
  1527 Kann nicht weiter vereinfacht werden !!!!?? *)
       
  1528 
       
  1529 (*--------------------------------------------------------------------*)
       
  1530 "---- MGs test set";
       
  1531 val t = str2term " (1 + x^^^5) / (y + x) + x^^^3 / x ";
       
  1532 val SOME (t,_) = rewrite_set_ thy false common_nominator_p t;
       
  1533 if term2str t = "(1 + x ^^^ 3 + x ^^^ 5 + y * x ^^^ 2) / (x + y)" then()
       
  1534 else error "";
       
  1535 
       
  1536 (*--------------------------------------------------------------------*)
       
  1537 (* cancel_p liefert nicht immer Polynomnormalform (2): WN060831???SK3b
       
  1538    ---> Sortierung FALSCH !!  *)
       
  1539 val t = str2term "b^^^3 * a^^^5/a ";
       
  1540 val SOME (t,_) = rewrite_set_ thy false cancel_p t;
       
  1541 term2str t;
       
  1542 "1 * (a^^^4 * b^^^3) / 1"; (*OK*)
       
  1543 
       
  1544 val t = str2term "b^^^3 * a^^^5/b ";
       
  1545 val SOME (t,_) = rewrite_set_ thy false cancel_p t;
       
  1546 term2str t;
       
  1547 "1 * (b^^^2 * a^^^5) / 1"; (*cancel_p sortiert hier falsch um!*)
       
  1548 
       
  1549 (* Problem liegt NICHT bei ord_make_polynomial! (siehe folgende Bsple) *)
       
  1550 (*
       
  1551 val x = str2term "x"; val bdv = str2term "bdv";
       
  1552 val t1 = str2term "b^^^2 * a^^^5";
       
  1553 val t2 = str2term "a^^^5 * b^^^2 ";
       
  1554 ord_make_polynomial false Rational.thy [(x,bdv)] (t1,t2); (*false*)
       
  1555 *)
       
  1556 (* ==> "b^^^2 * a^^^5" > "a^^^5 * b^^^2 " ... OK!*)
       
  1557 
       
  1558 (*--------------------------------------------------------------------*)
       
  1559 (* cancel_p liefert nicht immer Polynomnormalform (2): WN060831???SK3c
       
  1560    ---> erzeugt berflssige "1 * ..."
       
  1561    
       
  1562 val t = str2term "-1 / (3 + y)";
       
  1563 (*~~         *)
       
  1564 val SOME (t,_) = rewrite_set_ thy false cancel_p t;
       
  1565 term2str t;
       
  1566 "-1 / (3 + 1 * y)";
       
  1567 (********* Das ist das PROBLEM !!!!!!!??? *******************)
       
  1568 (* -1 im Z???ler der Angabe verursacht das Problem !*)
       
  1569 *)
       
  1570 
       
  1571 (* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - *)
       
  1572 "----- MGs test set";
       
  1573 val t = str2term "(a^^^2 + -1)/(a+1)";
       
  1574 val SOME (t',_) = rewrite_set_ thy false cancel_p t;
       
  1575 if term2str t' = "(-1 + a) / 1" then ()
       
  1576 else error "rational.sml MG tests 3d";
       
  1577 
       
  1578 "----- NOT TERMINATING ?: worked before 0707xx";
       
  1579 val t = str2term "(a^^^2 - 1)*(b + 1) / ((b^^^2 - 1)*(a+1))";
       
  1580 val SOME (t'',_) = rewrite_set_ thy false norm_Rational t;
       
  1581 if term2str t'' = "(1 + -1 * a) / (1 + -1 * b)" then ()
       
  1582 else error "rational.sml MG tests 3e";
       
  1583 
       
  1584 "----- corrected SK060905";
       
  1585 val t = str2term "(4*x^^^2 - 20*x + 25)/(2*x - 5)^^^3";
       
  1586 val SOME (t',_) = rewrite_set_ thy false norm_Rational(*_mg*) t;
       
  1587 if term2str t' = "-1 / (5 + -2 * x)" then ()
       
  1588 else error "rational.sml corrected SK060905";
       
  1589 
       
  1590 
       
  1591 "-------- examples for Stefan Karnels thesis ------------";
       
  1592 "-------- examples for Stefan Karnels thesis ------------";
       
  1593 "-------- examples for Stefan Karnels thesis ------------";
       
  1594 (*SRAM Schalk I, p.69 Nr. 442b --- abgewandelt*)
       
  1595 val t = str2term 
       
  1596 "(15*a^^^4/(a*x^^^3) - 5*a*((b^^^4 - 5*c^^^2*x)/x^^^2))*(x^^^3/(5*a*b^^^3*c^^^3)) + a/c^^^3 * (x*(b/a) - 3*b*(a/b^^^4))";
       
  1597 val SOME (t,_) = rewrite_set_ thy false norm_Rational(*_mg*) t;
       
  1598 term2str t;
       
  1599 if (term2str t) =
       
  1600 "5 * x ^^^ 2 / (b ^^^ 3 * c)"
       
  1601 then ()
       
  1602 else error "rational.sml: diff.behav. in norm_Rational_mg 53";
       
  1603 
       
  1604 
       
  1605 "-------- me Schalk I No.186 ----------------------------";
       
  1606 "-------- me Schalk I No.186 ----------------------------";
       
  1607 "-------- me Schalk I No.186 ----------------------------";
       
  1608 val fmz = ["Term ((14 * x * y) / ( x * y ))",
       
  1609 	   "normalform N"];
       
  1610 val (dI',pI',mI') =
  1421 val (dI',pI',mI') =
  1611   ("Rational",["rational","simplification"],
  1422   ("Rational",["rational","simplification"],
  1612    ["simplification","of_rationals"]);
  1423    ["simplification","of_rationals"]);
  1613 val p = e_pos'; val c = []; 
  1424 val p = e_pos'; val c = []; 
  1614 val (p,_,f,nxt,_,pt) = CalcTreeTEST [(fmz, (dI',pI',mI'))];
  1425 val (p,_,f,nxt,_,pt) = CalcTreeTEST [(fmz, (dI',pI',mI'))];
  1625 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*)
  1626 case (f2str f, nxt) of
  1437 case (f2str f, nxt) of
  1627     ("14", ("End_Proof'", _)) => ()
  1438     ("14", ("End_Proof'", _)) => ()
  1628   | _ => error "rational.sml diff.behav. in me Schalk I No.186";
  1439   | _ => error "rational.sml diff.behav. in me Schalk I No.186";
  1629 
  1440 
  1630 
  1441 "-------- interSteps ..Simp_Rat_Double_No-1.xml ------------------------------";
  1631 "-------- interSteps ..Simp_Rat_Double_No-1.xml ---------";
  1442 "-------- interSteps ..Simp_Rat_Double_No-1.xml ------------------------------";
  1632 "-------- interSteps ..Simp_Rat_Double_No-1.xml ---------";
  1443 "-------- interSteps ..Simp_Rat_Double_No-1.xml ------------------------------";
  1633 "-------- interSteps ..Simp_Rat_Double_No-1.xml ---------";
       
  1634 states:=[];
  1444 states:=[];
  1635 CalcTree
  1445 CalcTree [(["Term (((2 - x)/(2*a)) / (2*a/(x - 2)))", "normalform N"], 
  1636 [(["Term (((2 - x)/(2*a)) / (2*a/(x - 2)))", "normalform N"], 
  1446   ("Rational", ["rational", "simplification"], ["simplification", "of_rationals"]))];
  1637   ("Rational",["rational","simplification"],
       
  1638   ["simplification","of_rationals"]))];
       
  1639 Iterator 1;
  1447 Iterator 1;
  1640 moveActiveRoot 1;
  1448 moveActiveRoot 1;
  1641 autoCalculate 1 CompleteCalc;
  1449 autoCalculate 1 CompleteCalc;
  1642 val ((pt,p),_) = get_calc 1; show_pt pt;
  1450 val ((pt, p), _) = get_calc 1; 
  1643 
  1451 (*
  1644 interSteps 1 ([1],Res);
  1452 show_pt pt;
  1645 val ((pt,p),_) = get_calc 1; show_pt pt;
  1453 [
  1646 
  1454 (([], Frm), Simplify ((2 - x) / (2 * a) / (2 * a / (x - 2)))),
  1647 
  1455 (([1], Frm), (2 - x) / (2 * a) / (2 * a / (x - 2))),
  1648 "-------- interSteps ..Simp_Rat_Cancel_No-1.xml ---------";
  1456 (([1], Res), (2 + -1 * x) / (2 * a) / (2 * a / (x + -1 * 2))),
  1649 "-------- interSteps ..Simp_Rat_Cancel_No-1.xml ---------";
  1457 (([2], Res), (2 + -1 * x) / (2 * a) / (2 * a / (-2 + x))),
  1650 "-------- interSteps ..Simp_Rat_Cancel_No-1.xml ---------";
  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 ------------------------------";
  1651 states:=[];
  1488 states:=[];
  1652 CalcTree
  1489 CalcTree [(["Term ((a^2 + -1*b^2) / (a^2 + -2*a*b + b^2))", "normalform N"], 
  1653 [(["Term ((a^2 + -1*b^2) / (a^2 + -2*a*b + b^2))", "normalform N"], 
  1490   ("Rational", ["rational", "simplification"], ["simplification", "of_rationals"]))];
  1654   ("Rational",["rational","simplification"],
       
  1655   ["simplification","of_rationals"]))];
       
  1656 Iterator 1;
  1491 Iterator 1;
  1657 moveActiveRoot 1;
  1492 moveActiveRoot 1;
  1658 autoCalculate 1 CompleteCalc;
  1493 autoCalculate 1 CompleteCalc;
  1659 val ((pt,p),_) = get_calc 1; show_pt pt;
  1494 val ((pt, p), _) = get_calc 1;
  1660 (*========== inhibit exn 110314 ================================================
  1495 (*show_pt pt;
  1661 (*with explicit script done already... and removed [1,..] at below...
  1496 [
  1662 interSteps 1 ([1],Res);
  1497 (([], Frm), Simplify ((a ^^^ 2 + -1 * b ^^^ 2) / (a ^^^ 2 + -2 * a * b + b ^^^ 2))),
  1663 val ((pt,p),_) = get_calc 1; show_pt pt;
  1498 (([1], Frm), (a ^^^ 2 + -1 * b ^^^ 2) / (a ^^^ 2 + -2 * a * b + b ^^^ 2)),
  1664 *)
  1499 (([1], Res), (a ^^^ 2 + -1 * b ^^^ 2) / (a ^^^ 2 + -2 * (a * b) + b ^^^ 2)),
  1665 interSteps 1 ([2],Res);
  1500 (([2], Res), (a + b) / (a + -1 * b)),
  1666 val ((pt,p),_) = get_calc 1; show_pt pt;
  1501 (([], Res), (a + b) / (a + -1 * b))] 
  1667 
  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 *)
  1668 interSteps 1 ([2,1],Res);
  1515 interSteps 1 ([2,1],Res);
  1669 val ((pt,p),_) = get_calc 1; show_pt pt;
  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 *)
  1670 val newnds = children (get_nd pt [2,1]) (*see "fun detailrls"*);
  1551 val newnds = children (get_nd pt [2,1]) (*see "fun detailrls"*);
  1671 (*if length newnds = 12 then () WN060905*)
  1552 if length newnds = 13 then () else error "rational.sml: interSteps cancel_p rev_rew_p";
  1672 if length newnds = 13 then ()
       
  1673 else error "rational.sml: interSteps cancel_p rev_rew_p";
       
  1674 
  1553 
  1675 val p = ([2,1,9],Res);
  1554 val p = ([2,1,9],Res);
  1676 getTactic 1 p;
  1555 getTactic 1 p;
  1677 val (_, tac, _) = pt_extract (pt, p);
  1556 val (_, tac, _) = pt_extract (pt, p);
  1678 (*case tac of SOME (Rewrite ("sym_real_plus_binom_times1", _)) => ()
  1557 case tac of SOME (Rewrite ("sym_distrib_left", _)) => ()
  1679 WN060905*)
       
  1680 case tac of SOME (Rewrite ("sym_real_add_mult_distrib2", _)) => ()
       
  1681 | _ => error "rational.sml: getTactic, sym_real_plus_binom_times1";
  1558 | _ => error "rational.sml: getTactic, sym_real_plus_binom_times1";
  1682 ============ inhibit exn 110314 ==============================================*)
  1559 
  1683 
  1560 
  1684 
  1561 "-------- investigate rulesets for cancel_p ----------------------------------";
  1685 "-------- investigate rulesets for cancel_p -------------";
  1562 "-------- investigate rulesets for cancel_p ----------------------------------";
  1686 "-------- investigate rulesets for cancel_p -------------";
  1563 "-------- investigate rulesets for cancel_p ----------------------------------";
  1687 "-------- investigate rulesets for cancel_p -------------";
       
  1688 val thy = @{theory "Rational"};
  1564 val thy = @{theory "Rational"};
  1689 "---------------- (a^^^2 + -1*b^^^2) / (a^^^2 + -2*a*b + b^^^2)";
       
  1690 val t = str2term "(a^^^2 + -1*b^^^2) / (a^^^2 + -2*a*b + b^^^2)";
  1565 val t = str2term "(a^^^2 + -1*b^^^2) / (a^^^2 + -2*a*b + b^^^2)";
  1691 val tt = str2term "(1 * a + 1 * b) * (1 * a + -1 * b)"(*numerator only*);
  1566 val tt = str2term "(1 * a + 1 * b) * (1 * a + -1 * b)"(*numerator only*);
       
  1567 
  1692 "----- with rewrite_set_";
  1568 "----- with rewrite_set_";
  1693 val SOME (tt',asm) = rewrite_set_ thy false make_polynomial tt;
  1569 val SOME (tt',asm) = rewrite_set_ thy false make_polynomial tt;
  1694 term2str tt'= "a ^^^ 2 + -1 * b ^^^ 2" (*true*);
  1570 if term2str tt'= "a ^^^ 2 + -1 * b ^^^ 2" then () else error "rls chancel_p 1";
  1695 val tt = str2term "((1 * a + -1 * b) * (1 * a + -1 * b))"(*denominator only*);
  1571 val tt = str2term "((1 * a + -1 * b) * (1 * a + -1 * b))"(*denominator only*);
  1696 val SOME (tt',asm) = rewrite_set_ thy false make_polynomial tt;
  1572 val SOME (tt',asm) = rewrite_set_ thy false make_polynomial tt;
  1697 term2str tt' = "a ^^^ 2 + -2 * a * b + b ^^^ 2" (*true*);
  1573 if term2str tt' = "a ^^^ 2 + -2 * a * b + b ^^^ 2" then () else error "rls chancel_p 2";
  1698 
  1574 
  1699 "----- with make_deriv";
  1575 "----- with make_deriv; WN1130912 not investigated further, will be discontinued";
  1700 val SOME (tt, _) = factout_p_ thy t; term2str tt =
  1576 val SOME (tt, _) = factout_p_ thy t; 
  1701 "(1 * a + 1 * b) * (1 * a + -1 * b) / ((1 * a + -1 * b) * (1 * a + -1 * b))";
  1577 if term2str tt = "(a + b) * (a + -1 * b) / ((a + -1 * b) * (a + -1 * b))"
  1702 (*
  1578 then () else error "rls chancel_p 3";
  1703 "--- with ruleset as before 060829";
  1579 term2str tt = "(1 * a + 1 * b) * (1 * a + -1 * b) / ((1 * a + -1 * b) * (1 * a + -1 * b))";
  1704 val {rules, rew_ord=(_,ro),...} =
  1580 
  1705     rep_rls (assoc_rls "make_polynomial");
  1581 "--- with simpler ruleset";
       
  1582 val {rules, rew_ord= (_, ro), ...} = rep_rls (assoc_rls "rev_rew_p");
  1706 val der = make_deriv thy Atools_erls rules ro NONE tt;
  1583 val der = make_deriv thy Atools_erls rules ro NONE tt;
  1707 print_depth 99; map (term2str o #1) der; print_depth 3;
  1584 if length der = 12 then () else error "WN1130912 rls chancel_p 4";
  1708 print_depth 99; map (rule2str o #2) der; print_depth 3;
       
  1709 ... did not terminate*)
       
  1710 "--- with simpler ruleset";
       
  1711 val {rules, rew_ord=(_,ro),...} =
       
  1712     rep_rls (assoc_rls "rev_rew_p");
       
  1713 val der = make_deriv thy Atools_erls rules ro NONE tt;
       
  1714 print_depth 99; writeln (deriv2str der); print_depth 3;
  1585 print_depth 99; writeln (deriv2str der); print_depth 3;
  1715 
  1586 
  1716 print_depth 99; map (term2str o #1) der; print_depth 3;
  1587 print_depth 99; map (term2str o #1) der; print_depth 3;
  1717 "...,(-1 * b ^^^ 2 + a ^^^ 2) / (-2 * (a * b) + a ^^^ 2 + (-1 * b) ^^^ 2) ]";
  1588 "...,(-1 * b ^^^ 2 + a ^^^ 2) / (-2 * (a * b) + a ^^^ 2 + (-1 * b) ^^^ 2) ]";
  1718 print_depth 99; map (rule2str o #2) der; print_depth 3;
  1589 print_depth 99; map (rule2str o #2) der; print_depth 3;
  1719 print_depth 99; map (term2str o #1 o #3) der; print_depth 3;
  1590 print_depth 99; map (term2str o #1 o #3) der; print_depth 3;
  1720 
  1591 
  1721 val der = make_deriv thy Atools_erls rules ro NONE 
  1592 val der = make_deriv thy Atools_erls rules ro NONE 
  1722 		     (str2term "(1 * a + 1 * b) * (1 * a + -1 * b)");
  1593 	(str2term "(1 * a + 1 * b) * (1 * a + -1 * b)");
  1723 print_depth 99; writeln (deriv2str der); print_depth 3;
  1594 print_depth 99; writeln (deriv2str der); print_depth 3;
  1724 
  1595 
  1725 val {rules, rew_ord=(_,ro),...} =
  1596 val {rules, rew_ord=(_,ro),...} = rep_rls (assoc_rls "rev_rew_p");
  1726     rep_rls (assoc_rls "rev_rew_p");
       
  1727 val der = make_deriv thy Atools_erls rules ro NONE 
  1597 val der = make_deriv thy Atools_erls rules ro NONE 
  1728 		     (str2term "(1 * a + -1 * b) * (1 * a + -1 * b)");
  1598 	(str2term "(1 * a + -1 * b) * (1 * a + -1 * b)");
  1729 print_depth 99; writeln (deriv2str der); print_depth 3;
  1599 print_depth 99; writeln (deriv2str der); print_depth 3;
  1730 print_depth 99; map (term2str o #1) der; print_depth 3;
  1600 print_depth 99; map (term2str o #1) der; print_depth 3;
  1731 (*WN060829 ...postponed*)
  1601 (*WN060829 ...postponed*)
  1732 
  1602 
  1733 
  1603 
  1734 "-------- investigate format of factout_ and factout_p_ -";
  1604 "-------- fun eval_get_denominator -------------------------------------------";
  1735 "-------- investigate format of factout_ and factout_p_ -";
  1605 "-------- fun eval_get_denominator -------------------------------------------";
  1736 "-------- investigate format of factout_ and factout_p_ -";
  1606 "-------- fun eval_get_denominator -------------------------------------------";
  1737 val {rules, rew_ord = (_,ro),...} = rep_rls (assoc_rls "make_polynomial");
       
  1738 val (thy, eval_rls) = (@{theory "Rational"}, Atools_erls)(*see 'fun init_state'*);
       
  1739 val Rrls {scr = Rfuns {init_state,...},...} = assoc_rls "cancel_p";
       
  1740 
       
  1741 "----- see Rational.ML, local cancel_p, fun init_state";
       
  1742 val t = str2term "(a^^^2 + (-1)*b^^^2) / (a^^^2 + (-2)*a*b + b^^^2)";
       
  1743 val SOME (t',_) = factout_p_ thy t; term2str t';
       
  1744 (*
       
  1745 val rtas = reverse_deriv thy eval_rls rules ro NONE t';
       
  1746 writeln(trtas2str rst);
       
  1747 *)
       
  1748 
       
  1749 
       
  1750 "----- see Rational.ML, local cancel_p, fun init_state";
       
  1751 val t = str2term "a^^^2 / a";
       
  1752 val SOME (t',_) = factout_p_ thy t; 
       
  1753 term2str t' = "a * a / (1 * a)" (*true*); 
       
  1754 (*... can be canceled with
       
  1755 real_mult_div_cancel2 ?k ~= 0 ==> ?m * ?k / (?n * ?k) = ?m / ?n"*)
       
  1756 (* sml/ME/rewtools.sml:
       
  1757 val rtas = reverse_deriv thy Atools_erls rules ro NONE t';
       
  1758 writeln (deri2str rtas);
       
  1759 *)
       
  1760 
       
  1761 
       
  1762 "-------- SK 060904 ----------------------------------------------";
       
  1763 "----- order on polynomials -- input + output";
       
  1764 val thy = @{theory "Isac"};
       
  1765 val t = str2term "(a + -1 * b) / (-1 * a + b)";
       
  1766 val SOME (t', _) = factout_p_ thy t; term2str t';
       
  1767 val SOME (t', _) = cancel_p_ thy t; term2str t';
       
  1768 
       
  1769 val t = str2term "a*b*c*d / (d*e*f*g)";
       
  1770 val SOME (t', _) = cancel_p_ thy t; term2str t';
       
  1771 
       
  1772 val t = str2term "a*(b*(c*d)) / (b*(e*(f*g)))";
       
  1773 val SOME (t', _) = cancel_p_ thy t; term2str t';
       
  1774 (*???order.SK  ???*)
       
  1775 
       
  1776 "----- SK060904-1a non-termination of cancel_p_ ? worked before 0707xx";
       
  1777 val t = str2term "(x^^^2 - 4)*(3 - y) / ((y^^^2 - 9)*(2+x))";
       
  1778 val SOME (t',_) = rewrite_set_ thy false norm_Rational t; 
       
  1779 if term2str t' = "(2 + -1 * x) / (3 + y)" then ()
       
  1780 else error "rational.sml SK060904-1a worked since 0707xx";
       
  1781 
       
  1782 "----- SK060904-1b non-termination of cancel_p_ ... worked before 0707xx";
       
  1783 val t = str2term ("(9 * a ^^^ 2 + -16 * b ^^^ 2) /" ^
       
  1784 "(36 * a^^^2 * c + (27 * a^^^2 * e + (-64 * b^^^2 * c + -48 * b^^^2 * e)))");
       
  1785 val SOME (t',_) = cancel_p_ thy t; 
       
  1786 if term2str t' = "1 / (4 * c + 3 * e)" then ()
       
  1787 else error "rational.sml SK060904-1b";
       
  1788 
       
  1789 
       
  1790 "----- SK060904-2a non-termination of add_fraction_p_";
       
  1791 val t = str2term (" (a + b * x) / (a + -1 * (b * x)) +  " ^
       
  1792 		  " (-1 * a + b * x) / (a + b * x)      ");
       
  1793 (* nonterm.SK
       
  1794 val SOME (t',_) = rewrite_set_ thy false common_nominator_p t;
       
  1795 
       
  1796 common_nominator_p_ thy t;
       
  1797 " (a + b * x)*(a + b * x) / ((a + -1 * (b * x))*(a + -1 * (b * x))) +  " ^
       
  1798 " (-1 * a + b * x)*(a + -1 * (b * x)) / ((a + b * x)*(-1 * a + b * x)) ";
       
  1799 
       
  1800 add_fraction_p_ thy t; 
       
  1801 " ((a + b * x)*(a + b * x)  +  (-1 * a + b * x)*(a + -1 * (b * x))) /" ^
       
  1802 " ((a + b * x)*(-1 * a + b * x))                                     ";
       
  1803 *)
       
  1804 
       
  1805 
       
  1806 "-------- how to stepwise construct Scripts -------------";
       
  1807 "-------- how to stepwise construct Scripts -------------";
       
  1808 "-------- how to stepwise construct Scripts -------------";
       
  1809 val thy = @{theory "Rational"};
       
  1810 (*no trailing _*)
       
  1811 val p1 = parse thy (
       
  1812 "Script SimplifyScript (t_t::real) =                             " ^
       
  1813 "  (Rewrite_Set discard_minus False                   " ^
       
  1814 "   t_t)");
       
  1815 
       
  1816 (*required (): (Rewrite_Set discard_minus False)*)
       
  1817 val p2 = parse thy (
       
  1818 "Script SimplifyScript (t_t::real) =                             " ^
       
  1819 "  (Rewrite_Set discard_minus False                   " ^
       
  1820 "   t_t)");
       
  1821 
       
  1822 val p3 = parse thy (
       
  1823 "Script SimplifyScript (t_t::real) =                             " ^
       
  1824 "  ((Rewrite_Set discard_minus False)                   " ^
       
  1825 "   t_t)");
       
  1826 
       
  1827 val p4 = parse thy (
       
  1828 "Script SimplifyScript (t_t::real) =                             " ^
       
  1829 "  ((Rewrite_Set discard_minus False)                   " ^
       
  1830 "   t_t)");
       
  1831 
       
  1832 val p5 = parse thy (
       
  1833 "Script SimplifyScript (t_t::real) =                             " ^
       
  1834 "  ((Try (Rewrite_Set discard_minus False)                   " ^
       
  1835 "    Try (Rewrite_Set discard_parentheses False))               " ^
       
  1836 "   t_t)");
       
  1837 
       
  1838 val p6 = parse thy (
       
  1839 "Script SimplifyScript (t_t::real) =                             " ^
       
  1840 "  ((Try (Rewrite_Set discard_minus False) @@                   " ^
       
  1841 "    Try (Rewrite_Set rat_mult_poly False) @@                    " ^
       
  1842 "    Try (Rewrite_Set make_rat_poly_with_parentheses False) @@   " ^
       
  1843 "    Try (Rewrite_Set cancel_p_rls False) @@                     " ^
       
  1844 "    (Repeat                                                     " ^
       
  1845 "     ((Try (Rewrite_Set common_nominator_p_rls False) @@        " ^
       
  1846 "       Try (Rewrite_Set rat_mult_div_pow False) @@              " ^
       
  1847 "       Try (Rewrite_Set make_rat_poly_with_parentheses False) @@" ^
       
  1848 "       Try (Rewrite_Set cancel_p_rls False) @@                  " ^
       
  1849 "       Try (Rewrite_Set rat_reduce_1 False)))) @@               " ^
       
  1850 "    Try (Rewrite_Set discard_parentheses False))               " ^
       
  1851 "   t_t)"
       
  1852 );
       
  1853 
       
  1854 "----------- get_denominator ----------------------------";
       
  1855 "----------- get_denominator ----------------------------";
       
  1856 "----------- get_denominator ----------------------------";
       
  1857 val thy = @{theory Isac};
  1607 val thy = @{theory Isac};
  1858 val t = term_of (the (parse thy "get_denominator ((a +x)/b)"));
  1608 val t = term_of (the (parse thy "get_denominator ((a +x)/b)"));
  1859 val SOME (_, t') = eval_get_denominator "" 0 t thy;
  1609 val SOME (_, t') = eval_get_denominator "" 0 t thy;
  1860 if term2str t' = "get_denominator ((a + x) / b) = b" then ()
  1610 if term2str t' = "get_denominator ((a + x) / b) = b"
  1861 else error "get_denominator ((a + x) / b) = b"
  1611 then () else error "get_denominator ((a + x) / b) = b"
  1862 
  1612 
  1863 
  1613 
  1864 "--------- several errpats in complicated term -------------------";
  1614 "-------- several errpats in complicated term --------------------------------";
  1865 "--------- several errpats in complicated term -------------------";
  1615 "-------- several errpats in complicated term --------------------------------";
  1866 "--------- several errpats in complicated term -------------------";
  1616 "-------- several errpats in complicated term --------------------------------";
  1867 (*TODO: instead of Gabriella's example here (27.Jul.12) find a simpler one*)
  1617 (*WN12xxxx TODO: instead of Gabriella's example here (27.Jul.12) find a simpler one
  1868 states:=[];
  1618   WN130912: kept this test, although not clear what for*)
  1869 CalcTree
  1619 states := [];
  1870 [(["Term ((5*b + 25)/(a^2 - b^2) * (a - b)/(5*b))", "normalform N"], 
  1620 CalcTree [(["Term ((5*b + 25)/(a^2 - b^2) * (a - b)/(5*b))", "normalform N"], 
  1871   ("Rational",["rational","simplification"], ["simplification","of_rationals"]))];
  1621   ("Rational", ["rational", "simplification"], ["simplification", "of_rationals"]))];
  1872 Iterator 1;
  1622 Iterator 1;
  1873 moveActiveRoot 1;
  1623 moveActiveRoot 1;
  1874 autoCalculate 1 CompleteCalc;
  1624 autoCalculate 1 CompleteCalc;
  1875 val ((pt,p),_) = get_calc 1; show_pt pt;
  1625 val ((pt, p), _) = get_calc 1;
  1876 
  1626 (*show_pt pt;
  1877 "-------- nonterminating cancel_p, norm_Rational 2002 ---";
  1627 [
  1878 "-------- nonterminating cancel_p, norm_Rational 2002 ---";
  1628 (([], Frm), Simplify ((5 * b + 25) / (a ^^^ 2 - b ^^^ 2) * (a - b) / (5 * b))),
  1879 "-------- nonterminating cancel_p, norm_Rational 2002 ---";
  1629 (([1], Frm), (5 * b + 25) / (a ^^^ 2 - b ^^^ 2) * (a - b) / (5 * b)),
  1880 (*------------------------------------------------------------------------------------\
  1630 (([1], Res), (5 * b + 25) / (a ^^^ 2 + -1 * b ^^^ 2) * (a + -1 * b) / (5 * b)),
  1881 "--- WN121204: searched rational.sml for "nonterm", added new numbering" ^
  1631 (([2], Res), (5 * b + 25) * (a + -1 * b) / (a ^^^ 2 + -1 * b ^^^ 2) / (5 * b)),
  1882 "              and thoroughly tested with this numbering subsequently";
  1632 (([3], Res), (25 * a + -25 * b + 5 * (a * b) + -5 * b ^^^ 2) / (a ^^^ 2 + -1 * b ^^^ 2) /
  1883 "--- 1 ---";
  1633 (5 * b)),
  1884 WN.2.6.03 from rlang.sml 56a 
  1634 (([4], Res), (25 + 5 * b) / (a + b) / (5 * b)),
  1885 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)";
  1635 (([5], Res), (25 + 5 * b) / ((a + b) * (5 * b))),
  1886 val NONE = rewrite_set_ thy false common_nominator_p t;
  1636 (([6], Res), (25 + 5 * b) / (5 * (a * b) + 5 * b ^^^ 2)),
  1887 "--- 2 ---";
  1637 (([7], Res), (5 + b) / (a * b + b ^^^ 2)),
  1888 WN060831 nonterm.SK7 
  1638 (([], Res), (5 + b) / (a * b + b ^^^ 2))] *)
  1889 val t = str2term "(a + b * x) / (a + -1 * (b * x)) + (-1 * a + b * x) / (a + b * x)";
  1639 
  1890 val NONE = add_fraction_p_ thy t;
  1640 
  1891 "--- 3 ---";
  1641 
  1892 nonterm.SK9 loops: cancel_p kann nicht weiter kuerzen!!! *)
       
  1893 val t'' = str2term "(a + b)/(x^^^2 - y^^^2) * ((x - y)^^^2/(a^^^2 - b^^^2))";
       
  1894 val SOME (t,_) = rewrite_set_ thy false norm_Rational(*_mg*) t'';
       
  1895 "--- 4 ---";
       
  1896 val t = str2term 
       
  1897 "(a * x ^^^ 2 + -2 * a * x * y + a * y ^^^ 2 + b * x ^^^ 2 + -2 * b * x * y + b * y ^^^ 2) /(a ^^^ 2 * x ^^^ 2 + -1 * a ^^^ 2 * y ^^^ 2 + -1 * b ^^^ 2 * x ^^^ 2 + b ^^^ 2 * y ^^^ 2)"; 
       
  1898 WN060831 nonterm.SK10 
       
  1899 val SOME (t,_) = rewrite_set_ thy false cancel_p t;
       
  1900 term2str t;
       
  1901 "--- 5 ---";
       
  1902 val t = str2term 
       
  1903 "(9*(x^^^2 - 8*x+16)/(4*(y^^^2 - 2*y+1)))/((3*x - 12)/(16*y - 16))";
       
  1904 val SOME (t,_) = rewrite_set_ thy false norm_Rational(*_mg*) t;
       
  1905 if term2str t = 
       
  1906 then ()
       
  1907 else error "rational.sml: diff.behav. in norm_Rational_mg 42";
       
  1908 "--- 6 ---";
       
  1909 val t = str2term 
       
  1910 "9*(x^^^2 - 8*x+16)*(16*y - 16)/(4*(y^^^2 - 2*y+1)*(3*x - 12))";
       
  1911 val SOME (t',_) = rewrite_set_ thy false norm_Rational t;
       
  1912 ... non terminating.
       
  1913 "--- 7 ---";
       
  1914 val SOME (t',_) = rewrite_set_ thy false make_polynomial t;
       
  1915 "(-2304 + 1152 * x + 2304 * y + -144 * x ^^^ 2 + -1152 * x * y + 144 * x ^^^ 2 * y) /(-48 + 12 * x + 96 * y + -24 * x * y + -48 * y ^^^ 2 + 12 * x * y ^^^ 2)";
       
  1916 val SOME (t,_) = rewrite_set_ thy false cancel_p t';
       
  1917 "--- 8 ---";
       
  1918 val t = str2term "(a-b)^^^3 * (x+y)^^^4 / ((x+y)^^^2 * (a-b)^^^5)";
       
  1919 val SOME (t,_) = rewrite_set_ thy false norm_Rational(*_mg*) t;
       
  1920 "--- 9 ---";
       
  1921 val t = str2term "((12*x*y/(9*x^^^2 - y^^^2))/" ^
       
  1922 		 "(1/(3*x - y)^^^2 - 1/(3*x + y)^^^2)) *" ^
       
  1923 		 "(1/(x - 5*y)^^^2 - 1/(x + 5*y)^^^2)/" ^
       
  1924 		 "(20*x*y/(x^^^2 - 25*y^^^2))";
       
  1925 val SOME (t,_) = rewrite_set_ thy false norm_Rational(*_mg*) t;
       
  1926 "--- 10 ---";
       
  1927 SK060904-2a non-termination of add_fraction_p_";
       
  1928 val t = str2term (" (a + b * x) / (a + -1 * (b * x)) +  " ^
       
  1929 		  " (-1 * a + b * x) / (a + b * x)      ");
       
  1930 (* nonterm.SK = WN130830
       
  1931 val SOME (t',_) = rewrite_set_ thy false common_nominator_p t;
       
  1932 "--- 11 ---";
       
  1933 common_nominator_p_ thy t;
       
  1934 " (a + b * x)*(a + b * x) / ((a + -1 * (b * x))*(a + -1 * (b * x))) +  " ^
       
  1935 " (-1 * a + b * x)*(a + -1 * (b * x)) / ((a + b * x)*(-1 * a + b * x)) ";
       
  1936 "--- 12 ---";                             
       
  1937 add_fraction_p_ thy t; 
       
  1938 " ((a + b * x)*(a + b * x)  +  (-1 * a + b * x)*(a + -1 * (b * x))) /" ^
       
  1939 " ((a + b * x)*(-1 * a + b * x))                                     ";
       
  1940 --------------------------------------------------------------------------------------/*)
       
  1941 
       
  1942 (*------------------------------------------------------------------------------------\
       
  1943 "WN121205: thoroughly tested with the above numbering.";
       
  1944 "  errors in cancel_p: --- 4,5,6,7.";
       
  1945 "  error in common_nominator_p, common_nominator_p_: --- 10; 1,2?.";
       
  1946 "  errors caused by ruleset norm_Rational: --- 8,9.";
       
  1947 trace_rewrite := false;
       
  1948 
       
  1949 "--- 1 ---: non-terminating with ### add_fract: done t22 "; = WN130830
       
  1950 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)";
       
  1951 trace_rewrite := false;
       
  1952 rewrite_set_ thy false common_nominator_p t;
       
  1953 
       
  1954 "--- 2 ---: non-terminating with ### add_fract: done t22 ";
       
  1955 val t = str2term "(a + b * x) / (a + -1 * (b * x)) + (-1 * a + b * x) / (a + b * x)";
       
  1956 add_fraction_p_ thy t;
       
  1957 
       
  1958 "--- 3 ---: norm_Rational calls Rrls cancel_p with non-normalised polys";
       
  1959 val t = str2term "(a + b)/(x^^^2 - y^^^2) * ((x - y)^^^2/(a^^^2 - b^^^2))";
       
  1960 rewrite_set_ thy false norm_Rational t;
       
  1961 (*tracing end...####  rls: cancel_p on: 
       
  1962 (a * x ^^^ 2 + -2 * (a * (x * y)) + a * y ^^^ 2 + b * x ^^^ 2 + -2 * (b * (x * y)) + b * y ^^^ 2) /
       
  1963 (a ^^^ 2 * x ^^^ 2 + -1 * (a ^^^ 2 * y ^^^ 2) + -1 * (b ^^^ 2 * x ^^^ 2) + b ^^^ 2 * y ^^^ 2) *)
       
  1964 
       
  1965 "--- 4 ---: non-terminating with Rrls cancel_p on plausible input";
       
  1966 val t = str2term (
       
  1967 "(a * x ^^^ 2 + -2 * a * x * y + a * y ^^^ 2 + b * x ^^^ 2 + -2 * b * x * y + b * y ^^^ 2) /"^
       
  1968 "(a ^^^ 2 * x ^^^ 2 + -1 * a ^^^ 2 * y ^^^ 2 + -1 * b ^^^ 2 * x ^^^ 2 + b ^^^ 2 * y ^^^ 2)"); 
       
  1969 rewrite_set_ thy false cancel_p t;
       
  1970 (*#  rls: cancel_p on: 
       
  1971 (a * x ^^^ 2 + -2 * a * x * y + a * y ^^^ 2 + b * x ^^^ 2 + -2 * b * x * y + b * y ^^^ 2) /
       
  1972 (a ^^^ 2 * x ^^^ 2 + -1 * a ^^^ 2 * y ^^^ 2 + -1 * b ^^^ 2 * x ^^^ 2 + b ^^^ 2 * y ^^^ 2) *)
       
  1973 
       
  1974 "--- 5 ---: non-terminating with Rrls cancel_p on plausible input";
       
  1975 val t = str2term "(9*(x^^^2 - 8*x+16)/(4*(y^^^2 - 2*y+1)))/((3*x - 12)/(16*y - 16))";
       
  1976 rewrite_set_ thy false norm_Rational t;
       
  1977 (*####  rls: cancel_p on: 
       
  1978 (2304 + -1152 * x + -2304 * y + 144 * x ^^^ 2 + 1152 * (x * y) + -144 * (x ^^^ 2 * y)) /
       
  1979 (48 + -12 * x + -96 * y + 24 * (x * y) + 48 * y ^^^ 2 + -12 * (x * y ^^^ 2))  *)
       
  1980 
       
  1981 "--- 6 ---: non-terminating with Rrls cancel_p on plausible input";
       
  1982 val t = str2term 
       
  1983 "9*(x^^^2 - 8*x+16)*(16*y - 16)/(4*(y^^^2 - 2*y+1)*(3*x - 12))";
       
  1984 rewrite_set_ thy false norm_Rational t;
       
  1985 (*###  rls: cancel_p on: (-2304 + 1152 * x + 2304 * y + -144 * x ^^^ 2 + -1152 * (x * y) +
       
  1986  144 * (x ^^^ 2 * y)) /
       
  1987 (-48 + 12 * x + 96 * y + -24 * (x * y) + -48 * y ^^^ 2 + 12 * (x * y ^^^ 2)) *)
       
  1988 
       
  1989 "--- 7 ---: non-terminating with Rrls cancel_p on plausible input";
       
  1990 val t' = str2term (
       
  1991 "(-2304 + 1152 * x + 2304 * y + -144 * x ^^^ 2 + -1152 * x * y + 144 * x ^^^ 2 * y) /"^
       
  1992 "(-48 + 12 * x + 96 * y + -24 * x * y + -48 * y ^^^ 2 + 12 * x * y ^^^ 2)");
       
  1993 rewrite_set_ thy false cancel_p t';
       
  1994 
       
  1995 "--- 8 ---: bottom of output cannot be looked ad (due to looping?)";
       
  1996 val t = str2term "(a-b)^^^3 * (x+y)^^^4 / ((x+y)^^^2 * (a-b)^^^5)";
       
  1997 val SOME (t,_) = rewrite_set_ thy false norm_Rational t;
       
  1998 
       
  1999 "--- 9 ---: probably error in norm_Rational";
       
  2000 val t = str2term (
       
  2001 "((12*x*y / (9*x^^^2 - y^^^2)) / (1/(3*x - y)^^^2 - 1/(3*x + y)^^^2)) *" ^
       
  2002 		"(1/(x - 5*y)^^^2 - 1/(x + 5*y)^^^2) / (20*x*y/(x^^^2 - 25*y^^^2))");
       
  2003 rewrite_set_ thy false norm_Rational t;
       
  2004 (*####  rls: cancel_p on: (19440 * (x ^^^ 8 * y ^^^ 2) + -490320 * (x ^^^ 6 * y ^^^ 4) +
       
  2005  108240 * (x ^^^ 4 * y ^^^ 6) +
       
  2006  -6000 * (x ^^^ 2 * y ^^^ 8)) /
       
  2007 (2160 * (x ^^^ 8 * y ^^^ 2) + -108240 * (x ^^^ 6 * y ^^^ 4) +
       
  2008  1362000 * (x ^^^ 4 * y ^^^ 6) +
       
  2009  -150000 * (x ^^^ 2 * y ^^^ 8)) *)
       
  2010 
       
  2011 "--- 10 ---: non-terminating with ### add_fract: done t22: error in common_nominator_p ";
       
  2012 val t = str2term (" (a + b * x) / (a + -1 * (b * x)) + (-1 * a + b * x) / (a + b * x)");
       
  2013 rewrite_set_ thy false common_nominator_p t; (*### add_fract: done t22 *)
       
  2014 common_nominator_p_ thy t;                   (*loops without output*)
       
  2015 "--- reformulated 10:";
       
  2016 val t = str2term "(a + -1 * (b * x)) / (a + b * x)";
       
  2017 rewrite_set_ thy false cancel_p t = NONE;
       
  2018 "--- 11 ---";
       
  2019 "--- 12 ---";                             
       
  2020 "...both are to be considered after common_nominator_p_ is improved";
       
  2021 --------------------------------------------------------------------------------------/*)
       
  2022 ============ inhibit exn WN130824 TODO ======================================================*)
       
  2023