src/Tools/isac/ProgLang/Prog_Expr.thy
author Walther Neuper <walther.neuper@jku.at>
Sat, 14 Sep 2019 16:15:05 +0200
changeset 59619 a2f67c777ccd
parent 59618 80efccb7e5c1
child 59620 086e4d9967a3
permissions -rw-r--r--
lucin: cleanup and comment thys in ProgLang
     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
     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 consts
    19   pow              :: "[real, real] => real"    (infixr "^^^" 80)
    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 EmptyList: term
    56     val UniversalList: term
    57 
    58     val lhs: term -> term
    59     val eval_lhs: 'a -> string -> term -> 'b -> (string * term) option
    60     val eval_matches: string -> string -> term -> theory -> (string * term) option
    61     val matchsub: theory -> term -> term -> bool
    62     val eval_matchsub: string -> string -> term -> theory -> (string * term) option
    63     val rhs: term -> term
    64     val eval_rhs: 'a -> string -> term -> 'b -> (string * term) option
    65     val eval_var: string -> string -> term -> theory -> (string * term) option
    66 
    67     val or2list: term -> term
    68 (*\\------------------------- from Tools .thy-------------------------------------------------//*)
    69 (*//------------------------- from Atools .thy------------------------------------------------\\*)
    70     val occurs_in: term -> term -> bool
    71     val eval_occurs_in: 'a -> string -> term -> 'b -> (string * term) option
    72     val some_occur_in: term list -> term -> bool
    73     val eval_some_occur_in: 'a -> string -> term -> 'b -> (string * term) option
    74     val eval_is_atom: string -> string -> term -> 'a -> (string * term) option
    75     val even: int -> bool
    76     val eval_is_even: string -> string -> term -> 'a -> (string * term) option
    77     val eval_const: string -> string -> term -> 'a -> (string * term) option
    78     val eval_equ: string -> string -> term -> 'a -> (string * term) option
    79     val eval_ident: string -> string -> term -> theory -> (string * term) option
    80     val eval_equal: string -> string -> term -> theory -> (string * term) option
    81     val eval_cancel: string -> string -> term -> 'a -> (string * term) option
    82     val eval_argument_in: string -> string -> term -> 'a -> (string * term) option
    83     val same_funid: term -> term -> bool
    84     val eval_sameFunId: string -> string -> term -> 'a -> (string * term) option
    85     val eval_filter_sameFunId: string -> string -> term -> 'a -> (string * term) option
    86     val list2sum: term list -> term
    87     val eval_boollist2sum: string -> string -> term -> 'a -> (string * term) option
    88 
    89     val mk_thmid_f: string -> (int * int) * (int * int) -> (int * int) * (int * int) -> string
    90 (*\\------------------------- from Atools.thy------------------------------------------------//*)
    91   end
    92 
    93 (**)
    94 structure Prog_Expr(**): PROG_EXPR =(**)
    95 struct
    96 (**)
    97 (*//------------------------- from Tools .thy-------------------------------------------------\\*)
    98 (* auxiliary functions for scripts  WN.9.00*)
    99 (*11.02: for equation solving only*)
   100 val UniversalList = (Thm.term_of o the o (TermC.parse @{theory})) "UniversalList";
   101 val EmptyList = (Thm.term_of o the o (TermC.parse @{theory}))  "[]::bool list";     
   102 
   103 (*+ for Or_to_List +*)
   104 fun or2list (Const ("HOL.True",_)) = (tracing"### or2list True";UniversalList)
   105   | or2list (Const ("HOL.False",_)) = (tracing"### or2list False";EmptyList)
   106   | or2list (t as Const ("HOL.eq",_) $ _ $ _) = TermC.list2isalist HOLogic.boolT [t]
   107   | or2list ors =
   108     let
   109       fun get ls (Const ("HOL.disj",_) $ o1 $ o2) =
   110 	        (case o2 of
   111 	         	Const ("HOL.disj",_) $ _ $ _ => get (ls @ [o1]) o2
   112 	        | _ => ls @ [o1, o2])
   113         | get _ t = raise TERM ("or2list: missing pattern in fun.def", [t])
   114     in (((TermC.list2isalist HOLogic.boolT) o (get [])) ors) end
   115 (*>val t = @{term True};
   116 > val t' = or2list t;
   117 > term2str t';
   118 "Prog_Expr.UniversalList"
   119 > val t = @{term False};
   120 > val t' = or2list t;
   121 > term2str t';
   122 "[]"
   123 > val t=(Thm.term_of o the o (parse thy)) "x=3";
   124 > val t' = or2list t;
   125 > term2str t';
   126 "[x = 3]"
   127 > val t=(Thm.term_of o the o (parse thy))"(x=3) | (x=-3) | (x=0)";
   128 > val t' = or2list t;
   129 > term2str t';
   130 "[x = #3, x = #-3, x = #0]" : string *)
   131 
   132 
   133 (** evaluation on the meta-level **)
   134 
   135 (*. evaluate the predicate matches (match on whole term only) .*)
   136 (*("matches",("Prog_Expr.matches", eval_matches "#matches_")):calc*)
   137 fun eval_matches (_:string) "Prog_Expr.matches"
   138 		  (t as Const ("Prog_Expr.matches",_) $ pat $ tst) thy = 
   139     if TermC.matches thy tst pat
   140     then 
   141       let
   142         val prop = HOLogic.Trueprop $ (TermC.mk_equality (t, @{term True}))
   143 	    in SOME (Rule.term_to_string''' thy prop, prop) end
   144     else 
   145       let 
   146         val prop = HOLogic.Trueprop $ (TermC.mk_equality (t, @{term False}))
   147 	    in SOME (Rule.term_to_string''' thy prop, prop) end
   148   | eval_matches _ _ _ _ = NONE; 
   149 (*
   150 > val t  = (Thm.term_of o the o (parse thy)) 
   151 	      "matches (?x = 0) (1 * x ^^^ 2 = 0)";
   152 > eval_matches "/thmid/" "/op_/" t thy;
   153 val it =
   154   SOME
   155     ("matches (x = 0) (1 * x ^^^ 2 = 0) = False",
   156      Const (#,#) $ (# $ # $ Const #)) : (string * term) option
   157 
   158 > val t  = (Thm.term_of o the o (parse thy)) 
   159 	      "matches (?a = #0) (#1 * x ^^^ #2 = #0)";
   160 > eval_matches "/thmid/" "/op_/" t thy;
   161 val it =
   162   SOME
   163     ("matches (?a = #0) (#1 * x ^^^ #2 = #0) = True",
   164      Const (#,#) $ (# $ # $ Const #)) : (string * term) option
   165 
   166 > val t  = (Thm.term_of o the o (parse thy)) 
   167 	      "matches (?a * x = #0) (#1 * x ^^^ #2 = #0)";
   168 > eval_matches "/thmid/" "/op_/" t thy;
   169 val it =
   170   SOME
   171     ("matches (?a * x = #0) (#1 * x ^^^ #2 = #0) = False",
   172      Const (#,#) $ (# $ # $ Const #)) : (string * term) option
   173 
   174 > val t  = (Thm.term_of o the o (parse thy)) 
   175 	      "matches (?a * x ^^^ #2 = #0) (#1 * x ^^^ #2 = #0)";
   176 > eval_matches "/thmid/" "/op_/" t thy;
   177 val it =
   178   SOME
   179     ("matches (?a * x ^^^ #2 = #0) (#1 * x ^^^ #2 = #0) = True",
   180      Const (#,#) $ (# $ # $ Const #)) : (string * term) option                  
   181 ----- before ?patterns ---:
   182 > val t  = (Thm.term_of o the o (parse thy)) 
   183 	      "matches (a * b^^^#2 = c) (#3 * x^^^#2 = #1)";
   184 > eval_matches "/thmid/" "/op_/" t thy;
   185 SOME
   186     ("matches (a * b ^^^ #2 = c) (#3 * x ^^^ #2 = #1) = True",
   187      Const ("HOL.Trueprop","bool => prop") $ (Const # $ (# $ #) $ Const (#,#)))
   188   : (string * term) option 
   189 
   190 > val t = (Thm.term_of o the o (parse thy)) 
   191 	      "matches (a * b^^^#2 = c) (#3 * x^^^#2222 = #1)";
   192 > eval_matches "/thmid/" "/op_/" t thy;
   193 SOME ("matches (a * b ^^^ #2 = c) (#3 * x ^^^ #2222 = #1) = False",
   194      Const ("HOL.Trueprop","bool => prop") $ (Const # $ (# $ #) $ Const (#,#)))
   195 
   196 > val t = (Thm.term_of o the o (parse thy)) 
   197                "matches (a = b) (x + #1 + #-1 * #2 = #0)";
   198 > eval_matches "/thmid/" "/op_/" t thy;
   199 SOME ("matches (a = b) (x + #1 + #-1 * #2 = #0) = True",Const # $ (# $ #))
   200 *)
   201 
   202 (*.does a pattern match some subterm ?.*)
   203 fun matchsub thy t pat =  
   204   let
   205     fun matchs (t as Const _) = TermC.matches thy t pat
   206 	      | matchs (t as Free _) = TermC.matches thy t pat
   207 	      | matchs (t as Var _) = TermC.matches thy t pat
   208 	      | matchs (Bound _) = false
   209 	      | matchs (t as Abs (_, _, body)) = 
   210 	          if TermC.matches thy t pat then true else TermC.matches thy body pat
   211 	      | matchs (t as f1 $ f2) =
   212 	          if TermC.matches thy t pat then true 
   213 	            else if matchs f1 then true else matchs f2
   214   in matchs t end;
   215 
   216 (*("matchsub",("Prog_Expr.matchsub", eval_matchsub "#matchsub_")):calc*)
   217 fun eval_matchsub (_:string) "Prog_Expr.matchsub"
   218 		  (t as Const ("Prog_Expr.matchsub",_) $ pat $ tst) thy = 
   219     if matchsub thy tst pat
   220     then 
   221       let val prop = HOLogic.Trueprop $ (TermC.mk_equality (t, @{term True}))
   222       in SOME (Rule.term_to_string''' thy prop, prop) end
   223     else 
   224       let val prop = HOLogic.Trueprop $ (TermC.mk_equality (t, @{term False}))
   225       in SOME (Rule.term_to_string''' thy prop, prop) end
   226   | eval_matchsub _ _ _ _ = NONE; 
   227 
   228 (*get the variables in an isabelle-term*)
   229 (*("Vars"    ,("Prog_Expr.Vars"    , eval_var "#Vars_")):calc*)
   230 fun eval_var (thmid:string) "Prog_Expr.Vars" (t as (Const _ $ arg)) thy = 
   231     let 
   232       val t' = ((TermC.list2isalist HOLogic.realT) o TermC.vars) t;
   233       val thmId = thmid ^ Rule.term_to_string''' thy arg;
   234     in SOME (thmId, HOLogic.Trueprop $ (TermC.mk_equality (t, t'))) end
   235   | eval_var _ _ _ _ = NONE;
   236 
   237 fun lhs (Const ("HOL.eq",_) $ l $ _) = l
   238   | lhs t = error("lhs called with (" ^ Rule.term2str t ^ ")");
   239 (*("lhs"    ,("Prog_Expr.lhs"    , eval_lhs "")):calc*)
   240 fun eval_lhs _ "Prog_Expr.lhs"
   241 	     (t as (Const ("Prog_Expr.lhs",_) $ (Const ("HOL.eq",_) $ l $ _))) _ = 
   242     SOME ((Rule.term2str t) ^ " = " ^ (Rule.term2str l),
   243 	  HOLogic.Trueprop $ (TermC.mk_equality (t, l)))
   244   | eval_lhs _ _ _ _ = NONE;
   245 (*
   246 > val t = (Thm.term_of o the o (parse thy)) "lhs (1 * x ^^^ 2 = 0)";
   247 > val SOME (id,t') = eval_lhs 0 0 t 0;
   248 val id = "Prog_Expr.lhs (1 * x ^^^ 2 = 0) = 1 * x ^^^ 2" : string
   249 > term2str t';
   250 val it = "Prog_Expr.lhs (1 * x ^^^ 2 = 0) = 1 * x ^^^ 2" : string
   251 *)
   252 
   253 fun rhs (Const ("HOL.eq",_) $ _ $ r) = r
   254   | rhs t = error("rhs called with (" ^ Rule.term2str t ^ ")");
   255 (*("rhs"    ,("Prog_Expr.rhs"    , eval_rhs "")):calc*)
   256 fun eval_rhs _ "Prog_Expr.rhs"
   257 	     (t as (Const ("Prog_Expr.rhs",_) $ (Const ("HOL.eq",_) $ _ $ r))) _ = 
   258     SOME (Rule.term2str t ^ " = " ^ Rule.term2str r,
   259 	  HOLogic.Trueprop $ (TermC.mk_equality (t, r)))
   260   | eval_rhs _ _ _ _ = NONE;
   261 (*\\------------------------- from Prog_Expr.thy-------------------------------------------------//*)
   262 
   263 (*//------------------------- from Atools.thy------------------------------------------------\\*)
   264 fun occurs_in v t = member op = (((map strip_thy) o TermC.ids2str) t) (Term.term_name v);
   265 
   266 (*("occurs_in", ("Prog_Expr.occurs'_in", Prog_Expr.eval_occurs_in ""))*)
   267 fun eval_occurs_in _ "Prog_Expr.occurs'_in"
   268 	     (p as (Const ("Prog_Expr.occurs'_in",_) $ v $ t)) _ =
   269     ((*tracing("@@@ eval_occurs_in: v= "^(Rule.term2str v));
   270      tracing("@@@ eval_occurs_in: t= "^(Rule.term2str t));*)
   271      if occurs_in v t
   272     then SOME ((Rule.term2str p) ^ " = True",
   273 	  HOLogic.Trueprop $ (TermC.mk_equality (p, @{term True})))
   274     else SOME ((Rule.term2str p) ^ " = False",
   275 	  HOLogic.Trueprop $ (TermC.mk_equality (p, @{term False}))))
   276   | eval_occurs_in _ _ _ _ = NONE;
   277 
   278 (*some of the (bound) variables (eg. in an eqsys) "vs" occur in term "t"*)   
   279 fun some_occur_in vs t = 
   280     let fun occurs_in' a b = occurs_in b a
   281     in foldl or_ (false, map (occurs_in' t) vs) end;
   282 
   283 (*("some_occur_in", ("Prog_Expr.some'_occur'_in", 
   284 			eval_some_occur_in "#eval_some_occur_in_"))*)
   285 fun eval_some_occur_in _ "Prog_Expr.some'_occur'_in"
   286 			  (p as (Const ("Prog_Expr.some'_occur'_in",_) 
   287 				       $ vs $ t)) _ =
   288     if some_occur_in (TermC.isalist2list vs) t
   289     then SOME ((Rule.term2str p) ^ " = True",
   290 	       HOLogic.Trueprop $ (TermC.mk_equality (p, @{term True})))
   291     else SOME ((Rule.term2str p) ^ " = False",
   292 	       HOLogic.Trueprop $ (TermC.mk_equality (p, @{term False})))
   293   | eval_some_occur_in _ _ _ _ = NONE;
   294 
   295 (*("is_atom",("Prog_Expr.is'_atom", Prog_Expr.eval_is_atom "#is_atom_"))*)
   296 fun eval_is_atom (thmid:string) "Prog_Expr.is'_atom"
   297 		 (t as (Const _ $ arg)) _ = 
   298     (case arg of 
   299 	 Free (n,_) => SOME (TermC.mk_thmid thmid n "", 
   300 			      HOLogic.Trueprop $ (TermC.mk_equality (t, @{term True})))
   301        | _ => SOME (TermC.mk_thmid thmid "" "", 
   302 		    HOLogic.Trueprop $ (TermC.mk_equality (t, @{term False}))))
   303   | eval_is_atom _ _ _ _ = NONE;
   304 
   305 fun even i = (i div 2) * 2 = i;
   306 (*("is_even",("Prog_Expr.is'_even", eval_is_even "#is_even_"))*)
   307 fun eval_is_even (thmid:string) "Prog_Expr.is'_even"
   308 		 (t as (Const _ $ arg)) _ = 
   309     (case arg of 
   310 	Free (n,_) =>
   311 	 (case TermC.int_of_str_opt n of
   312 	      SOME i =>
   313 	      if even i then SOME (TermC.mk_thmid thmid n "", 
   314 				   HOLogic.Trueprop $ (TermC.mk_equality (t, @{term True})))
   315 	      else SOME (TermC.mk_thmid thmid "" "", 
   316 			 HOLogic.Trueprop $ (TermC.mk_equality (t, @{term False})))
   317 	    | _ => NONE)
   318        | _ => NONE)
   319   | eval_is_even _ _ _ _ = NONE; 
   320 
   321 (*evaluate 'is_const'*)
   322 (*("is_const",("Prog_Expr.is'_const", Prog_Expr.eval_const "#is_const_"))*)
   323 fun eval_const (thmid:string) _ (t as (Const _ $ arg)) _ = 
   324     (case arg of 
   325        Const (n1, _) =>
   326 	     SOME (TermC.mk_thmid thmid n1 "", HOLogic.Trueprop $ (TermC.mk_equality (t, @{term False})))
   327      | Free (n1, _) =>
   328 	     if TermC.is_num' n1
   329 	     then SOME (TermC.mk_thmid thmid n1 "", HOLogic.Trueprop $ (TermC.mk_equality (t, @{term True})))
   330 	     else SOME (TermC.mk_thmid thmid n1 "", HOLogic.Trueprop $ (TermC.mk_equality (t, @{term False})))
   331      | _ => (*NONE*)
   332        SOME (TermC.mk_thmid thmid (Rule.term2str arg) "", HOLogic.Trueprop $ (TermC.mk_equality (t, @{term False}))))
   333   | eval_const _ _ _ _ = NONE; 
   334 
   335 (*. evaluate binary, associative, commutative operators: *,+,^ .*)
   336 (*("PLUS"    ,("Groups.plus_class.plus"        , (**)eval_binop "#add_")),
   337   ("TIMES"   ,("Groups.times_class.times"        , (**)eval_binop "#mult_")),
   338   ("POWER"  ,("Prog_Expr.pow"  , (**)eval_binop "#power_"))*)
   339 
   340 (* val (thmid,op_,t as(Const (op0,t0) $ Free (n1,t1) $ Free(n2,t2)),thy) =
   341        ("xxxxxx",op_,t,thy);
   342    *)
   343 fun mk_thmid_f thmid ((v11, v12), (p11, p12)) ((v21, v22), (p21, p22)) = (* dropped *)
   344   thmid ^ "Float ((" ^ 
   345   (string_of_int v11)^","^(string_of_int v12)^"), ("^
   346   (string_of_int p11)^","^(string_of_int p12)^")) __ (("^
   347   (string_of_int v21)^","^(string_of_int v22)^"), ("^
   348   (string_of_int p21)^","^(string_of_int p22)^"))";
   349 
   350 (*.evaluate < and <= for numerals.*)
   351 (*("le"      ,("Orderings.ord_class.less"        , Prog_Expr.eval_equ "#less_")),
   352   ("leq"     ,("Orderings.ord_class.less_eq"       , Prog_Expr.eval_equ "#less_equal_"))*)
   353 fun eval_equ (thmid:string) (_(*op_*)) (t as 
   354 	       (Const (op0, _) $ Free (n1, _) $ Free(n2, _))) _ = 
   355     (case (TermC.int_of_str_opt n1, TermC.int_of_str_opt n2) of
   356 	 (SOME n1', SOME n2') =>
   357   if Calc.calc_equ (strip_thy op0) (n1', n2')
   358     then SOME (TermC.mk_thmid thmid n1 n2, 
   359 	  HOLogic.Trueprop $ (TermC.mk_equality (t, @{term True})))
   360   else SOME (TermC.mk_thmid thmid n1 n2,  
   361 	  HOLogic.Trueprop $ (TermC.mk_equality (t, @{term False})))
   362        | _ => NONE)
   363     
   364   | eval_equ _ _ _ _ = NONE;
   365 
   366 
   367 (*evaluate identity
   368 > reflI;
   369 val it = "(?t = ?t) = True"
   370 > val t = str2term "x = 0";
   371 > val NONE = rewrite_ thy Rule.dummy_ord Rule.e_rls false reflI t;
   372 
   373 > val t = str2term "1 = 0";
   374 > val NONE = rewrite_ thy Rule.dummy_ord Rule.e_rls false reflI t;
   375 ----------- thus needs Rule.Calc !
   376 > val t = str2term "0 = 0";
   377 > val SOME (t',_) = rewrite_ thy Rule.dummy_ord Rule.e_rls false reflI t;
   378 > Rule.term2str t';
   379 val it = "HOL.True"
   380 
   381 val t = str2term "Not (x = 0)";
   382 atomt t; Rule.term2str t;
   383 *** -------------
   384 *** Const ( Not)
   385 *** . Const ( op =)
   386 *** . . Free ( x, )
   387 *** . . Free ( 0, )
   388 val it = "x ~= 0" : string*)
   389 
   390 (*.evaluate identity on the term-level, =!= ,i.e. without evaluation of 
   391   the arguments: thus special handling by 'fun eval_binop'*)
   392 (*("ident"   ,("Prog_Expr.ident", Prog_Expr.eval_ident "#ident_")):calc*)
   393 fun eval_ident (thmid:string) "Prog_Expr.ident" (t as 
   394 	       (Const _(*op0, t0*) $ t1 $ t2 )) thy = 
   395   if t1 = t2
   396   then SOME (TermC.mk_thmid thmid 
   397 	              ("(" ^ (Rule.term_to_string''' thy t1) ^ ")")
   398 	              ("(" ^ (Rule.term_to_string''' thy t2) ^ ")"), 
   399 	     HOLogic.Trueprop $ (TermC.mk_equality (t, @{term True})))
   400   else SOME (TermC.mk_thmid thmid  
   401 	              ("(" ^ (Rule.term_to_string''' thy t1) ^ ")")
   402 	              ("(" ^ (Rule.term_to_string''' thy t2) ^ ")"),  
   403 	     HOLogic.Trueprop $ (TermC.mk_equality (t, @{term False})))
   404   | eval_ident _ _ _ _ = NONE;
   405 (* TODO
   406 > val t = str2term "x =!= 0";
   407 > val SOME (str, t') = eval_ident "ident_" "b" t thy;
   408 > Rule.term2str t';
   409 val str = "ident_(x)_(0)" : string
   410 val it = "(x =!= 0) = False" : string                                
   411 > val t = str2term "1 =!= 0";
   412 > val SOME (str, t') = eval_ident "ident_" "b" t thy;
   413 > Rule.term2str t';
   414 val str = "ident_(1)_(0)" : string 
   415 val it = "(1 =!= 0) = False" : string                                       
   416 > val t = str2term "0 =!= 0";
   417 > val SOME (str, t') = eval_ident "ident_" "b" t thy;
   418 > Rule.term2str t';
   419 val str = "ident_(0)_(0)" : string
   420 val it = "(0 =!= 0) = True" : string
   421 *)
   422 
   423 (*.evaluate identity of terms, which stay ready for evaluation in turn;
   424   thus returns False only for atoms.*)
   425 (*("equal"   ,("HOL.eq", Prog_Expr.eval_equal "#equal_")):calc*)
   426 fun eval_equal (thmid : string) "HOL.eq" (t as (Const _(*op0,t0*) $ t1 $ t2 )) thy = 
   427   if t1 = t2
   428   then SOME (TermC.mk_thmid thmid 
   429                 ("(" ^ Rule.term_to_string''' thy t1 ^ ")")
   430                 ("(" ^ Rule.term_to_string''' thy t2 ^ ")"), 
   431        HOLogic.Trueprop $ (TermC.mk_equality (t, @{term True})))
   432   else (case (TermC.is_atom t1, TermC.is_atom t2) of
   433       (true, true) => 
   434       SOME (TermC.mk_thmid thmid  
   435          ("(" ^ Rule.term_to_string''' thy t1 ^ ")")
   436          ("(" ^ Rule.term_to_string''' thy t2 ^ ")"),
   437       HOLogic.Trueprop $ (TermC.mk_equality (t, @{term False})))
   438     | _ => NONE)                             (* NOT is_atom t1,t2 --> rew_sub *)
   439   | eval_equal _ _ _ _ = NONE;                                  (* error-exit *)
   440 (*
   441 val t = str2term "x ~= 0";
   442 val NONE = eval_equal "equal_" "b" t thy;
   443 
   444 
   445 > val t = str2term "(x + 1) = (x + 1)";
   446 > val SOME (str, t') = eval_equal "equal_" "b" t thy;
   447 > Rule.term2str t';
   448 val str = "equal_(x + 1)_(x + 1)" : string
   449 val it = "(x + 1 = x + 1) = True" : string
   450 > val t = str2term "x = 0";
   451 > val NONE = eval_equal "equal_" "b" t thy;
   452 
   453 > val t = str2term "1 = 0";
   454 > val SOME (str, t') = eval_equal "equal_" "b" t thy;
   455 > Rule.term2str t';
   456 val str = "equal_(1)_(0)" : string 
   457 val it = "(1 = 0) = False" : string
   458 > val t = str2term "0 = 0";
   459 > val SOME (str, t') = eval_equal "equal_" "b" t thy;
   460 > Rule.term2str t';
   461 val str = "equal_(0)_(0)" : string
   462 val it = "(0 = 0) = True" : string
   463 *)
   464 
   465 (*. evaluate HOL.divide .*)
   466 (*("DIVIDE" ,("Rings.divide_class.divide"  , eval_cancel "#divide_e"))*)
   467 fun eval_cancel (thmid: string) "Rings.divide_class.divide" (t as 
   468 	       (Const (op0,t0) $ Free (n1, _) $ Free(n2, _))) _ = 
   469     (case (TermC.int_of_str_opt n1, TermC.int_of_str_opt n2) of
   470     	(SOME n1', SOME n2') =>
   471         let 
   472           val sg = Calc.sign_mult n1' n2';
   473           val (T1,T2,Trange) = TermC.dest_binop_typ t0;
   474           val gcd' = Calc.gcd (abs n1') (abs n2');
   475         in if gcd' = abs n2' 
   476            then let val rhs = TermC.term_of_num Trange (sg * (abs n1') div gcd')
   477     	        val prop = HOLogic.Trueprop $ (TermC.mk_equality (t, rhs))
   478     	    in SOME (TermC.mk_thmid thmid n1 n2, prop) end     
   479            else if 0 < n2' andalso gcd' = 1 then NONE
   480            else let val rhs = TermC.mk_num_op_num T1 T2 (op0,t0) (sg * (abs n1') div gcd')
   481     	  			   ((abs n2') div gcd')
   482     	        val prop = HOLogic.Trueprop $ (TermC.mk_equality (t, rhs))
   483     	    in SOME (TermC.mk_thmid thmid n1 n2, prop) end
   484         end
   485       | _ => ((*tracing"@@@ eval_cancel NONE";*)NONE))
   486   | eval_cancel _ _ _ _ = NONE;
   487 
   488 (* get the argument from a function-definition *)
   489 (*("argument_in" ,("Prog_Expr.argument'_in", Prog_Expr.eval_argument_in "Prog_Expr.argument'_in"))*)
   490 fun eval_argument_in _ "Prog_Expr.argument'_in" 
   491 		 (t as (Const ("Prog_Expr.argument'_in", _) $ (_(*f*) $ arg))) _ =
   492     if is_Free arg (*could be something to be simplified before*)
   493     then
   494       SOME (Rule.term2str t ^ " = " ^ Rule.term2str arg,
   495 	      HOLogic.Trueprop $ (TermC.mk_equality (t, arg)))
   496     else NONE
   497   | eval_argument_in _ _ _ _ = NONE;
   498 
   499 (* check if the function-identifier of the first argument matches 
   500    the function-identifier of the lhs of the second argument *)
   501 (*("sameFunId" ,("Prog_Expr.sameFunId", eval_same_funid "Prog_Expr.sameFunId"))*)
   502 fun eval_sameFunId _ "Prog_Expr.sameFunId" 
   503 		     (p as Const ("Prog_Expr.sameFunId",_) $  (f1 $ _) $ (Const ("HOL.eq", _) $ (f2 $ _) $ _)) _ =
   504     if f1 = f2 
   505     then SOME ((Rule.term2str p) ^ " = True",
   506 	       HOLogic.Trueprop $ (TermC.mk_equality (p, @{term True})))
   507     else SOME ((Rule.term2str p) ^ " = False",
   508 	       HOLogic.Trueprop $ (TermC.mk_equality (p, @{term False})))
   509 | eval_sameFunId _ _ _ _ = NONE;
   510 
   511 
   512 (*.from a list of fun-definitions "f x = ..." as 2nd argument
   513    filter the elements with the same fun-identfier in "f y"
   514    as the fst argument;
   515    this is, because Isabelles filter takes more than 1 sec.*)
   516 fun same_funid f1 (Const ("HOL.eq", _) $ (f2 $ _) $ _) = f1 = f2
   517   | same_funid f1 t = error ("same_funid called with t = ("
   518 				   ^Rule.term2str f1^") ("^Rule.term2str t^")");
   519 (*("filter_sameFunId" ,("Prog_Expr.filter'_sameFunId",
   520 		   eval_filter_sameFunId "Prog_Expr.filter'_sameFunId"))*)
   521 fun eval_filter_sameFunId _ "Prog_Expr.filter'_sameFunId" 
   522 		     (p as Const ("Prog_Expr.filter'_sameFunId",_) $ 
   523 			(fid $ _) $ fs) _ =
   524     let val fs' = ((TermC.list2isalist HOLogic.boolT) o 
   525 		   (filter (same_funid fid))) (TermC.isalist2list fs)
   526     in SOME (Rule.term2str (TermC.mk_equality (p, fs')),
   527 	       HOLogic.Trueprop $ (TermC.mk_equality (p, fs'))) end
   528 | eval_filter_sameFunId _ _ _ _ = NONE;
   529 
   530 (* make a list of terms to a sum *)
   531 fun list2sum [] = error ("list2sum called with []")
   532   | list2sum [s] = s
   533   | list2sum (s::ss) = 
   534     let
   535       fun sum su [s'] = Const ("Groups.plus_class.plus",
   536            [HOLogic.realT,HOLogic.realT] ---> HOLogic.realT) $ su $ s'
   537     	  | sum su (s'::ss') = sum (Const ("Groups.plus_class.plus",
   538            [HOLogic.realT,HOLogic.realT] ---> HOLogic.realT) $ su $ s') ss'
   539     	  | sum _ _ = raise ERROR "list2sum: pattern in fun.def is missing" 
   540     in sum s ss end;
   541 
   542 (* make a list of equalities to the sum of the lhs *)
   543 (*("boollist2sum"    ,("Prog_Expr.boollist2sum"    , eval_boollist2sum "")):calc*)
   544 fun eval_boollist2sum _ "Prog_Expr.boollist2sum" 
   545 		  (p as Const ("Prog_Expr.boollist2sum", _) $ (l as Const ("List.list.Cons", _) $ _ $ _)) _ =
   546     let
   547       val isal = TermC.isalist2list l
   548 	    val lhss = map lhs isal
   549 	    val sum = list2sum lhss
   550     in
   551       SOME ((Rule.term2str p) ^ " = " ^ (Rule.term2str sum),
   552 	      HOLogic.Trueprop $ (TermC.mk_equality (p, sum)))
   553     end
   554   | eval_boollist2sum _ _ _ _ = NONE;
   555 
   556 (**) end (*struct*)
   557 \<close> text \<open>
   558 open Prog_Expr
   559 \<close> ML \<open>
   560 \<close> ML \<open>
   561 \<close>
   562 
   563 subsection \<open>extend rule-set for evaluating pre-conditions and program-expressions\<close>
   564 ML \<open>
   565 val list_rls = Rule.append_rls "list_rls" list_rls [Rule.Calc ("Prog_Expr.rhs", Prog_Expr.eval_rhs "")];
   566 \<close> ML \<open>
   567 \<close> ML \<open>
   568 \<close>
   569 
   570 subsection \<open>setup for rule-sets and ML-functions\<close>
   571 setup \<open>KEStore_Elems.add_rlss [("list_rls", (Context.theory_name @{theory}, list_rls))]\<close>
   572 setup \<open>KEStore_Elems.add_calcs
   573   [("matches", ("Prog_Expr.matches", Prog_Expr.eval_matches "#matches_")),
   574     ("matchsub", ("Prog_Expr.matchsub", Prog_Expr.eval_matchsub "#matchsub_")),
   575     ("Vars", ("Prog_Expr.Vars", Prog_Expr.eval_var "#Vars_")),
   576     ("lhs", ("Prog_Expr.lhs", Prog_Expr.eval_lhs "")),
   577     ("rhs", ("Prog_Expr.rhs", Prog_Expr.eval_rhs ""))]\<close>
   578 (*\\------------------------- from Tools .thy-------------------------------------------------//*)
   579 ML \<open>
   580 \<close> ML \<open>
   581 \<close> ML \<open>
   582 \<close>
   583 
   584 end