src/Tools/isac/ProgLang/Prog_Expr.thy
author wneuper <walther.neuper@jku.at>
Wed, 18 Aug 2021 16:03:08 +0200
changeset 60385 d3a3cc2f0382
parent 60343 f6e98785473f
child 60386 b7ea87559ad5
permissions -rw-r--r--
\\replace is_const with is_num: STRANGE ERROR assoc_calc: 'Prog_Expr.is_num' not found in theory Poly
     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_atom         :: "real => bool"            ("_ is'_atom" 10)
    35   is_num         :: "real => bool"             ("_ is'_num" 10)
    36   is_even         :: "real => bool"            ("_ is'_even" 10)
    37 		
    38   (* identity on term level*)
    39   ident            :: "['a, 'a] => bool"        ("(_ =!=/ _)" [51, 51] 50)
    40   argument_in     :: "real => real"            ("argument'_in _" 10)
    41   sameFunId        :: "[real, bool] => bool"    (* "same_funid _ _" 10
    42 	                    WN0609 changed the id, because ".. _ _" inhibits currying *)
    43   filter_sameFunId:: "[real, bool list] => bool list" ("filter'_sameFunId _ _" 10)
    44   boollist2sum     :: "bool list => real"
    45   lastI            :: "'a list \<Rightarrow> 'a"
    46 
    47 subsection \<open>ML code for functions in pre-conditions and program-expressions\<close>
    48 ML \<open>
    49 signature PROG_EXPR =
    50   sig
    51 (*//------------------------- from Tools .thy-------------------------------------------------\\*)
    52     val lhs: term -> term
    53     val eval_lhs: 'a -> string -> term -> 'b -> (string * term) option
    54     val eval_matches: string -> string -> term -> theory -> (string * term) option
    55     val matchsub: theory -> term -> term -> bool
    56     val eval_matchsub: string -> string -> term -> theory -> (string * term) option
    57     val rhs: term -> term
    58     val eval_rhs: 'a -> string -> term -> 'b -> (string * term) option
    59     val eval_var: string -> string -> term -> theory -> (string * term) option
    60 
    61     val or2list: term -> term
    62 (*\\------------------------- from Tools .thy-------------------------------------------------//*)
    63 (*//------------------------- from Atools .thy------------------------------------------------\\*)
    64     val occurs_in: term -> term -> bool
    65     val eval_occurs_in: 'a -> string -> term -> 'b -> (string * term) option
    66     val some_occur_in: term list -> term -> bool
    67     val eval_some_occur_in: 'a -> string -> term -> 'b -> (string * term) option
    68     val eval_is_atom: string -> string -> term -> 'a -> (string * term) option
    69     val eval_is_num: string -> string -> term -> 'a -> (string * term) option
    70     val even: int -> bool
    71     val eval_is_even: string -> string -> term -> 'a -> (string * term) option
    72     val eval_const: string -> string -> term -> 'a -> (string * term) option
    73     val eval_equ: string -> string -> term -> 'a -> (string * term) option
    74     val eval_ident: string -> string -> term -> theory -> (string * term) option
    75     val eval_equal: string -> string -> term -> theory -> (string * term) option
    76     val eval_cancel: string -> string -> term -> 'a -> (string * term) option
    77     val eval_argument_in: string -> string -> term -> 'a -> (string * term) option
    78     val same_funid: term -> term -> bool
    79     val eval_sameFunId: string -> string -> term -> 'a -> (string * term) option
    80     val eval_filter_sameFunId: string -> string -> term -> 'a -> (string * term) option
    81     val list2sum: term list -> term
    82     val eval_boollist2sum: string -> string -> term -> 'a -> (string * term) option
    83 
    84     val mk_thmid_f: string -> (int * int) * (int * int) -> (int * int) * (int * int) -> string
    85   end
    86 
    87 (**)
    88 structure Prog_Expr(**): PROG_EXPR =(**)
    89 struct
    90 (**)
    91 
    92 (*+ for Or_to_List +*)
    93 fun or2list (Const (\<^const_name>\<open>True\<close>,_)) = ((*tracing"### or2list True";*) UniversalList)
    94   | or2list (Const (\<^const_name>\<open>False\<close>,_)) = ((*tracing"### or2list False";*) EmptyList)
    95   | or2list (t as Const (\<^const_name>\<open>HOL.eq\<close>,_) $ _ $ _) = TermC.list2isalist HOLogic.boolT [t]
    96   | or2list ors =
    97     let
    98       fun get ls (Const (\<^const_name>\<open>disj\<close>,_) $ o1 $ o2) =
    99 	        (case o2 of
   100 	         	Const (\<^const_name>\<open>disj\<close>,_) $ _ $ _ => get (ls @ [o1]) o2
   101 	        | _ => ls @ [o1, o2])
   102         | get _ t = raise TERM ("or2list: missing pattern in fun.def", [t])
   103     in (((TermC.list2isalist HOLogic.boolT) o (get [])) ors) end
   104 (*>val t = @{term True};
   105 > val t' = or2list t;
   106 > term2str t';
   107 "ListC.UniversalList"
   108 > val t = @{term False};
   109 > val t' = or2list t;
   110 > term2str t';
   111 "[]"
   112 > val t=(Thm.term_of o the o (parse thy)) "x=3";
   113 > val t' = or2list t;
   114 > term2str t';
   115 "[x = 3]"
   116 > val t=(Thm.term_of o the o (parse thy))"(x=3) | (x=-3) | (x=0)";
   117 > val t' = or2list t;
   118 > term2str t';
   119 "[x = #3, x = #-3, x = #0]" : string *)
   120 
   121 
   122 (** evaluation on the meta-level **)
   123 
   124 (*. evaluate the predicate matches (match on whole term only) .*)
   125 (*("matches",("Prog_Expr.matches", eval_matches "#matches_")):calc*)
   126 fun eval_matches (_:string) "Prog_Expr.matches" (t as Const (\<^const_name>\<open>Prog_Expr.matches\<close>, _) $ pat $ tst) thy = 
   127     if TermC.matches thy tst pat
   128     then 
   129       let
   130         val prop = HOLogic.Trueprop $ (TermC.mk_equality (t, @{term True}))
   131 	    in SOME (UnparseC.term_in_thy thy prop, prop) end
   132     else 
   133       let 
   134         val prop = HOLogic.Trueprop $ (TermC.mk_equality (t, @{term False}))
   135 	    in SOME (UnparseC.term_in_thy thy prop, prop) end
   136   | eval_matches _ _ _ _ = NONE; 
   137 (*
   138 > val t  = (Thm.term_of o the o (parse thy)) 
   139 	      "matches (?x = 0) (1 * x \<up> 2 = 0)";
   140 > eval_matches "/thmid/" "/op_/" t thy;
   141 val it =
   142   SOME
   143     ("matches (x = 0) (1 * x \<up> 2 = 0) = False",
   144      Const (#,#) $ (# $ # $ Const #)) : (string * term) option
   145 
   146 > val t  = (Thm.term_of o the o (parse thy)) 
   147 	      "matches (?a = #0) (#1 * x \<up> #2 = #0)";
   148 > eval_matches "/thmid/" "/op_/" t thy;
   149 val it =
   150   SOME
   151     ("matches (?a = #0) (#1 * x \<up> #2 = #0) = True",
   152      Const (#,#) $ (# $ # $ Const #)) : (string * term) option
   153 
   154 > val t  = (Thm.term_of o the o (parse thy)) 
   155 	      "matches (?a * x = #0) (#1 * x \<up> #2 = #0)";
   156 > eval_matches "/thmid/" "/op_/" t thy;
   157 val it =
   158   SOME
   159     ("matches (?a * x = #0) (#1 * x \<up> #2 = #0) = False",
   160      Const (#,#) $ (# $ # $ Const #)) : (string * term) option
   161 
   162 > val t  = (Thm.term_of o the o (parse thy)) 
   163 	      "matches (?a * x \<up> #2 = #0) (#1 * x \<up> #2 = #0)";
   164 > eval_matches "/thmid/" "/op_/" t thy;
   165 val it =
   166   SOME
   167     ("matches (?a * x \<up> #2 = #0) (#1 * x \<up> #2 = #0) = True",
   168      Const (#,#) $ (# $ # $ Const #)) : (string * term) option                  
   169 ----- before ?patterns ---:
   170 > val t  = (Thm.term_of o the o (parse thy)) 
   171 	      "matches (a * b \<up> #2 = c) (#3 * x \<up> #2 = #1)";
   172 > eval_matches "/thmid/" "/op_/" t thy;
   173 SOME
   174     ("matches (a * b \<up> #2 = c) (#3 * x \<up> #2 = #1) = True",
   175      Const ("HOL.Trueprop", "bool => prop") $ (Const # $ (# $ #) $ Const (#,#)))
   176   : (string * term) option 
   177 
   178 > val t = (Thm.term_of o the o (parse thy)) 
   179 	      "matches (a * b \<up> #2 = c) (#3 * x \<up> #2222 = #1)";
   180 > eval_matches "/thmid/" "/op_/" t thy;
   181 SOME ("matches (a * b \<up> #2 = c) (#3 * x \<up> #2222 = #1) = False",
   182      Const ("HOL.Trueprop", "bool => prop") $ (Const # $ (# $ #) $ Const (#,#)))
   183 
   184 > val t = (Thm.term_of o the o (parse thy)) 
   185                "matches (a = b) (x + #1 + #-1 * #2 = #0)";
   186 > eval_matches "/thmid/" "/op_/" t thy;
   187 SOME ("matches (a = b) (x + #1 + #-1 * #2 = #0) = True",Const # $ (# $ #))
   188 *)
   189 
   190 (*.does a pattern match some subterm ?.*)
   191 fun matchsub thy t pat =  
   192   let
   193     fun matchs (t as Const _) = TermC.matches thy t pat
   194 	      | matchs (t as Free _) = TermC.matches thy t pat
   195 	      | matchs (t as Var _) = TermC.matches thy t pat
   196 	      | matchs (Bound _) = false
   197 	      | matchs (t as Abs (_, _, body)) = 
   198 	          if TermC.matches thy t pat then true else TermC.matches thy body pat
   199 	      | matchs (t as f1 $ f2) =
   200 	          if TermC.matches thy t pat then true 
   201 	            else if matchs f1 then true else matchs f2
   202   in matchs t end;
   203 
   204 (*("matchsub",("Prog_Expr.matchsub", eval_matchsub "#matchsub_")):calc*)
   205 fun eval_matchsub (_:string) "Prog_Expr.matchsub"
   206       (t as Const (\<^const_name>\<open>Prog_Expr.matchsub\<close>, _) $ pat $ tst) thy = 
   207     if matchsub thy tst pat
   208     then 
   209       let val prop = HOLogic.Trueprop $ (TermC.mk_equality (t, @{term True}))
   210       in SOME (UnparseC.term_in_thy thy prop, prop) end
   211     else 
   212       let val prop = HOLogic.Trueprop $ (TermC.mk_equality (t, @{term False}))
   213       in SOME (UnparseC.term_in_thy thy prop, prop) end
   214   | eval_matchsub _ _ _ _ = NONE; 
   215 
   216 (*get the variables in an isabelle-term*)
   217 (*("Vars"    ,("Prog_Expr.Vars"    , eval_var "#Vars_")):calc*)
   218 fun eval_var (thmid:string) "Prog_Expr.Vars" (t as (Const _ $ arg)) thy = 
   219     let 
   220       val t' = ((TermC.list2isalist HOLogic.realT) o TermC.vars) t;
   221       val thmId = thmid ^ UnparseC.term_in_thy thy arg;
   222     in SOME (thmId, HOLogic.Trueprop $ (TermC.mk_equality (t, t'))) end
   223   | eval_var _ _ _ _ = NONE;
   224 
   225 (* refer to Thm.lhs_of *)
   226 fun lhs (Const (\<^const_name>\<open>HOL.eq\<close>,_) $ l $ _) = l
   227   | lhs t = raise ERROR("lhs called with (" ^ UnparseC.term t ^ ")");
   228 (*("lhs"    ,("Prog_Expr.lhs"    , eval_lhs "")):calc*)
   229 fun eval_lhs _ "Prog_Expr.lhs" (t as (Const (\<^const_name>\<open>lhs\<close>,_) $ (Const (\<^const_name>\<open>HOL.eq\<close>,_) $ l $ _))) _ = 
   230     SOME ((UnparseC.term t) ^ " = " ^ (UnparseC.term l),
   231 	  HOLogic.Trueprop $ (TermC.mk_equality (t, l)))
   232   | eval_lhs _ _ _ _ = NONE;
   233 (*
   234 > val t = (Thm.term_of o the o (parse thy)) "lhs (1 * x \<up> 2 = 0)";
   235 > val SOME (id,t') = eval_lhs 0 0 t 0;
   236 val id = "Prog_Expr.lhs (1 * x \<up> 2 = 0) = 1 * x \<up> 2" : string
   237 > term2str t';
   238 val it = "Prog_Expr.lhs (1 * x \<up> 2 = 0) = 1 * x \<up> 2" : string
   239 *)
   240 
   241 fun rhs (Const (\<^const_name>\<open>HOL.eq\<close>,_) $ _ $ r) = r
   242   | rhs t = raise ERROR("rhs called with (" ^ UnparseC.term t ^ ")");
   243 (*("rhs"    ,("Prog_Expr.rhs"    , eval_rhs "")):calc*)
   244 fun eval_rhs _ "Prog_Expr.rhs" (t as (Const (\<^const_name>\<open>rhs\<close>,_) $ (Const (\<^const_name>\<open>HOL.eq\<close>,_) $ _ $ r))) _ = 
   245     SOME (UnparseC.term t ^ " = " ^ UnparseC.term r,
   246 	  HOLogic.Trueprop $ (TermC.mk_equality (t, r)))
   247   | eval_rhs _ _ _ _ = NONE;
   248 (*\\------------------------- from Prog_Expr.thy-------------------------------------------------//*)
   249 
   250 (*//------------------------- from Atools.thy------------------------------------------------\\*)
   251 fun occurs_in v t = member op = (((map strip_thy) o TermC.ids2str) t) (Term.term_name v);
   252 
   253 (*("occurs_in", ("Prog_Expr.occurs_in", Prog_Expr.eval_occurs_in ""))*)
   254 fun eval_occurs_in _ "Prog_Expr.occurs_in" (p as (Const (\<^const_name>\<open>occurs_in\<close>, _) $ v $ t)) _ =
   255     ((*tracing("#>@ eval_occurs_in: v= "^(UnparseC.term v));
   256      tracing("#>@ eval_occurs_in: t= "^(UnparseC.term t));*)
   257      if occurs_in v t
   258     then SOME ((UnparseC.term p) ^ " = True",
   259 	  HOLogic.Trueprop $ (TermC.mk_equality (p, @{term True})))
   260     else SOME ((UnparseC.term p) ^ " = False",
   261 	  HOLogic.Trueprop $ (TermC.mk_equality (p, @{term False}))))
   262   | eval_occurs_in _ _ _ _ = NONE;
   263 
   264 (*some of the (bound) variables (eg. in an eqsys) "vs" occur in term "t"*)   
   265 fun some_occur_in vs t = 
   266     let fun occurs_in' a b = occurs_in b a
   267     in foldl or_ (false, map (occurs_in' t) vs) end;
   268 
   269 (*("some_occur_in", ("Prog_Expr.some_occur_in", 
   270 			eval_some_occur_in "#eval_some_occur_in_"))*)
   271 fun eval_some_occur_in _ "Prog_Expr.some_occur_in"
   272 			  (p as (Const (\<^const_name>\<open>some_occur_in\<close>,_) $ vs $ t)) _ =
   273     if some_occur_in (TermC.isalist2list vs) t
   274     then SOME ((UnparseC.term p) ^ " = True",
   275 	       HOLogic.Trueprop $ (TermC.mk_equality (p, @{term True})))
   276     else SOME ((UnparseC.term p) ^ " = False",
   277 	       HOLogic.Trueprop $ (TermC.mk_equality (p, @{term False})))
   278   | eval_some_occur_in _ _ _ _ = NONE;
   279 
   280 (*("is_atom",("Prog_Expr.is_atom", Prog_Expr.eval_is_atom "#is_atom_"))*)
   281 fun eval_is_atom (thmid:string) "Prog_Expr.is_atom" (t as (Const _ $ arg)) _ = 
   282     if TermC.is_atom arg
   283     then SOME (TermC.mk_thmid thmid (TermC.string_of_atom arg) "", 
   284 			HOLogic.Trueprop $ (TermC.mk_equality (t, @{term True})))
   285     else SOME (TermC.mk_thmid thmid (TermC.string_of_atom arg) "", 
   286 		  HOLogic.Trueprop $ (TermC.mk_equality (t, @{term False})))
   287   | eval_is_atom _ _ _ _ = NONE;
   288 
   289 (*("is_num",("Prog_Expr.is_num", Prog_Expr.eval_is_num "#is_num_"))*)
   290 fun eval_is_num (thmid:string) "Prog_Expr.is_num" (t as (Const _ $ arg)) _ = 
   291     if TermC.is_num arg
   292     then SOME (TermC.mk_thmid thmid (TermC.string_of_atom arg) "", 
   293 			HOLogic.Trueprop $ (TermC.mk_equality (t, @{term True})))
   294     else SOME (TermC.mk_thmid thmid (TermC.string_of_atom arg) "", 
   295 		  HOLogic.Trueprop $ (TermC.mk_equality (t, @{term False})))
   296   | eval_is_num _ _ _ _ = NONE;
   297 
   298 fun even i = (i div 2) * 2 = i;
   299 (*("is_even",("Prog_Expr.is_even", eval_is_even "#is_even_"))*)
   300 fun eval_is_even (thmid:string) "Prog_Expr.is_even" (t as (Const _ $ arg)) _ = 
   301     if TermC.is_num arg
   302     then
   303       let
   304         val i = arg |> HOLogic.dest_number |> snd
   305       in
   306 	      if even i 
   307         then SOME (TermC.mk_thmid thmid (string_of_int i) "", 
   308 				  HOLogic.Trueprop $ (TermC.mk_equality (t, @{term True})))
   309 	      else SOME (TermC.mk_thmid thmid "" "", 
   310 			    HOLogic.Trueprop $ (TermC.mk_equality (t, @{term False})))
   311       end
   312     else NONE
   313   | eval_is_even _ _ _ _ = NONE; 
   314 
   315 (*("is_num",("Prog_Expr.is_num", Prog_Expr.eval_is_num "#is_num_"))*)
   316 fun eval_const thmid _ (t as (Const (\<^const_name>\<open>is_num\<close>, _) $ Const ("Partial_Fractions.AA", _))) _ =
   317     (*TODO get rid of this special case*)
   318     SOME (TermC.mk_thmid thmid (UnparseC.term t) "",
   319       HOLogic.Trueprop $ (TermC.mk_equality (t, @{term False})))
   320   | eval_const thmid _ (t as (Const (\<^const_name>\<open>is_num\<close>, _) $ Const _)) _ =
   321     SOME (TermC.mk_thmid thmid (UnparseC.term t) "",
   322       HOLogic.Trueprop $ (TermC.mk_equality (t, @{term True})))
   323   | eval_const thmid _ (t as (Const (\<^const_name>\<open>is_num\<close>, _) $ n)) _ =
   324 	   if TermC.is_num n
   325 	   then SOME (TermC.mk_thmid thmid (TermC.string_of_num n) "",
   326        HOLogic.Trueprop $ (TermC.mk_equality (t, @{term True})))
   327 	   else SOME (TermC.mk_thmid thmid (UnparseC.term n) "",
   328        HOLogic.Trueprop $ (TermC.mk_equality (t, @{term False})))
   329   | eval_const _ _ _ _ = NONE; 
   330 
   331 (*. evaluate binary, associative, commutative operators: *,+,^ .*)
   332 (*("PLUS"    ,(\<^const_name>\<open>plus\<close>        , (**)eval_binop "#add_")),
   333   ("TIMES"   ,(\<^const_name>\<open>times\<close>        , (**)eval_binop "#mult_")),
   334   ("POWER"  ,(\<^const_name>\<open>powr\<close>  , (**)eval_binop "#power_"))*)
   335 
   336 (* val (thmid,op_,t as(Const (op0,t0) $ Free (n1,t1) $ Free(n2,t2)),thy) =
   337        ("xxxxxx",op_,t,thy);
   338    *)
   339 fun mk_thmid_f thmid ((v11, v12), (p11, p12)) ((v21, v22), (p21, p22)) = (* dropped *)
   340   thmid ^ "Float ((" ^ 
   341   (string_of_int v11)^", "^(string_of_int v12)^"), ("^
   342   (string_of_int p11)^", "^(string_of_int p12)^")) __ (("^
   343   (string_of_int v21)^", "^(string_of_int v22)^"), ("^
   344   (string_of_int p21)^", "^(string_of_int p22)^"))";
   345 
   346 (*.evaluate < and <= for numerals.*)
   347 (*("le"      ,(\<^const_name>\<open>less\<close>        , Prog_Expr.eval_equ "#less_")),
   348   ("leq"     ,(\<^const_name>\<open>less_eq\<close>       , Prog_Expr.eval_equ "#less_equal_"))*)
   349 
   350 fun eval_equ (thmid:string) (_(*op_*)) (t as (Const (op0, _)) $ t1 $ t2) _ =
   351     if TermC.is_num t1 andalso TermC.is_num t2 then
   352       let
   353         val n1 = t1 |> HOLogic.dest_number |> snd 
   354         val n2 = t2 |> HOLogic.dest_number |> snd 
   355       in
   356         if Eval.calc_equ (strip_thy op0) (n1, n2)
   357         then SOME (TermC.mk_thmid thmid (string_of_int n1) (string_of_int n2), 
   358     	    HOLogic.Trueprop $ (TermC.mk_equality (t, @{term True})))
   359         else SOME (TermC.mk_thmid thmid (string_of_int n1) (string_of_int n2),  
   360     	   HOLogic.Trueprop $ (TermC.mk_equality (t, @{term False})))
   361       end
   362     else NONE
   363   | eval_equ _ _ _ _ = NONE;
   364 
   365 
   366 (*evaluate identity
   367 > reflI;
   368 val it = "(?t = ?t) = True"
   369 > val t = str2term "x = 0";
   370 > val NONE = rewrite_ thy Rewrite_Ord.dummy_ord Rule_Set.empty false reflI t;
   371 
   372 > val t = str2term "1 = 0";
   373 > val NONE = rewrite_ thy Rewrite_Ord.dummy_ord Rule_Set.empty false reflI t;
   374 ----------- thus needs Rule.Eval !
   375 > val t = str2term "0 = 0";
   376 > val SOME (t',_) = rewrite_ thy Rewrite_Ord.dummy_ord Rule_Set.empty false reflI t;
   377 > UnparseC.term t';
   378 val it = \<^const_name>\<open>True\<close>
   379 
   380 val t = str2term "Not (x = 0)";
   381 atomt t; UnparseC.term t;
   382 *** -------------
   383 *** Const ( Not)
   384 *** . Const ( op =)
   385 *** . . Free ( x, )
   386 *** . . Free ( 0, )
   387 val it = "x ~= 0" : string*)
   388 
   389 (*.evaluate identity on the term-level, =!= ,i.e. without evaluation of 
   390   the arguments: thus special handling by 'fun eval_binop'*)
   391 (*("ident"   ,("Prog_Expr.ident", Prog_Expr.eval_ident "#ident_")):calc*)
   392 fun eval_ident (thmid:string) "Prog_Expr.ident" (t as 
   393 	       (Const _(*op0, t0*) $ t1 $ t2 )) thy = 
   394   if t1 = t2
   395   then SOME (TermC.mk_thmid thmid 
   396 	              ("(" ^ (UnparseC.term_in_thy thy t1) ^ ")")
   397 	              ("(" ^ (UnparseC.term_in_thy thy t2) ^ ")"), 
   398 	     HOLogic.Trueprop $ (TermC.mk_equality (t, @{term True})))
   399   else SOME (TermC.mk_thmid thmid  
   400 	              ("(" ^ (UnparseC.term_in_thy thy t1) ^ ")")
   401 	              ("(" ^ (UnparseC.term_in_thy thy t2) ^ ")"),  
   402 	     HOLogic.Trueprop $ (TermC.mk_equality (t, @{term False})))
   403   | eval_ident _ _ _ _ = NONE;
   404 (* TODO
   405 > val t = str2term "x =!= 0";
   406 > val SOME (str, t') = eval_ident "ident_" "b" t thy;
   407 > UnparseC.term t';
   408 val str = "ident_(x)_(0)" : string
   409 val it = "(x =!= 0) = False" : string                                
   410 > val t = str2term "1 =!= 0";
   411 > val SOME (str, t') = eval_ident "ident_" "b" t thy;
   412 > UnparseC.term t';
   413 val str = "ident_(1)_(0)" : string 
   414 val it = "(1 =!= 0) = False" : string                                       
   415 > val t = str2term "0 =!= 0";
   416 > val SOME (str, t') = eval_ident "ident_" "b" t thy;
   417 > UnparseC.term t';
   418 val str = "ident_(0)_(0)" : string
   419 val it = "(0 =!= 0) = True" : string
   420 *)
   421 
   422 
   423 (* evaluate identity of terms, which stay ready for further evaluation;
   424   thus returns False only for atoms *)
   425 (*("equal"   ,(\<^const_name>\<open>HOL.eq\<close>, Prog_Expr.eval_equal "#equal_")):calc*)
   426 fun eval_equal (thmid : string) \<^const_name>\<open>HOL.eq\<close> (t as (Const _(*op0,t0*) $ t1 $ t2 )) thy = 
   427   if t1 = t2
   428   then
   429     SOME (TermC.mk_thmid thmid
   430       ("(" ^ UnparseC.term_in_thy thy t1 ^ ")") ("(" ^ UnparseC.term_in_thy thy t2 ^ ")"), 
   431       HOLogic.Trueprop $ (TermC.mk_equality (t, @{term True})))
   432   else
   433     (case (TermC.is_atom t1, TermC.is_atom t2) of
   434       (true, true) =>
   435         if TermC.variable_constant_pair (t1, t2)
   436         then NONE
   437         else SOME (TermC.mk_thmid thmid
   438           ("(" ^ UnparseC.term_in_thy thy t1 ^ ")") ("(" ^ UnparseC.term_in_thy thy t2 ^ ")"),
   439           HOLogic.Trueprop $ (TermC.mk_equality (t, @{term False})))
   440     | _ => NONE)                                              (* NOT is_atom t1,t2 --> rew_sub *)
   441   | eval_equal _ _ _ _ = NONE;                                                   (* error-exit *)
   442 
   443 (*. evaluate HOL.divide .*)
   444 (*("DIVIDE" ,("Rings.divide_class.divide"  , eval_cancel "#divide_e"))*)
   445 fun eval_cancel thmid "Rings.divide_class.divide" (t as (Const _ $ t1 $ t2)) _ = 
   446     if TermC.is_num t1 andalso TermC.is_num t2 then
   447       let
   448         val (T, _) = HOLogic.dest_number t1;
   449         val (i1, i2) = (Eval.int_of_numeral t1, Eval.int_of_numeral t2);
   450         val res_int as (_, (i1', i2')) = Eval.cancel_int (i1, i2);
   451       in
   452         if (i1', i2') = (i1, i2) then NONE
   453         else
   454           let
   455             val res = TermC.mk_frac T res_int;
   456             val prop = HOLogic.Trueprop $ (HOLogic.mk_eq (t, res));
   457           in SOME (TermC.mk_thmid thmid (string_of_int i1) (string_of_int i2), prop) end
   458       end
   459     else NONE
   460   | eval_cancel _ _ _ _ = NONE;
   461 
   462 (* get the argument from a function-definition *)
   463 (*("argument_in" ,("Prog_Expr.argument_in", Prog_Expr.eval_argument_in "Prog_Expr.argument_in"))*)
   464 fun eval_argument_in _ "Prog_Expr.argument_in" 
   465 		 (t as (Const ("Prog_Expr.argument_in", _) $ (_(*f*) $ arg))) _ =
   466     if is_Free arg (*could be something to be simplified before*)
   467     then
   468       SOME (UnparseC.term t ^ " = " ^ UnparseC.term arg,
   469 	      HOLogic.Trueprop $ (TermC.mk_equality (t, arg)))
   470     else NONE
   471   | eval_argument_in _ _ _ _ = NONE;
   472 
   473 (* check if the function-identifier of the first argument matches 
   474    the function-identifier of the lhs of the second argument *)
   475 (*("sameFunId" ,("Prog_Expr.sameFunId", eval_same_funid "Prog_Expr.sameFunId"))*)
   476 fun eval_sameFunId _ "Prog_Expr.sameFunId" 
   477 		     (p as Const ("Prog_Expr.sameFunId",_) $  (f1 $ _) $ (Const (\<^const_name>\<open>HOL.eq\<close>, _) $ (f2 $ _) $ _)) _ =
   478     if f1 = f2 
   479     then SOME ((UnparseC.term p) ^ " = True",
   480 	       HOLogic.Trueprop $ (TermC.mk_equality (p, @{term True})))
   481     else SOME ((UnparseC.term p) ^ " = False",
   482 	       HOLogic.Trueprop $ (TermC.mk_equality (p, @{term False})))
   483 | eval_sameFunId _ _ _ _ = NONE;
   484 
   485 
   486 (*.from a list of fun-definitions "f x = ..." as 2nd argument
   487    filter the elements with the same fun-identfier in "f y"
   488    as the fst argument;
   489    this is, because Isabelles filter takes more than 1 sec.*)
   490 fun same_funid f1 (Const (\<^const_name>\<open>HOL.eq\<close>, _) $ (f2 $ _) $ _) = f1 = f2
   491   | same_funid f1 t = raise ERROR ("same_funid called with t = ("
   492 		  ^ UnparseC.term f1 ^ ") (" ^ UnparseC.term t ^ ")");
   493 (*("filter_sameFunId" ,("Prog_Expr.filter_sameFunId",
   494 		   eval_filter_sameFunId "Prog_Expr.filter_sameFunId"))*)
   495 fun eval_filter_sameFunId _ "Prog_Expr.filter_sameFunId" 
   496 		     (p as Const ("Prog_Expr.filter_sameFunId",_) $ 
   497 			(fid $ _) $ fs) _ =
   498     let val fs' = ((TermC.list2isalist HOLogic.boolT) o 
   499 		   (filter (same_funid fid))) (TermC.isalist2list fs)
   500     in SOME (UnparseC.term (TermC.mk_equality (p, fs')),
   501 	       HOLogic.Trueprop $ (TermC.mk_equality (p, fs'))) end
   502 | eval_filter_sameFunId _ _ _ _ = NONE;
   503 
   504 (* make a list of terms to a sum *)
   505 fun list2sum [] = raise ERROR ("list2sum called with []")
   506   | list2sum [s] = s
   507   | list2sum (s::ss) = 
   508     let
   509       fun sum su [s'] = Const (\<^const_name>\<open>plus\<close>,
   510            [HOLogic.realT,HOLogic.realT] ---> HOLogic.realT) $ su $ s'
   511     	  | sum su (s'::ss') = sum (Const (\<^const_name>\<open>plus\<close>,
   512            [HOLogic.realT,HOLogic.realT] ---> HOLogic.realT) $ su $ s') ss'
   513     	  | sum _ _ = raise ERROR "list2sum: pattern in fun.def is missing" 
   514     in sum s ss end;
   515 
   516 (* make a list of equalities to the sum of the lhs *)
   517 (*("boollist2sum"    ,("Prog_Expr.boollist2sum"    , eval_boollist2sum "")):calc*)
   518 fun eval_boollist2sum _ "Prog_Expr.boollist2sum" 
   519 		  (p as Const ("Prog_Expr.boollist2sum", _) $ (l as Const (\<^const_name>\<open>Cons\<close>, _) $ _ $ _)) _ =
   520     let
   521       val isal = TermC.isalist2list l
   522 	    val lhss = map lhs isal
   523 	    val sum = list2sum lhss
   524     in
   525       SOME ((UnparseC.term p) ^ " = " ^ (UnparseC.term sum),
   526 	      HOLogic.Trueprop $ (TermC.mk_equality (p, sum)))
   527     end
   528   | eval_boollist2sum _ _ _ _ = NONE;
   529 
   530 (**) end (*struct*)
   531 \<close> text \<open>
   532 open Prog_Expr
   533 \<close> ML \<open>
   534 \<close> ML \<open>
   535 \<close>
   536 
   537 subsection \<open>extend rule-set for evaluating pre-conditions and program-expressions\<close>
   538 ML \<open>
   539 val prog_expr = Rule_Set.append_rules "prog_expr" prog_expr [\<^rule_eval>\<open>Prog_Expr.rhs\<close> (Prog_Expr.eval_rhs "")];
   540 \<close> ML \<open>
   541 \<close> ML \<open>
   542 \<close>
   543 
   544 subsection \<open>setup for rule-sets and ML-functions\<close>
   545 
   546 rule_set_knowledge prog_expr = prog_expr
   547 
   548 calculation matches = \<open>Prog_Expr.eval_matches "#matches_"\<close>
   549 calculation matchsub = \<open>Prog_Expr.eval_matchsub "#matchsub_"\<close>
   550 calculation Vars = \<open>Prog_Expr.eval_var "#Vars_"\<close>
   551 calculation lhs = \<open>Prog_Expr.eval_lhs ""\<close>
   552 calculation rhs = \<open>Prog_Expr.eval_rhs ""\<close>
   553 (*\\------------------------- from Tools .thy-------------------------------------------------//*)
   554 ML \<open>
   555 \<close> ML \<open>
   556 \<close> ML \<open>
   557 \<close>
   558 
   559 end