src/Tools/isac/ProgLang/Prog_Expr.thy
author wneuper <walther.neuper@jku.at>
Mon, 03 May 2021 08:49:50 +0200
changeset 60275 98ee674d18d3
parent 60260 6a3b143d4cf4
child 60278 343efa173023
permissions -rw-r--r--
replace Isac's power with Isabelle's Transcendental.powr
     1 (* title:  ProgLang/Prog_Expr.thy
     2            functions for expressions (which do NOT contain Prog_Tac and Tactical, by definition))
     3    author: Walther Neuper, Aug.2019
     4    (c) copyright due to lincense terms.
     5 *)
     6 
     7 theory Prog_Expr
     8   imports Calculate ListC Program
     9 begin
    10 
    11 text \<open>Abstract:
    12   Specific constants are defined for pre-conditions of programs and for program-expressions.
    13   The constants are connected with ML functions for evaluation of respective expressions
    14   (all named eval_*), such that Isac's rewrite engine can handle it.
    15 \<close>
    16 
    17 subsection \<open>Power re-defined for a specific type\<close>
    18 abbreviation real_powr :: "real \<Rightarrow> real \<Rightarrow> real"  (infixr "\<up>" 80)
    19 where "x \<up> a \<equiv> x powr a"
    20 
    21 subsection \<open>consts of functions in pre-conditions and program-expressions\<close>
    22 consts
    23   lhs             :: "bool => real"           (*of an equality*)
    24   rhs             :: "bool => real"           (*of an equality*)
    25   Vars            :: "'a => real list"        (*get the variables of a term *)
    26   matches         :: "['a, 'a] => bool"
    27   matchsub        :: "['a, 'a] => bool"
    28   some'_occur'_in  :: "[real list, 'a] => bool" ("some'_of _ occur'_in _")
    29   occurs'_in       :: "[real     , 'a] => bool" ("_ occurs'_in _")
    30 
    31   abs              :: "real => real"            ("(|| _ ||)")
    32   (* ~~~ FIXXXME Isabelle2002 has abs already !!!*)
    33   absset           :: "real set => real"        ("(||| _ |||)")
    34   (*is numeral constant ?*)
    35   is'_const        :: "real => bool"            ("_ is'_const" 10)
    36   (*is_const rename to is_num FIXXXME.WN.16.5.03 *)
    37   is'_atom         :: "real => bool"            ("_ is'_atom" 10)
    38   is'_even         :: "real => bool"            ("_ is'_even" 10)
    39 		
    40   (* identity on term level*)
    41   ident            :: "['a, 'a] => bool"        ("(_ =!=/ _)" [51, 51] 50)
    42   argument'_in     :: "real => real"            ("argument'_in _" 10)
    43   sameFunId        :: "[real, bool] => bool"    (* "same'_funid _ _" 10
    44 	                    WN0609 changed the id, because ".. _ _" inhibits currying *)
    45   filter'_sameFunId:: "[real, bool list] => bool list" 
    46 					        ("filter'_sameFunId _ _" 10)
    47   boollist2sum     :: "bool list => real"
    48   lastI            :: "'a list \<Rightarrow> 'a"
    49 
    50 subsection \<open>ML code for functions in pre-conditions and program-expressions\<close>
    51 ML \<open>
    52 signature PROG_EXPR =
    53   sig
    54 (*//------------------------- from Tools .thy-------------------------------------------------\\*)
    55     val lhs: term -> term
    56     val eval_lhs: 'a -> string -> term -> 'b -> (string * term) option
    57     val eval_matches: string -> string -> term -> theory -> (string * term) option
    58     val matchsub: theory -> term -> term -> bool
    59     val eval_matchsub: string -> string -> term -> theory -> (string * term) option
    60     val rhs: term -> term
    61     val eval_rhs: 'a -> string -> term -> 'b -> (string * term) option
    62     val eval_var: string -> string -> term -> theory -> (string * term) option
    63 
    64     val or2list: term -> term
    65 (*\\------------------------- from Tools .thy-------------------------------------------------//*)
    66 (*//------------------------- from Atools .thy------------------------------------------------\\*)
    67     val occurs_in: term -> term -> bool
    68     val eval_occurs_in: 'a -> string -> term -> 'b -> (string * term) option
    69     val some_occur_in: term list -> term -> bool
    70     val eval_some_occur_in: 'a -> string -> term -> 'b -> (string * term) option
    71     val eval_is_atom: string -> string -> term -> 'a -> (string * term) option
    72     val even: int -> bool
    73     val eval_is_even: string -> string -> term -> 'a -> (string * term) option
    74     val eval_const: string -> string -> term -> 'a -> (string * term) option
    75     val eval_equ: string -> string -> term -> 'a -> (string * term) option
    76     val eval_ident: string -> string -> term -> theory -> (string * term) option
    77     val eval_equal: string -> string -> term -> theory -> (string * term) option
    78     val eval_cancel: string -> string -> term -> 'a -> (string * term) option
    79     val eval_argument_in: string -> string -> term -> 'a -> (string * term) option
    80     val same_funid: term -> term -> bool
    81     val eval_sameFunId: string -> string -> term -> 'a -> (string * term) option
    82     val eval_filter_sameFunId: string -> string -> term -> 'a -> (string * term) option
    83     val list2sum: term list -> term
    84     val eval_boollist2sum: string -> string -> term -> 'a -> (string * term) option
    85 
    86     val mk_thmid_f: string -> (int * int) * (int * int) -> (int * int) * (int * int) -> string
    87   end
    88 
    89 (**)
    90 structure Prog_Expr(**): PROG_EXPR =(**)
    91 struct
    92 (**)
    93 
    94 (*+ for Or_to_List +*)
    95 fun or2list (Const ("HOL.True",_)) = ((*tracing"### or2list True";*) UniversalList)
    96   | or2list (Const ("HOL.False",_)) = ((*tracing"### or2list False";*) EmptyList)
    97   | or2list (t as Const ("HOL.eq",_) $ _ $ _) = TermC.list2isalist HOLogic.boolT [t]
    98   | or2list ors =
    99     let
   100       fun get ls (Const ("HOL.disj",_) $ o1 $ o2) =
   101 	        (case o2 of
   102 	         	Const ("HOL.disj",_) $ _ $ _ => get (ls @ [o1]) o2
   103 	        | _ => ls @ [o1, o2])
   104         | get _ t = raise TERM ("or2list: missing pattern in fun.def", [t])
   105     in (((TermC.list2isalist HOLogic.boolT) o (get [])) ors) end
   106 (*>val t = @{term True};
   107 > val t' = or2list t;
   108 > term2str t';
   109 "ListC.UniversalList"
   110 > val t = @{term False};
   111 > val t' = or2list t;
   112 > term2str t';
   113 "[]"
   114 > val t=(Thm.term_of o the o (parse thy)) "x=3";
   115 > val t' = or2list t;
   116 > term2str t';
   117 "[x = 3]"
   118 > val t=(Thm.term_of o the o (parse thy))"(x=3) | (x=-3) | (x=0)";
   119 > val t' = or2list t;
   120 > term2str t';
   121 "[x = #3, x = #-3, x = #0]" : string *)
   122 
   123 
   124 (** evaluation on the meta-level **)
   125 
   126 (*. evaluate the predicate matches (match on whole term only) .*)
   127 (*("matches",("Prog_Expr.matches", eval_matches "#matches_")):calc*)
   128 fun eval_matches (_:string) "Prog_Expr.matches" (t as Const ("Prog_Expr.matches",_) $ pat $ tst) thy = 
   129     if TermC.matches thy tst pat
   130     then 
   131       let
   132         val prop = HOLogic.Trueprop $ (TermC.mk_equality (t, @{term True}))
   133 	    in SOME (UnparseC.term_in_thy thy prop, prop) end
   134     else 
   135       let 
   136         val prop = HOLogic.Trueprop $ (TermC.mk_equality (t, @{term False}))
   137 	    in SOME (UnparseC.term_in_thy thy prop, prop) end
   138   | eval_matches _ _ _ _ = NONE; 
   139 (*
   140 > val t  = (Thm.term_of o the o (parse thy)) 
   141 	      "matches (?x = 0) (1 * x \<up> 2 = 0)";
   142 > eval_matches "/thmid/" "/op_/" t thy;
   143 val it =
   144   SOME
   145     ("matches (x = 0) (1 * x \<up> 2 = 0) = False",
   146      Const (#,#) $ (# $ # $ Const #)) : (string * term) option
   147 
   148 > val t  = (Thm.term_of o the o (parse thy)) 
   149 	      "matches (?a = #0) (#1 * x \<up> #2 = #0)";
   150 > eval_matches "/thmid/" "/op_/" t thy;
   151 val it =
   152   SOME
   153     ("matches (?a = #0) (#1 * x \<up> #2 = #0) = True",
   154      Const (#,#) $ (# $ # $ Const #)) : (string * term) option
   155 
   156 > val t  = (Thm.term_of o the o (parse thy)) 
   157 	      "matches (?a * x = #0) (#1 * x \<up> #2 = #0)";
   158 > eval_matches "/thmid/" "/op_/" t thy;
   159 val it =
   160   SOME
   161     ("matches (?a * x = #0) (#1 * x \<up> #2 = #0) = False",
   162      Const (#,#) $ (# $ # $ Const #)) : (string * term) option
   163 
   164 > val t  = (Thm.term_of o the o (parse thy)) 
   165 	      "matches (?a * x \<up> #2 = #0) (#1 * x \<up> #2 = #0)";
   166 > eval_matches "/thmid/" "/op_/" t thy;
   167 val it =
   168   SOME
   169     ("matches (?a * x \<up> #2 = #0) (#1 * x \<up> #2 = #0) = True",
   170      Const (#,#) $ (# $ # $ Const #)) : (string * term) option                  
   171 ----- before ?patterns ---:
   172 > val t  = (Thm.term_of o the o (parse thy)) 
   173 	      "matches (a * b \<up> #2 = c) (#3 * x \<up> #2 = #1)";
   174 > eval_matches "/thmid/" "/op_/" t thy;
   175 SOME
   176     ("matches (a * b \<up> #2 = c) (#3 * x \<up> #2 = #1) = True",
   177      Const ("HOL.Trueprop", "bool => prop") $ (Const # $ (# $ #) $ Const (#,#)))
   178   : (string * term) option 
   179 
   180 > val t = (Thm.term_of o the o (parse thy)) 
   181 	      "matches (a * b \<up> #2 = c) (#3 * x \<up> #2222 = #1)";
   182 > eval_matches "/thmid/" "/op_/" t thy;
   183 SOME ("matches (a * b \<up> #2 = c) (#3 * x \<up> #2222 = #1) = False",
   184      Const ("HOL.Trueprop", "bool => prop") $ (Const # $ (# $ #) $ Const (#,#)))
   185 
   186 > val t = (Thm.term_of o the o (parse thy)) 
   187                "matches (a = b) (x + #1 + #-1 * #2 = #0)";
   188 > eval_matches "/thmid/" "/op_/" t thy;
   189 SOME ("matches (a = b) (x + #1 + #-1 * #2 = #0) = True",Const # $ (# $ #))
   190 *)
   191 
   192 (*.does a pattern match some subterm ?.*)
   193 fun matchsub thy t pat =  
   194   let
   195     fun matchs (t as Const _) = TermC.matches thy t pat
   196 	      | matchs (t as Free _) = TermC.matches thy t pat
   197 	      | matchs (t as Var _) = TermC.matches thy t pat
   198 	      | matchs (Bound _) = false
   199 	      | matchs (t as Abs (_, _, body)) = 
   200 	          if TermC.matches thy t pat then true else TermC.matches thy body pat
   201 	      | matchs (t as f1 $ f2) =
   202 	          if TermC.matches thy t pat then true 
   203 	            else if matchs f1 then true else matchs f2
   204   in matchs t end;
   205 
   206 (*("matchsub",("Prog_Expr.matchsub", eval_matchsub "#matchsub_")):calc*)
   207 fun eval_matchsub (_:string) "Prog_Expr.matchsub"
   208       (t as Const ("Prog_Expr.matchsub",_) $ pat $ tst) thy = 
   209     if matchsub thy tst pat
   210     then 
   211       let val prop = HOLogic.Trueprop $ (TermC.mk_equality (t, @{term True}))
   212       in SOME (UnparseC.term_in_thy thy prop, prop) end
   213     else 
   214       let val prop = HOLogic.Trueprop $ (TermC.mk_equality (t, @{term False}))
   215       in SOME (UnparseC.term_in_thy thy prop, prop) end
   216   | eval_matchsub _ _ _ _ = NONE; 
   217 
   218 (*get the variables in an isabelle-term*)
   219 (*("Vars"    ,("Prog_Expr.Vars"    , eval_var "#Vars_")):calc*)
   220 fun eval_var (thmid:string) "Prog_Expr.Vars" (t as (Const _ $ arg)) thy = 
   221     let 
   222       val t' = ((TermC.list2isalist HOLogic.realT) o TermC.vars) t;
   223       val thmId = thmid ^ UnparseC.term_in_thy thy arg;
   224     in SOME (thmId, HOLogic.Trueprop $ (TermC.mk_equality (t, t'))) end
   225   | eval_var _ _ _ _ = NONE;
   226 
   227 (* refer to Thm.lhs_of *)
   228 fun lhs (Const ("HOL.eq",_) $ l $ _) = l
   229   | lhs t = raise ERROR("lhs called with (" ^ UnparseC.term t ^ ")");
   230 (*("lhs"    ,("Prog_Expr.lhs"    , eval_lhs "")):calc*)
   231 fun eval_lhs _ "Prog_Expr.lhs" (t as (Const ("Prog_Expr.lhs",_) $ (Const ("HOL.eq",_) $ l $ _))) _ = 
   232     SOME ((UnparseC.term t) ^ " = " ^ (UnparseC.term l),
   233 	  HOLogic.Trueprop $ (TermC.mk_equality (t, l)))
   234   | eval_lhs _ _ _ _ = NONE;
   235 (*
   236 > val t = (Thm.term_of o the o (parse thy)) "lhs (1 * x \<up> 2 = 0)";
   237 > val SOME (id,t') = eval_lhs 0 0 t 0;
   238 val id = "Prog_Expr.lhs (1 * x \<up> 2 = 0) = 1 * x \<up> 2" : string
   239 > term2str t';
   240 val it = "Prog_Expr.lhs (1 * x \<up> 2 = 0) = 1 * x \<up> 2" : string
   241 *)
   242 
   243 fun rhs (Const ("HOL.eq",_) $ _ $ r) = r
   244   | rhs t = raise ERROR("rhs called with (" ^ UnparseC.term t ^ ")");
   245 (*("rhs"    ,("Prog_Expr.rhs"    , eval_rhs "")):calc*)
   246 fun eval_rhs _ "Prog_Expr.rhs" (t as (Const ("Prog_Expr.rhs",_) $ (Const ("HOL.eq",_) $ _ $ r))) _ = 
   247     SOME (UnparseC.term t ^ " = " ^ UnparseC.term r,
   248 	  HOLogic.Trueprop $ (TermC.mk_equality (t, r)))
   249   | eval_rhs _ _ _ _ = NONE;
   250 (*\\------------------------- from Prog_Expr.thy-------------------------------------------------//*)
   251 
   252 (*//------------------------- from Atools.thy------------------------------------------------\\*)
   253 fun occurs_in v t = member op = (((map strip_thy) o TermC.ids2str) t) (Term.term_name v);
   254 
   255 (*("occurs_in", ("Prog_Expr.occurs'_in", Prog_Expr.eval_occurs_in ""))*)
   256 fun eval_occurs_in _ "Prog_Expr.occurs'_in" (p as (Const ("Prog_Expr.occurs'_in",_) $ v $ t)) _ =
   257     ((*tracing("#>@ eval_occurs_in: v= "^(UnparseC.term v));
   258      tracing("#>@ eval_occurs_in: t= "^(UnparseC.term t));*)
   259      if occurs_in v t
   260     then SOME ((UnparseC.term p) ^ " = True",
   261 	  HOLogic.Trueprop $ (TermC.mk_equality (p, @{term True})))
   262     else SOME ((UnparseC.term p) ^ " = False",
   263 	  HOLogic.Trueprop $ (TermC.mk_equality (p, @{term False}))))
   264   | eval_occurs_in _ _ _ _ = NONE;
   265 
   266 (*some of the (bound) variables (eg. in an eqsys) "vs" occur in term "t"*)   
   267 fun some_occur_in vs t = 
   268     let fun occurs_in' a b = occurs_in b a
   269     in foldl or_ (false, map (occurs_in' t) vs) end;
   270 
   271 (*("some_occur_in", ("Prog_Expr.some'_occur'_in", 
   272 			eval_some_occur_in "#eval_some_occur_in_"))*)
   273 fun eval_some_occur_in _ "Prog_Expr.some'_occur'_in"
   274 			  (p as (Const ("Prog_Expr.some'_occur'_in",_) $ vs $ t)) _ =
   275     if some_occur_in (TermC.isalist2list vs) t
   276     then SOME ((UnparseC.term p) ^ " = True",
   277 	       HOLogic.Trueprop $ (TermC.mk_equality (p, @{term True})))
   278     else SOME ((UnparseC.term p) ^ " = False",
   279 	       HOLogic.Trueprop $ (TermC.mk_equality (p, @{term False})))
   280   | eval_some_occur_in _ _ _ _ = NONE;
   281 
   282 (*("is_atom",("Prog_Expr.is'_atom", Prog_Expr.eval_is_atom "#is_atom_"))*)
   283 fun eval_is_atom (thmid:string) "Prog_Expr.is'_atom"
   284 		 (t as (Const _ $ arg)) _ = 
   285     (case arg of 
   286 	 Free (n,_) => SOME (TermC.mk_thmid thmid n "", 
   287 			      HOLogic.Trueprop $ (TermC.mk_equality (t, @{term True})))
   288        | _ => SOME (TermC.mk_thmid thmid "" "", 
   289 		    HOLogic.Trueprop $ (TermC.mk_equality (t, @{term False}))))
   290   | eval_is_atom _ _ _ _ = NONE;
   291 
   292 fun even i = (i div 2) * 2 = i;
   293 (*("is_even",("Prog_Expr.is'_even", eval_is_even "#is_even_"))*)
   294 fun eval_is_even (thmid:string) "Prog_Expr.is'_even"
   295 		 (t as (Const _ $ arg)) _ = 
   296     (case arg of 
   297 	Free (n,_) =>
   298 	 (case ThmC_Def.int_opt_of_string n of
   299 	      SOME i =>
   300 	      if even i then SOME (TermC.mk_thmid thmid n "", 
   301 				   HOLogic.Trueprop $ (TermC.mk_equality (t, @{term True})))
   302 	      else SOME (TermC.mk_thmid thmid "" "", 
   303 			 HOLogic.Trueprop $ (TermC.mk_equality (t, @{term False})))
   304 	    | _ => NONE)
   305        | _ => NONE)
   306   | eval_is_even _ _ _ _ = NONE; 
   307 
   308 (*evaluate 'is_const'*)
   309 (*("is_const",("Prog_Expr.is'_const", Prog_Expr.eval_const "#is_const_"))*)
   310 fun eval_const (thmid:string) _ (t as (Const _ $ arg)) _ = 
   311     (case arg of 
   312        Const (n1, _) =>
   313 	     SOME (TermC.mk_thmid thmid n1 "", HOLogic.Trueprop $ (TermC.mk_equality (t, @{term False})))
   314      | Free (n1, _) =>
   315 	     if TermC.is_num' n1
   316 	     then SOME (TermC.mk_thmid thmid n1 "", HOLogic.Trueprop $ (TermC.mk_equality (t, @{term True})))
   317 	     else SOME (TermC.mk_thmid thmid n1 "", HOLogic.Trueprop $ (TermC.mk_equality (t, @{term False})))
   318      | _ => (*NONE*)
   319        SOME (TermC.mk_thmid thmid (UnparseC.term arg) "", HOLogic.Trueprop $ (TermC.mk_equality (t, @{term False}))))
   320   | eval_const _ _ _ _ = NONE; 
   321 
   322 (*. evaluate binary, associative, commutative operators: *,+,^ .*)
   323 (*("PLUS"    ,("Groups.plus_class.plus"        , (**)eval_binop "#add_")),
   324   ("TIMES"   ,("Groups.times_class.times"        , (**)eval_binop "#mult_")),
   325   ("POWER"  ,("Transcendental.powr"  , (**)eval_binop "#power_"))*)
   326 
   327 (* val (thmid,op_,t as(Const (op0,t0) $ Free (n1,t1) $ Free(n2,t2)),thy) =
   328        ("xxxxxx",op_,t,thy);
   329    *)
   330 fun mk_thmid_f thmid ((v11, v12), (p11, p12)) ((v21, v22), (p21, p22)) = (* dropped *)
   331   thmid ^ "Float ((" ^ 
   332   (string_of_int v11)^", "^(string_of_int v12)^"), ("^
   333   (string_of_int p11)^", "^(string_of_int p12)^")) __ (("^
   334   (string_of_int v21)^", "^(string_of_int v22)^"), ("^
   335   (string_of_int p21)^", "^(string_of_int p22)^"))";
   336 
   337 (*.evaluate < and <= for numerals.*)
   338 (*("le"      ,("Orderings.ord_class.less"        , Prog_Expr.eval_equ "#less_")),
   339   ("leq"     ,("Orderings.ord_class.less_eq"       , Prog_Expr.eval_equ "#less_equal_"))*)
   340 fun eval_equ (thmid:string) (_(*op_*)) (t as 
   341 	       (Const (op0, _) $ Free (n1, _) $ Free(n2, _))) _ = 
   342     (case (ThmC_Def.int_opt_of_string n1, ThmC_Def.int_opt_of_string n2) of
   343 	 (SOME n1', SOME n2') =>
   344   if Eval.calc_equ (strip_thy op0) (n1', n2')
   345     then SOME (TermC.mk_thmid thmid n1 n2, 
   346 	  HOLogic.Trueprop $ (TermC.mk_equality (t, @{term True})))
   347   else SOME (TermC.mk_thmid thmid n1 n2,  
   348 	  HOLogic.Trueprop $ (TermC.mk_equality (t, @{term False})))
   349        | _ => NONE)
   350     
   351   | eval_equ _ _ _ _ = NONE;
   352 
   353 
   354 (*evaluate identity
   355 > reflI;
   356 val it = "(?t = ?t) = True"
   357 > val t = str2term "x = 0";
   358 > val NONE = rewrite_ thy Rewrite_Ord.dummy_ord Rule_Set.empty false reflI t;
   359 
   360 > val t = str2term "1 = 0";
   361 > val NONE = rewrite_ thy Rewrite_Ord.dummy_ord Rule_Set.empty false reflI t;
   362 ----------- thus needs Rule.Eval !
   363 > val t = str2term "0 = 0";
   364 > val SOME (t',_) = rewrite_ thy Rewrite_Ord.dummy_ord Rule_Set.empty false reflI t;
   365 > UnparseC.term t';
   366 val it = "HOL.True"
   367 
   368 val t = str2term "Not (x = 0)";
   369 atomt t; UnparseC.term t;
   370 *** -------------
   371 *** Const ( Not)
   372 *** . Const ( op =)
   373 *** . . Free ( x, )
   374 *** . . Free ( 0, )
   375 val it = "x ~= 0" : string*)
   376 
   377 (*.evaluate identity on the term-level, =!= ,i.e. without evaluation of 
   378   the arguments: thus special handling by 'fun eval_binop'*)
   379 (*("ident"   ,("Prog_Expr.ident", Prog_Expr.eval_ident "#ident_")):calc*)
   380 fun eval_ident (thmid:string) "Prog_Expr.ident" (t as 
   381 	       (Const _(*op0, t0*) $ t1 $ t2 )) thy = 
   382   if t1 = t2
   383   then SOME (TermC.mk_thmid thmid 
   384 	              ("(" ^ (UnparseC.term_in_thy thy t1) ^ ")")
   385 	              ("(" ^ (UnparseC.term_in_thy thy t2) ^ ")"), 
   386 	     HOLogic.Trueprop $ (TermC.mk_equality (t, @{term True})))
   387   else SOME (TermC.mk_thmid thmid  
   388 	              ("(" ^ (UnparseC.term_in_thy thy t1) ^ ")")
   389 	              ("(" ^ (UnparseC.term_in_thy thy t2) ^ ")"),  
   390 	     HOLogic.Trueprop $ (TermC.mk_equality (t, @{term False})))
   391   | eval_ident _ _ _ _ = NONE;
   392 (* TODO
   393 > val t = str2term "x =!= 0";
   394 > val SOME (str, t') = eval_ident "ident_" "b" t thy;
   395 > UnparseC.term t';
   396 val str = "ident_(x)_(0)" : string
   397 val it = "(x =!= 0) = False" : string                                
   398 > val t = str2term "1 =!= 0";
   399 > val SOME (str, t') = eval_ident "ident_" "b" t thy;
   400 > UnparseC.term t';
   401 val str = "ident_(1)_(0)" : string 
   402 val it = "(1 =!= 0) = False" : string                                       
   403 > val t = str2term "0 =!= 0";
   404 > val SOME (str, t') = eval_ident "ident_" "b" t thy;
   405 > UnparseC.term t';
   406 val str = "ident_(0)_(0)" : string
   407 val it = "(0 =!= 0) = True" : string
   408 *)
   409 
   410 
   411 (* evaluate identity of terms, which stay ready for further evaluation;
   412   thus returns False only for atoms *)
   413 (*("equal"   ,("HOL.eq", Prog_Expr.eval_equal "#equal_")):calc*)
   414 fun eval_equal (thmid : string) "HOL.eq" (t as (Const _(*op0,t0*) $ t1 $ t2 )) thy = 
   415   if t1 = t2
   416   then
   417     SOME (TermC.mk_thmid thmid
   418       ("(" ^ UnparseC.term_in_thy thy t1 ^ ")") ("(" ^ UnparseC.term_in_thy thy t2 ^ ")"), 
   419       HOLogic.Trueprop $ (TermC.mk_equality (t, @{term True})))
   420   else
   421     (case (TermC.is_atom t1, TermC.is_atom t2) of
   422       (true, true) =>
   423         if TermC.variable_constant_pair (t1, t2)
   424         then NONE
   425         else SOME (TermC.mk_thmid thmid
   426           ("(" ^ UnparseC.term_in_thy thy t1 ^ ")") ("(" ^ UnparseC.term_in_thy thy t2 ^ ")"),
   427           HOLogic.Trueprop $ (TermC.mk_equality (t, @{term False})))
   428     | _ => NONE)                                              (* NOT is_atom t1,t2 --> rew_sub *)
   429   | eval_equal _ _ _ _ = NONE;                                                   (* error-exit *)
   430 
   431 (*. evaluate HOL.divide .*)
   432 (*("DIVIDE" ,("Rings.divide_class.divide"  , eval_cancel "#divide_e"))*)
   433 fun eval_cancel (thmid: string) "Rings.divide_class.divide" (t as 
   434 	       (Const (op0,t0) $ Free (n1, _) $ Free(n2, _))) _ = 
   435     (case (ThmC_Def.int_opt_of_string n1, ThmC_Def.int_opt_of_string n2) of
   436     	(SOME n1', SOME n2') =>
   437         let 
   438           val sg = Eval.sign_mult n1' n2';
   439           val (T1,T2,Trange) = TermC.dest_binop_typ t0;
   440           val gcd' = Eval.gcd (abs n1') (abs n2');
   441         in if gcd' = abs n2' 
   442            then let val rhs = TermC.term_of_num Trange (sg * (abs n1') div gcd')
   443     	        val prop = HOLogic.Trueprop $ (TermC.mk_equality (t, rhs))
   444     	    in SOME (TermC.mk_thmid thmid n1 n2, prop) end     
   445            else if 0 < n2' andalso gcd' = 1 then NONE
   446            else let val rhs = TermC.mk_num_op_num T1 T2 (op0,t0) (sg * (abs n1') div gcd')
   447     	  			   ((abs n2') div gcd')
   448     	        val prop = HOLogic.Trueprop $ (TermC.mk_equality (t, rhs))
   449     	    in SOME (TermC.mk_thmid thmid n1 n2, prop) end
   450         end
   451       | _ => ((*tracing"#>@ eval_cancel NONE";*)NONE))
   452   | eval_cancel _ _ _ _ = NONE;
   453 
   454 (* get the argument from a function-definition *)
   455 (*("argument_in" ,("Prog_Expr.argument'_in", Prog_Expr.eval_argument_in "Prog_Expr.argument'_in"))*)
   456 fun eval_argument_in _ "Prog_Expr.argument'_in" 
   457 		 (t as (Const ("Prog_Expr.argument'_in", _) $ (_(*f*) $ arg))) _ =
   458     if is_Free arg (*could be something to be simplified before*)
   459     then
   460       SOME (UnparseC.term t ^ " = " ^ UnparseC.term arg,
   461 	      HOLogic.Trueprop $ (TermC.mk_equality (t, arg)))
   462     else NONE
   463   | eval_argument_in _ _ _ _ = NONE;
   464 
   465 (* check if the function-identifier of the first argument matches 
   466    the function-identifier of the lhs of the second argument *)
   467 (*("sameFunId" ,("Prog_Expr.sameFunId", eval_same_funid "Prog_Expr.sameFunId"))*)
   468 fun eval_sameFunId _ "Prog_Expr.sameFunId" 
   469 		     (p as Const ("Prog_Expr.sameFunId",_) $  (f1 $ _) $ (Const ("HOL.eq", _) $ (f2 $ _) $ _)) _ =
   470     if f1 = f2 
   471     then SOME ((UnparseC.term p) ^ " = True",
   472 	       HOLogic.Trueprop $ (TermC.mk_equality (p, @{term True})))
   473     else SOME ((UnparseC.term p) ^ " = False",
   474 	       HOLogic.Trueprop $ (TermC.mk_equality (p, @{term False})))
   475 | eval_sameFunId _ _ _ _ = NONE;
   476 
   477 
   478 (*.from a list of fun-definitions "f x = ..." as 2nd argument
   479    filter the elements with the same fun-identfier in "f y"
   480    as the fst argument;
   481    this is, because Isabelles filter takes more than 1 sec.*)
   482 fun same_funid f1 (Const ("HOL.eq", _) $ (f2 $ _) $ _) = f1 = f2
   483   | same_funid f1 t = raise ERROR ("same_funid called with t = ("
   484 		  ^ UnparseC.term f1 ^ ") (" ^ UnparseC.term t ^ ")");
   485 (*("filter_sameFunId" ,("Prog_Expr.filter'_sameFunId",
   486 		   eval_filter_sameFunId "Prog_Expr.filter'_sameFunId"))*)
   487 fun eval_filter_sameFunId _ "Prog_Expr.filter'_sameFunId" 
   488 		     (p as Const ("Prog_Expr.filter'_sameFunId",_) $ 
   489 			(fid $ _) $ fs) _ =
   490     let val fs' = ((TermC.list2isalist HOLogic.boolT) o 
   491 		   (filter (same_funid fid))) (TermC.isalist2list fs)
   492     in SOME (UnparseC.term (TermC.mk_equality (p, fs')),
   493 	       HOLogic.Trueprop $ (TermC.mk_equality (p, fs'))) end
   494 | eval_filter_sameFunId _ _ _ _ = NONE;
   495 
   496 (* make a list of terms to a sum *)
   497 fun list2sum [] = raise ERROR ("list2sum called with []")
   498   | list2sum [s] = s
   499   | list2sum (s::ss) = 
   500     let
   501       fun sum su [s'] = Const ("Groups.plus_class.plus",
   502            [HOLogic.realT,HOLogic.realT] ---> HOLogic.realT) $ su $ s'
   503     	  | sum su (s'::ss') = sum (Const ("Groups.plus_class.plus",
   504            [HOLogic.realT,HOLogic.realT] ---> HOLogic.realT) $ su $ s') ss'
   505     	  | sum _ _ = raise ERROR "list2sum: pattern in fun.def is missing" 
   506     in sum s ss end;
   507 
   508 (* make a list of equalities to the sum of the lhs *)
   509 (*("boollist2sum"    ,("Prog_Expr.boollist2sum"    , eval_boollist2sum "")):calc*)
   510 fun eval_boollist2sum _ "Prog_Expr.boollist2sum" 
   511 		  (p as Const ("Prog_Expr.boollist2sum", _) $ (l as Const ("List.list.Cons", _) $ _ $ _)) _ =
   512     let
   513       val isal = TermC.isalist2list l
   514 	    val lhss = map lhs isal
   515 	    val sum = list2sum lhss
   516     in
   517       SOME ((UnparseC.term p) ^ " = " ^ (UnparseC.term sum),
   518 	      HOLogic.Trueprop $ (TermC.mk_equality (p, sum)))
   519     end
   520   | eval_boollist2sum _ _ _ _ = NONE;
   521 
   522 (**) end (*struct*)
   523 \<close> text \<open>
   524 open Prog_Expr
   525 \<close> ML \<open>
   526 \<close> ML \<open>
   527 \<close>
   528 
   529 subsection \<open>extend rule-set for evaluating pre-conditions and program-expressions\<close>
   530 ML \<open>
   531 val prog_expr = Rule_Set.append_rules "prog_expr" prog_expr [Rule.Eval ("Prog_Expr.rhs", Prog_Expr.eval_rhs "")];
   532 \<close> ML \<open>
   533 \<close> ML \<open>
   534 \<close>
   535 
   536 subsection \<open>setup for rule-sets and ML-functions\<close>
   537 setup \<open>KEStore_Elems.add_rlss [("prog_expr", (Context.theory_name @{theory}, prog_expr))]\<close>
   538 setup \<open>KEStore_Elems.add_calcs
   539   [("matches", ("Prog_Expr.matches", Prog_Expr.eval_matches "#matches_")),
   540     ("matchsub", ("Prog_Expr.matchsub", Prog_Expr.eval_matchsub "#matchsub_")),
   541     ("Vars", ("Prog_Expr.Vars", Prog_Expr.eval_var "#Vars_")),
   542     ("lhs", ("Prog_Expr.lhs", Prog_Expr.eval_lhs "")),
   543     ("rhs", ("Prog_Expr.rhs", Prog_Expr.eval_rhs ""))]\<close>
   544 (*\\------------------------- from Tools .thy-------------------------------------------------//*)
   545 ML \<open>
   546 \<close> ML \<open>
   547 \<close> ML \<open>
   548 \<close>
   549 
   550 end