src/HOL/Tools/res_clause.ML
author mengj
Wed Dec 14 06:19:33 2005 +0100 (2005-12-14)
changeset 18403 df0c0f35c897
parent 18402 aaba095cf62b
child 18409 080094128a09
permissions -rw-r--r--
Changed literals' ordering and the functions for sorting literals.
     1 (*  Author: Jia Meng, Cambridge University Computer Laboratory
     2 
     3     ID: $Id$
     4     Copyright 2004 University of Cambridge
     5 
     6 ML data structure for storing/printing FOL clauses and arity clauses.
     7 Typed equality is treated differently.
     8 *)
     9 
    10 (* works for writeoutclasimp on typed *)
    11 signature RES_CLAUSE =
    12   sig
    13   val keep_types : bool ref
    14   val special_equal : bool ref
    15   val tagged : bool ref
    16 
    17   exception ARCLAUSE of string
    18   exception CLAUSE of string * term
    19   type arityClause 
    20   type classrelClause
    21   type clause
    22   val init : theory -> unit
    23   val make_axiom_clause : Term.term -> string * int -> clause
    24   val make_conjecture_clauses : term list -> clause list
    25   val get_axiomName : clause ->  string
    26   val isTaut : clause -> bool
    27   val num_of_clauses : clause -> int
    28 
    29   val clause2dfg : clause -> string * string list
    30   val clauses2dfg : clause list -> string -> clause list -> clause list ->
    31 	   (string * int) list -> (string * int) list -> string
    32   val tfree_dfg_clause : string -> string
    33 
    34   val arity_clause_thy: theory -> arityClause list 
    35   val classrel_clauses_thy: theory -> classrelClause list 
    36 
    37   val tptp_arity_clause : arityClause -> string
    38   val tptp_classrelClause : classrelClause -> string
    39   val tptp_clause : clause -> string list
    40   val clause2tptp : clause -> string * string list
    41   val tfree_clause : string -> string
    42   val schematic_var_prefix : string
    43   val fixed_var_prefix : string
    44   val tvar_prefix : string
    45   val tfree_prefix : string
    46   val clause_prefix : string 
    47   val arclause_prefix : string
    48   val const_prefix : string
    49   val tconst_prefix : string 
    50   val class_prefix : string 
    51 
    52   val union_all : ''a list list -> ''a list
    53   val ascii_of : String.string -> String.string
    54   val paren_pack : string list -> string
    55   val bracket_pack : string list -> string
    56   val make_schematic_var : String.string * int -> string
    57   val make_fixed_var : String.string -> string
    58   val make_schematic_type_var : string * int -> string
    59   val make_fixed_type_var : string -> string
    60   val make_fixed_const : String.string -> string		
    61   val make_fixed_type_const : String.string -> string   
    62   val make_type_class : String.string -> string
    63   val isMeta : String.string -> bool
    64   
    65   type typ_var
    66   val mk_typ_var_sort : Term.typ -> typ_var * sort
    67   type type_literal
    68   val add_typs_aux2 : (typ_var * string list) list -> type_literal list * type_literal list
    69   val gen_tptp_cls : int * string * string * string -> string
    70   val gen_tptp_type_cls : int * string * string * string * int -> string
    71   val tptp_of_typeLit : type_literal -> string
    72 
    73   end;
    74 
    75 structure ResClause: RES_CLAUSE =
    76 struct
    77 
    78 (* Added for typed equality *)
    79 val special_equal = ref false; (* by default,equality does not carry type information *)
    80 val eq_typ_wrapper = "typeinfo"; (* default string *)
    81 
    82 
    83 val schematic_var_prefix = "V_";
    84 val fixed_var_prefix = "v_";
    85 
    86 val tvar_prefix = "T_";
    87 val tfree_prefix = "t_";
    88 
    89 val clause_prefix = "cls_"; 
    90 val arclause_prefix = "clsarity_" 
    91 val clrelclause_prefix = "clsrel_";
    92 
    93 val const_prefix = "c_";
    94 val tconst_prefix = "tc_"; 
    95 
    96 val class_prefix = "class_"; 
    97 
    98 
    99 fun union_all xss = foldl (op union) [] xss;
   100 
   101  
   102 (*Provide readable names for the more common symbolic functions*)
   103 val const_trans_table =
   104       Symtab.make [("op =", "equal"),
   105 	  	   ("op <=", "lessequals"),
   106 		   ("op <", "less"),
   107 		   ("op &", "and"),
   108 		   ("op |", "or"),
   109 		   ("op +", "plus"),
   110 		   ("op -", "minus"),
   111 		   ("op *", "times"),
   112 		   ("op -->", "implies"),
   113 		   ("{}", "emptyset"),
   114 		   ("op :", "in"),
   115 		   ("op Un", "union"),
   116 		   ("op Int", "inter"),
   117 		   ("List.op @", "append")];
   118 
   119 val type_const_trans_table =
   120       Symtab.make [("*", "t_prod"),
   121 	  	   ("+", "t_sum"),
   122 		   ("~=>", "t_map")];
   123 
   124 (*Escaping of special characters.
   125   Alphanumeric characters are left unchanged.
   126   The character _ goes to __
   127   Characters in the range ASCII space to / go to _A to _P, respectively.
   128   Other printing characters go to _NNN where NNN is the decimal ASCII code.*)
   129 local
   130 
   131 val A_minus_space = Char.ord #"A" - Char.ord #" ";
   132 
   133 fun ascii_of_c c =
   134   if Char.isAlphaNum c then String.str c
   135   else if c = #"_" then "__"
   136   else if #" " <= c andalso c <= #"/" 
   137        then "_" ^ String.str (Char.chr (Char.ord c + A_minus_space))
   138   else if Char.isPrint c then ("_" ^ Int.toString (Char.ord c))
   139   else ""
   140 
   141 in
   142 
   143 val ascii_of = String.translate ascii_of_c;
   144 
   145 end;
   146 
   147 (* convert a list of strings into one single string; surrounded by brackets *)
   148 fun paren_pack [] = ""   (*empty argument list*)
   149   | paren_pack strings = "(" ^ commas strings ^ ")";
   150 
   151 fun bracket_pack strings = "[" ^ commas strings ^ "]";
   152 
   153 
   154 (*Remove the initial ' character from a type variable, if it is present*)
   155 fun trim_type_var s =
   156   if s <> "" andalso String.sub(s,0) = #"'" then String.extract(s,1,NONE)
   157   else error ("trim_type: Malformed type variable encountered: " ^ s);
   158 
   159 fun ascii_of_indexname (v,0) = ascii_of v
   160   | ascii_of_indexname (v,i) = ascii_of v ^ "_" ^ Int.toString i;
   161 
   162 fun make_schematic_var v = schematic_var_prefix ^ (ascii_of_indexname v);
   163 fun make_fixed_var x = fixed_var_prefix ^ (ascii_of x);
   164 
   165 fun make_schematic_type_var (x,i) = 
   166       tvar_prefix ^ (ascii_of_indexname (trim_type_var x,i));
   167 fun make_fixed_type_var x = tfree_prefix ^ (ascii_of (trim_type_var x));
   168 
   169 fun make_fixed_const c =
   170     case Symtab.lookup const_trans_table c of
   171         SOME c' => c'
   172       | NONE =>  const_prefix ^ ascii_of c;
   173 
   174 fun make_fixed_type_const c = 
   175     case Symtab.lookup type_const_trans_table c of
   176         SOME c' => c'
   177       | NONE =>  tconst_prefix ^ ascii_of c;
   178 
   179 fun make_type_class clas = class_prefix ^ ascii_of clas;
   180 
   181 
   182 
   183 (***** definitions and functions for FOL clauses, prepared for conversion into TPTP format or SPASS format. *****)
   184 
   185 val keep_types = ref true;
   186 
   187 datatype kind = Axiom | Hypothesis | Conjecture;
   188 fun name_of_kind Axiom = "axiom"
   189   | name_of_kind Hypothesis = "hypothesis"
   190   | name_of_kind Conjecture = "conjecture";
   191 
   192 type clause_id = int;
   193 type axiom_name = string;
   194 
   195 
   196 type polarity = bool;
   197 
   198 type indexname = Term.indexname;
   199 
   200 
   201 (* "tag" is used for vampire specific syntax  *)
   202 type tag = bool; 
   203 
   204 
   205 (**** Isabelle FOL clauses ****)
   206 
   207 val tagged = ref false;
   208 
   209 type pred_name = string;
   210 type sort = Term.sort;
   211 
   212 
   213 
   214 datatype typ_var = FOLTVar of indexname | FOLTFree of string;
   215 
   216 datatype fol_type = AtomV of string
   217 		  | AtomF of string
   218 		  | Comp of string * fol_type list;
   219 
   220 fun string_of_fol_type (AtomV x) = x
   221   | string_of_fol_type (AtomF x) = x
   222   | string_of_fol_type (Comp(tcon,tps)) = 
   223     let val tstrs = map string_of_fol_type tps
   224     in
   225 	tcon ^ (paren_pack tstrs)
   226     end;
   227 
   228 
   229 datatype type_literal = LTVar of string | LTFree of string;
   230 
   231 datatype folTerm = UVar of string * fol_type
   232                  | Fun of string * fol_type list * folTerm list;
   233 datatype predicate = Predicate of pred_name * fol_type list * folTerm list;
   234 
   235 datatype literal = Literal of polarity * predicate * tag;
   236 
   237 fun mk_typ_var_sort (TFree(a,s)) = (FOLTFree a,s)
   238   | mk_typ_var_sort (TVar(v,s)) = (FOLTVar v,s);
   239 
   240 
   241 
   242 (* ML datatype used to repsent one single clause: disjunction of literals. *)
   243 datatype clause = 
   244 	 Clause of {clause_id: clause_id,
   245 		    axiom_name: axiom_name,
   246 		    kind: kind,
   247 		    literals: literal list,
   248 		    types_sorts: (typ_var * sort) list, 
   249                     tvar_type_literals: type_literal list, 
   250                     tfree_type_literals: type_literal list ,
   251                     tvars: string list,
   252                     predicates: (string*int) list,
   253                     functions: (string*int) list};
   254 
   255 
   256 exception CLAUSE of string * term;
   257 
   258 fun get_literals (c as Clause(cls)) = #literals cls;
   259 
   260 fun components_of_literal (Literal (pol,pred,tag)) = ((pol,pred),tag);
   261 
   262 fun predicate_name (Predicate(predname,_,_)) = predname;
   263 
   264 
   265 (*** make clauses ***)
   266 
   267 fun isFalse (Literal (pol,Predicate(a,_,[]),_)) =
   268       (pol andalso a = "c_False") orelse
   269       (not pol andalso a = "c_True")
   270   | isFalse _ = false;
   271 
   272 fun isTrue (Literal (pol,Predicate(a,_,[]),_)) =
   273       (pol andalso a = "c_True") orelse
   274       (not pol andalso a = "c_False")
   275   | isTrue _ = false;
   276   
   277 fun isTaut (Clause {literals,...}) = exists isTrue literals;  
   278 
   279 fun make_clause (clause_id,axiom_name,kind,literals,
   280                  types_sorts,tvar_type_literals,
   281                  tfree_type_literals,tvars, predicates, functions) =
   282   if forall isFalse literals 
   283   then error "Problem too trivial for resolution (empty clause)"
   284   else
   285      Clause {clause_id = clause_id, axiom_name = axiom_name, kind = kind, 
   286              literals = literals, types_sorts = types_sorts,
   287              tvar_type_literals = tvar_type_literals,
   288              tfree_type_literals = tfree_type_literals,
   289              tvars = tvars, predicates = predicates, 
   290              functions = functions};
   291 
   292 
   293 (** Some Clause destructor functions **)
   294 
   295 fun string_of_kind (Clause cls) = name_of_kind (#kind cls);
   296 
   297 fun get_axiomName (Clause cls) = #axiom_name cls;
   298 
   299 fun get_clause_id (Clause cls) = #clause_id cls;
   300 
   301 fun funcs_of_cls (Clause cls) = #functions cls;
   302 
   303 fun preds_of_cls (Clause cls) = #predicates cls;
   304 
   305 
   306 (*Declarations of the current theory--to allow suppressing types.*)
   307 val const_typargs = ref (Library.K [] : (string*typ -> typ list));
   308 
   309 fun num_typargs(s,T) = if !keep_types then length (!const_typargs (s,T)) else 0;
   310 
   311 (*Initialize the type suppression mechanism with the current theory before
   312     producing any clauses!*)
   313 fun init thy = (const_typargs := Sign.const_typargs thy);
   314     
   315 
   316 (*Flatten a type to a fol_type while accumulating sort constraints on the TFrees and
   317   TVars it contains.*)    
   318 fun type_of (Type (a, Ts)) = 
   319       let val (folTyps, (ts, funcs)) = types_of Ts 
   320 	  val t = make_fixed_type_const a
   321       in    
   322 	  (Comp(t,folTyps), (ts, (t, length Ts)::funcs))
   323       end
   324   | type_of (TFree (a,s)) = 
   325       let val t = make_fixed_type_var a
   326       in (AtomF(t), ([((FOLTFree a),s)], [(t,0)])) end
   327   | type_of (TVar (v, s)) = (AtomV(make_schematic_type_var v), ([((FOLTVar v),s)], []))
   328 and types_of Ts =
   329       let val foltyps_ts = map type_of Ts 
   330 	  val (folTyps,ts_funcs) = ListPair.unzip foltyps_ts
   331 	  val (ts, funcslist) = ListPair.unzip ts_funcs
   332       in    
   333 	  (folTyps, (union_all ts, union_all funcslist))
   334       end;
   335 
   336 
   337 fun const_types_of (c,T) = types_of (!const_typargs (c,T));
   338 
   339 (* Any variables created via the METAHYPS tactical should be treated as
   340    universal vars, although it is represented as "Free(...)" by Isabelle *)
   341 val isMeta = String.isPrefix "METAHYP1_"
   342 
   343 fun pred_name_type (Const(c,T)) = 
   344       let val (contys,(folTyps,funcs)) = const_types_of (c,T)
   345       in (make_fixed_const c, (contys,folTyps), funcs) end
   346   | pred_name_type (Free(x,T))  = 
   347       if isMeta x then raise CLAUSE("Predicate Not First Order 1", Free(x,T)) 
   348       else (make_fixed_var x, ([],[]), [])
   349   | pred_name_type (v as Var _) = raise CLAUSE("Predicate Not First Order 2", v)
   350   | pred_name_type t        = raise CLAUSE("Predicate input unexpected", t);
   351 
   352 
   353 (* For typed equality *)
   354 (* here "arg_typ" is the type of "="'s argument's type, not the type of the equality *)
   355 (* Find type of equality arg *)
   356 fun eq_arg_type (Type("fun",[T,_])) = 
   357     let val (folT,_) = type_of T;
   358     in  folT  end;
   359 
   360 fun fun_name_type (Const("op =",T)) args =   (*FIXME: Is this special treatment of = needed??*)
   361       let val t = make_fixed_const "op ="
   362       in (t, ([eq_arg_type T], []), [(t,2)]) end
   363   | fun_name_type (Const(c,T)) args = 
   364       let val t = make_fixed_const c
   365 	  val (contys, (folTyps,funcs)) = const_types_of (c,T)
   366 	  val arity = num_typargs(c,T) + length args
   367       in
   368 	  (t, (contys,folTyps), ((t,arity)::funcs))
   369       end
   370  | fun_name_type (Free(x,T)) args  = 
   371       let val t = make_fixed_var x
   372       in  (t, ([],[]), [(t, length args)]) end
   373   | fun_name_type f args = raise CLAUSE("Function Not First Order 1", f);
   374 
   375 
   376 fun term_of (Var(ind_nm,T)) = 
   377       let val (folType,(ts,funcs)) = type_of T
   378       in
   379 	  (UVar(make_schematic_var ind_nm, folType), (ts, funcs))
   380       end
   381   | term_of (Free(x,T)) = 
   382       let val (folType, (ts,funcs)) = type_of T
   383       in
   384 	  if isMeta x then (UVar(make_schematic_var(x,0),folType),
   385 			    (ts, ((make_schematic_var(x,0)),0)::funcs))
   386 	  else
   387 	      (Fun(make_fixed_var x, [folType], []), 
   388 	       (ts, ((make_fixed_var x),0)::funcs))
   389       end
   390   | term_of (Const(c,T)) =  (* impossible to be equality *)
   391       let val (contys, (folTyps,funcs)) = const_types_of (c,T)
   392       in
   393 	  (Fun(make_fixed_const c, contys, []),
   394 	   (folTyps, ((make_fixed_const c),0)::funcs))
   395       end    
   396   | term_of app = 
   397       let val (f,args) = strip_comb app
   398           val _ = case f of Const(_,_) => ()
   399 			  | Free(s,_)  => 
   400 			      if isMeta s 
   401 			      then raise CLAUSE("Function Not First Order 2", f)
   402 			      else ()
   403 			  | _ => raise CLAUSE("Function Not First Order 3", f);
   404 	  val (funName,(contys,ts1),funcs) = fun_name_type f args
   405 	  val (args',(ts2,funcs')) = terms_of args
   406       in
   407 	  (Fun(funName,contys,args'), 
   408 	   (union_all (ts1::ts2), 
   409 	    union_all(funcs::funcs')))
   410       end
   411   | term_of t = raise CLAUSE("Function Not First Order 4", t)
   412 and terms_of ts =  
   413       let val (args, ts_funcs) = ListPair.unzip (map term_of ts)
   414       in
   415 	  (args, ListPair.unzip ts_funcs)
   416       end
   417 
   418 
   419 fun pred_of (Const("op =", typ), args) =
   420       let val arg_typ = eq_arg_type typ 
   421 	  val (args',(ts,funcs)) = terms_of args
   422 	  val equal_name = make_fixed_const "op ="
   423       in
   424 	  (Predicate(equal_name,[arg_typ],args'),
   425 	   union_all ts, 
   426 	   [((make_fixed_var equal_name), 2)], 
   427 	   union_all funcs)
   428       end
   429   | pred_of (pred,args) = 
   430       let val (predName,(predType,ts1), pfuncs) = pred_name_type pred
   431 	  val (args',(ts2,ffuncs)) = terms_of args
   432 	  val ts3 = union_all (ts1::ts2)
   433 	  val ffuncs' = union_all ffuncs
   434 	  val newfuncs = pfuncs union ffuncs'
   435 	  val arity = 
   436 	    case pred of
   437 		Const (c,T) => num_typargs(c,T) + length args
   438 	      | _ => length args
   439       in
   440 	  (Predicate(predName,predType,args'), ts3, 
   441 	   [(predName, arity)], newfuncs)
   442       end;
   443 
   444 
   445 (*Treatment of literals, possibly negated or tagged*)
   446 fun predicate_of ((Const("Not",_) $ P), polarity, tag) =
   447       predicate_of (P, not polarity, tag)
   448   | predicate_of ((Const("HOL.tag",_) $ P), polarity, tag) =
   449       predicate_of (P, polarity, true)
   450   | predicate_of (term,polarity,tag) =
   451         (pred_of (strip_comb term), polarity, tag);
   452 
   453 fun literals_of_term1 args (Const("Trueprop",_) $ P) = literals_of_term1 args P
   454   | literals_of_term1 (args as (lits, ts, preds, funcs)) (Const("op |",_) $ P $ Q) = 
   455       let val (lits', ts', preds', funcs') = literals_of_term1 args P
   456       in
   457 	  literals_of_term1 (lits', ts', preds' union preds, funcs' union funcs) Q
   458       end
   459   | literals_of_term1 (lits, ts, preds, funcs) P =
   460       let val ((pred, ts', preds', funcs'), pol, tag) = predicate_of (P,true,false)
   461 	  val lits' = Literal(pol,pred,tag) :: lits
   462       in
   463 	  (lits', ts union ts', preds' union preds, funcs' union funcs)
   464       end;
   465 
   466 
   467 val literals_of_term = literals_of_term1 ([],[],[],[]);
   468 
   469 
   470 
   471 fun list_ord _ ([],[]) = EQUAL
   472   | list_ord _ ([],_) = LESS
   473   | list_ord _ (_,[]) = GREATER
   474   | list_ord ord (x::xs, y::ys) =
   475     let val xy_ord = ord(x,y)
   476     in
   477 	case xy_ord of EQUAL => list_ord ord (xs,ys)
   478 		     | _ => xy_ord
   479     end;
   480 
   481 fun type_ord (AtomV(_),AtomV(_)) = EQUAL
   482   | type_ord (AtomV(_),_) = LESS
   483   | type_ord (AtomF(_),AtomV(_)) = GREATER
   484   | type_ord (AtomF(f1),AtomF(f2)) = string_ord (f1,f2)
   485   | type_ord (AtomF(_),_) = LESS
   486   | type_ord (Comp(_,_),AtomV(_)) = GREATER
   487   | type_ord (Comp(_,_),AtomF(_)) = GREATER
   488   | type_ord (Comp(con1,args1),Comp(con2,args2)) = 
   489     let val con_ord = string_ord(con1,con2)
   490     in
   491 	case con_ord of EQUAL => types_ord (args1,args2)
   492 		      | _ => con_ord
   493     end
   494 and
   495 
   496 types_ord ([],[]) = EQUAL
   497   | types_ord (tps1,tps2) = list_ord type_ord (tps1,tps2);
   498 
   499 
   500 fun term_ord (UVar(_,_),UVar(_,_)) = EQUAL
   501   | term_ord (UVar(_,_),_) = LESS
   502   | term_ord (Fun(_,_,_),UVar(_)) = GREATER
   503   | term_ord (Fun(f1,tps1,tms1),Fun(f2,tps2,tms2)) = 
   504     let val fn_ord = string_ord (f1,f2)
   505     in
   506 	case fn_ord of EQUAL => 
   507 		       let val tms_ord = terms_ord (tms1,tms2)
   508 		       in
   509 			   case tms_ord of EQUAL => types_ord (tps1,tps2)
   510 					 | _ => tms_ord
   511 		       end
   512 		     | _ => fn_ord
   513     end
   514 
   515 and
   516 
   517 terms_ord ([],[]) = EQUAL
   518   | terms_ord (tms1,tms2) = list_ord term_ord (tms1,tms2);
   519 
   520 
   521 
   522 fun predicate_ord (Predicate(predname1,ftyps1,ftms1),Predicate(predname2,ftyps2,ftms2)) = 
   523     let val predname_ord = string_ord (predname1,predname2)
   524     in
   525 	case predname_ord of EQUAL => 
   526 			     let val ftms_ord = terms_ord(ftms1,ftms2)
   527 			     in
   528 				 case ftms_ord of EQUAL => types_ord(ftyps1,ftyps2)
   529 						| _ => ftms_ord
   530 			     end
   531 			   | _ => predname_ord
   532     end;
   533 
   534 fun literal_ord (Literal(false,_,_),Literal(true,_,_)) = LESS
   535   | literal_ord (Literal(true,_,_),Literal(false,_,_)) = GREATER
   536   | literal_ord (Literal(_,pred1,_),Literal(_,pred2,_)) = predicate_ord(pred1,pred2);
   537 
   538 fun sort_lits lits = sort literal_ord lits;
   539 
   540 
   541 
   542 (* FIX: not sure what to do with these funcs *)
   543 
   544 (*Make literals for sorted type variables*) 
   545 fun sorts_on_typs (_, [])   = ([]) 
   546   | sorts_on_typs (v, "HOL.type" :: s) =
   547       sorts_on_typs (v,s)   (*Ignore sort "type"*)
   548   | sorts_on_typs ((FOLTVar indx), (s::ss)) =
   549       LTVar((make_type_class s) ^ 
   550         "(" ^ (make_schematic_type_var indx) ^ ")") :: 
   551       (sorts_on_typs ((FOLTVar indx), ss))
   552   | sorts_on_typs ((FOLTFree x), (s::ss)) =
   553       LTFree((make_type_class s) ^ "(" ^ (make_fixed_type_var x) ^ ")") :: 
   554       (sorts_on_typs ((FOLTFree x), ss));
   555 
   556 
   557 (*UGLY: seems to be parsing the "show sorts" output, removing anything that
   558   starts with a left parenthesis.*)
   559 fun remove_type str = hd (String.fields (fn c => c = #"(") str);
   560 
   561 fun pred_of_sort (LTVar x) = ((remove_type x),1)
   562 |   pred_of_sort (LTFree x) = ((remove_type x),1)
   563 
   564 
   565 
   566 
   567 (*Given a list of sorted type variables, return two separate lists.
   568   The first is for TVars, the second for TFrees.*)
   569 fun add_typs_aux [] preds  = ([],[], preds)
   570   | add_typs_aux ((FOLTVar indx,s)::tss) preds = 
   571       let val vs = sorts_on_typs (FOLTVar indx, s)
   572           val preds' = (map pred_of_sort vs)@preds
   573 	  val (vss,fss, preds'') = add_typs_aux tss preds'
   574       in
   575 	  (vs union vss, fss, preds'')
   576       end
   577   | add_typs_aux ((FOLTFree x,s)::tss) preds  =
   578       let val fs = sorts_on_typs (FOLTFree x, s)
   579           val preds' = (map pred_of_sort fs)@preds
   580 	  val (vss,fss, preds'') = add_typs_aux tss preds'
   581       in
   582 	  (vss, fs union fss, preds'')
   583       end;
   584 
   585 fun add_typs_aux2 [] = ([],[])
   586   | add_typs_aux2 ((FOLTVar indx,s)::tss) =
   587     let val vs = sorts_on_typs (FOLTVar indx,s)
   588 	val (vss,fss) = add_typs_aux2 tss
   589     in
   590 	(vs union vss,fss)
   591     end
   592   | add_typs_aux2 ((FOLTFree x,s)::tss) =
   593     let val fs = sorts_on_typs (FOLTFree x,s)
   594 	val (vss,fss) = add_typs_aux2 tss
   595     in
   596 	(vss,fs union fss)
   597     end;
   598 
   599 
   600 fun add_typs (Clause cls) preds  = add_typs_aux (#types_sorts cls) preds 
   601 
   602 
   603 (** make axiom clauses, hypothesis clauses and conjecture clauses. **)
   604 
   605 fun get_tvar_strs [] = []
   606   | get_tvar_strs ((FOLTVar indx,s)::tss) = 
   607       let val vstr = make_schematic_type_var indx
   608       in
   609 	  vstr ins (get_tvar_strs tss)
   610       end
   611   | get_tvar_strs((FOLTFree x,s)::tss) = distinct (get_tvar_strs tss)
   612 
   613 (* FIX add preds and funcs to add typs aux here *)
   614 
   615 fun make_axiom_clause_thm thm (ax_name,cls_id) =
   616     let val (lits,types_sorts, preds, funcs) = literals_of_term (prop_of thm)
   617 	val lits' = sort_lits lits
   618 	val (tvar_lits,tfree_lits, preds) = add_typs_aux types_sorts preds 
   619         val tvars = get_tvar_strs types_sorts
   620     in 
   621 	make_clause(cls_id,ax_name,Axiom,
   622 	            lits',types_sorts,tvar_lits,tfree_lits,
   623 	            tvars, preds, funcs)
   624     end;
   625 
   626 
   627 (* check if a clause is FOL first*)
   628 fun make_conjecture_clause n t =
   629     let val _ = check_is_fol_term t
   630 	    handle TERM("check_is_fol_term",_) => raise CLAUSE("Goal is not FOL",t)
   631 	val (lits,types_sorts, preds, funcs) = literals_of_term t
   632 	val (tvar_lits,tfree_lits, preds) = add_typs_aux types_sorts preds 
   633         val tvars = get_tvar_strs types_sorts
   634     in
   635 	make_clause(n,"conjecture",Conjecture,
   636 	            lits,types_sorts,tvar_lits,tfree_lits,
   637 	            tvars, preds, funcs)
   638     end;
   639     
   640 fun make_conjecture_clauses_aux _ [] = []
   641   | make_conjecture_clauses_aux n (t::ts) =
   642       make_conjecture_clause n t :: make_conjecture_clauses_aux (n+1) ts
   643 
   644 val make_conjecture_clauses = make_conjecture_clauses_aux 0
   645 
   646 
   647 (*before converting an axiom clause to "clause" format, check if it is FOL*)
   648 fun make_axiom_clause term (ax_name,cls_id) =
   649     let val _ = check_is_fol_term term 
   650 	    handle TERM("check_is_fol_term",_) => raise CLAUSE("Axiom is not FOL", term) 
   651 	val (lits,types_sorts, preds,funcs) = literals_of_term term
   652 	val lits' = sort_lits lits
   653 	val (tvar_lits,tfree_lits, preds) = add_typs_aux types_sorts preds
   654         val tvars = get_tvar_strs types_sorts	
   655     in 
   656 	make_clause(cls_id,ax_name,Axiom,
   657 	            lits',types_sorts,tvar_lits,tfree_lits,
   658 	            tvars, preds,funcs)
   659     end;
   660 
   661 
   662 
   663  
   664 (**** Isabelle arities ****)
   665 
   666 exception ARCLAUSE of string;
   667  
   668 
   669 type class = string; 
   670 type tcons = string; 
   671 
   672 
   673 datatype arLit = TConsLit of bool * (class * tcons * string list) | TVarLit of bool * (class * string);
   674  
   675 datatype arityClause =  
   676 	 ArityClause of {clause_id: clause_id,
   677 	  	         axiom_name: axiom_name,
   678 			 kind: kind,
   679 			 conclLit: arLit,
   680 			 premLits: arLit list};
   681 
   682 
   683 fun get_TVars 0 = []
   684   | get_TVars n = ("T_" ^ (Int.toString n)) :: get_TVars (n-1);
   685 
   686 
   687 
   688 fun pack_sort(_,[])  = raise ARCLAUSE("Empty Sort Found") 
   689   | pack_sort(tvar, [cls]) = [(make_type_class cls, tvar)] 
   690   | pack_sort(tvar, cls::srt) =  (make_type_class cls,tvar) :: (pack_sort(tvar, srt));
   691     
   692     
   693 fun make_TVarLit (b,(cls,str)) = TVarLit(b,(cls,str));
   694 fun make_TConsLit (b,(cls,tcons,tvars)) = TConsLit(b,(make_type_class cls,make_fixed_type_const tcons,tvars));
   695 
   696 fun make_axiom_arity_clause (tcons,n,(res,args)) =
   697    let val nargs = length args
   698        val tvars = get_TVars nargs
   699        val tvars_srts = ListPair.zip (tvars,args)
   700        val tvars_srts' = union_all(map pack_sort tvars_srts)
   701        val false_tvars_srts' = map (pair false) tvars_srts'
   702    in
   703       ArityClause {clause_id = n, kind = Axiom, 
   704                    axiom_name = tcons,
   705                    conclLit = make_TConsLit(true,(res,tcons,tvars)), 
   706                    premLits = map make_TVarLit false_tvars_srts'}
   707    end;
   708     
   709 (*The number of clauses generated from cls, including type clauses*)
   710 fun num_of_clauses (Clause cls) =
   711     let val num_tfree_lits = 
   712 	      if !keep_types then length (#tfree_type_literals cls)
   713 	      else 0
   714     in 	1 + num_tfree_lits  end;
   715 
   716 
   717 (**** Isabelle class relations ****)
   718 
   719 
   720 datatype classrelClause = 
   721 	 ClassrelClause of {clause_id: clause_id,
   722 			    subclass: class,
   723 			    superclass: class option};
   724 
   725 
   726 fun make_axiom_classrelClause n subclass superclass =
   727   ClassrelClause {clause_id = n,
   728                   subclass = subclass, superclass = superclass};
   729 
   730 
   731 fun classrelClauses_of_aux n sub [] = []
   732   | classrelClauses_of_aux n sub (sup::sups) =
   733       make_axiom_classrelClause n sub (SOME sup) :: classrelClauses_of_aux (n+1) sub sups;
   734 
   735 
   736 fun classrelClauses_of (sub,sups) = 
   737     case sups of [] => [make_axiom_classrelClause 0 sub NONE]
   738 	       | _ => classrelClauses_of_aux 0 sub sups;
   739 
   740 
   741 (***** Isabelle arities *****)
   742 
   743 
   744 fun arity_clause _ (tcons, []) = []
   745   | arity_clause n (tcons, ar::ars) =
   746       make_axiom_arity_clause (tcons,n,ar) :: 
   747       arity_clause (n+1) (tcons,ars);
   748 
   749 fun multi_arity_clause [] = []
   750   | multi_arity_clause (tcon_ar :: tcons_ars)  =
   751       arity_clause 0 tcon_ar  @  multi_arity_clause tcons_ars 
   752 
   753 fun arity_clause_thy thy =
   754   let val arities = #arities (Type.rep_tsig (Sign.tsig_of thy))
   755   in multi_arity_clause (Symtab.dest arities) end;
   756 
   757 
   758 (* Isabelle classes *)
   759 
   760 type classrelClauses = classrelClause list Symtab.table;
   761 
   762 val classrel_of = #2 o #classes o Type.rep_tsig o Sign.tsig_of;
   763 fun classrel_clauses_classrel (C: Sorts.classes) = map classrelClauses_of (Graph.dest C);
   764 val classrel_clauses_thy = List.concat o classrel_clauses_classrel o classrel_of;
   765 
   766 
   767 
   768 (****!!!! Changed for typed equality !!!!****)
   769 
   770 fun wrap_eq_type typ t = eq_typ_wrapper ^"(" ^ t ^ "," ^ typ ^ ")";
   771 
   772 (*Only need to wrap equality's arguments with "typeinfo" if the output clauses are typed 
   773  and if we specifically ask for types to be included.   *)
   774 fun string_of_equality (typ,terms) =
   775       let val [tstr1,tstr2] = map string_of_term terms
   776 	  val typ' = string_of_fol_type typ
   777       in
   778 	  if !keep_types andalso !special_equal 
   779 	  then "equal(" ^ (wrap_eq_type typ' tstr1) ^ "," ^ 
   780 		 	  (wrap_eq_type typ' tstr2) ^ ")"
   781 	  else "equal(" ^ tstr1 ^ "," ^ tstr2 ^ ")"
   782       end
   783 and string_of_term (UVar(x,_)) = x
   784   | string_of_term (Fun("equal",[typ],terms)) = string_of_equality(typ,terms)
   785   | string_of_term (Fun (name,typs,[])) = name (*Overloaded consts like 0 don't get types!*)
   786   | string_of_term (Fun (name,typs,terms)) = 
   787       let val terms_as_strings = map string_of_term terms
   788 	  val typs' = if !keep_types then map string_of_fol_type typs else []
   789       in  name ^ (paren_pack (terms_as_strings @ typs'))  end
   790   | string_of_term _ = error "string_of_term";      
   791 
   792 (* before output the string of the predicate, check if the predicate corresponds to an equality or not. *)
   793 fun string_of_predicate (Predicate("equal",[typ],terms)) = string_of_equality(typ,terms)
   794   | string_of_predicate (Predicate(name,typs,terms)) = 
   795       let val terms_as_strings = map string_of_term terms
   796 	  val typs' = if !keep_types then map string_of_fol_type typs else []
   797       in  name ^ (paren_pack (terms_as_strings @ typs'))  end
   798   | string_of_predicate _ = error "string_of_predicate";      
   799 
   800 
   801 fun string_of_clausename (cls_id,ax_name) = 
   802     clause_prefix ^ ascii_of ax_name ^ "_" ^ Int.toString cls_id;
   803 
   804 fun string_of_type_clsname (cls_id,ax_name,idx) = 
   805     string_of_clausename (cls_id,ax_name) ^ "_tcs" ^ (Int.toString idx);
   806     
   807 
   808 (********************************)
   809 (* Code for producing DFG files *)
   810 (********************************)
   811 
   812 fun dfg_literal (Literal(pol,pred,tag)) =
   813     let val pred_string = string_of_predicate pred
   814     in
   815 	if pol then pred_string else "not(" ^pred_string ^ ")"  
   816     end;
   817 
   818 
   819 (* FIX: what does this mean? *)
   820 (*fun dfg_of_typeLit (LTVar x) = "not(" ^ x ^ ")"
   821   | dfg_of_typeLit (LTFree x) = "(" ^ x ^ ")";*)
   822 
   823 fun dfg_of_typeLit (LTVar x) =  x 
   824   | dfg_of_typeLit (LTFree x) = x ;
   825  
   826 (*Make the string of universal quantifiers for a clause*)
   827 fun forall_open ([],[]) = ""
   828   | forall_open (vars,tvars) = "forall([" ^ (commas (tvars@vars))^ "],\n"
   829 
   830 fun forall_close ([],[]) = ""
   831   | forall_close (vars,tvars) = ")"
   832 
   833 fun gen_dfg_cls (cls_id,ax_name,knd,lits,tvars,vars) = 
   834     "clause( %(" ^ knd ^ ")\n" ^ forall_open(vars,tvars) ^ 
   835     "or(" ^ lits ^ ")" ^ forall_close(vars,tvars) ^ ",\n" ^ 
   836     string_of_clausename (cls_id,ax_name) ^  ").";
   837 
   838 fun gen_dfg_type_cls (cls_id,ax_name,knd,tfree_lit,idx,tvars,vars) = 
   839     "clause( %(" ^ knd ^ ")\n" ^ forall_open(vars,tvars) ^ 
   840     "or( " ^ tfree_lit ^ ")" ^ forall_close(vars,tvars) ^ ",\n" ^ 
   841     string_of_type_clsname (cls_id,ax_name,idx) ^  ").";
   842 
   843 fun dfg_clause_aux (Clause cls) = 
   844   let val lits = map dfg_literal (#literals cls)
   845       val tvar_lits_strs = 
   846 	  if !keep_types then map dfg_of_typeLit (#tvar_type_literals cls) 
   847 	  else []
   848       val tfree_lits =
   849           if !keep_types then map dfg_of_typeLit (#tfree_type_literals cls)
   850           else []
   851   in
   852       (tvar_lits_strs @ lits, tfree_lits)
   853   end; 
   854 
   855 
   856 fun dfg_folterms (Literal(pol,pred,tag)) = 
   857   let val Predicate (predname, _, folterms) = pred
   858   in  folterms  end
   859 
   860  
   861 fun get_uvars (UVar(a,typ)) = [a] 
   862 |   get_uvars (Fun (_,typ,tlist)) = union_all(map get_uvars tlist)
   863 
   864 
   865 fun is_uvar (UVar _) = true
   866 |   is_uvar (Fun _) = false;
   867 
   868 fun uvar_name (UVar(a,_)) = a
   869 |   uvar_name (Fun (a,_,_)) = raise CLAUSE("Not a variable", Const(a,dummyT));
   870 
   871 fun dfg_vars (Clause cls) =
   872     let val lits = #literals cls
   873         val folterms = List.concat (map dfg_folterms lits)
   874     in 
   875         union_all(map get_uvars folterms)
   876     end
   877 
   878 
   879 fun dfg_tvars (Clause cls) =(#tvars cls)
   880 
   881 
   882 	
   883 (* make this return funcs and preds too? *)
   884 fun string_of_predname (Predicate("equal",_,terms)) = "EQUALITY"
   885   | string_of_predname (Predicate(name,_,terms)) = name
   886     
   887 	
   888 
   889 fun concat_with sep []  = ""
   890   | concat_with sep [x] = "(" ^ x ^ ")"
   891   | concat_with sep (x::xs) = "(" ^ x ^ ")" ^  sep ^ (concat_with sep xs);
   892 
   893 fun dfg_pred (Literal(pol,pred,tag)) ax_name = 
   894     (string_of_predname pred) ^ " " ^ ax_name
   895 
   896 fun dfg_clause cls =
   897     let val (lits,tfree_lits) = dfg_clause_aux cls 
   898              (*"lits" includes the typing assumptions (TVars)*)
   899         val vars = dfg_vars cls
   900         val tvars = dfg_tvars cls
   901 	val knd = string_of_kind cls
   902 	val lits_str = commas lits
   903 	val cls_id = get_clause_id cls
   904 	val axname = get_axiomName cls
   905 	val cls_str = gen_dfg_cls(cls_id,axname,knd,lits_str,tvars, vars) 			
   906         fun typ_clss k [] = []
   907           | typ_clss k (tfree :: tfrees) = 
   908               (gen_dfg_type_cls(cls_id,axname,knd,tfree,k, tvars,vars)) :: 
   909               (typ_clss (k+1) tfrees)
   910     in 
   911 	cls_str :: (typ_clss 0 tfree_lits)
   912     end;
   913 
   914 fun string_of_arity (name, num) =  name ^ "," ^ (Int.toString num) 
   915 
   916 fun string_of_preds preds = 
   917   "predicates[" ^ (concat_with ", " (map string_of_arity preds)) ^ "].\n";
   918 
   919 fun string_of_funcs funcs =
   920   "functions[" ^ (concat_with ", " (map string_of_arity funcs)) ^ "].\n" ;
   921 
   922 
   923 fun string_of_symbols predstr funcstr = 
   924   "list_of_symbols.\n" ^ predstr  ^ funcstr  ^ "end_of_list.\n\n";
   925 
   926 
   927 fun string_of_axioms axstr = 
   928   "list_of_clauses(axioms,cnf).\n" ^ axstr ^ "end_of_list.\n\n";
   929 
   930 
   931 fun string_of_conjectures conjstr = 
   932   "list_of_clauses(conjectures,cnf).\n" ^ conjstr ^ "end_of_list.\n\n";
   933 
   934 fun string_of_descrip () = 
   935   "list_of_descriptions.\nname({*[ File     : ],[ Names    :]*}).\nauthor({*[ Source   :]*}).\nstatus(unknown).\ndescription({*[ Refs     :]*}).\nend_of_list.\n\n"
   936 
   937 
   938 fun string_of_start name = "%------------------------------------------------------------------------------\nbegin_problem(" ^ name ^ ").\n\n";
   939 
   940 
   941 fun string_of_end () = "end_problem.\n%------------------------------------------------------------------------------";
   942 
   943 
   944 fun clause2dfg cls =
   945     let val (lits,tfree_lits) = dfg_clause_aux cls 
   946             (*"lits" includes the typing assumptions (TVars)*)
   947 	val cls_id = get_clause_id cls
   948 	val ax_name = get_axiomName cls
   949         val vars = dfg_vars cls
   950         val tvars = dfg_tvars cls
   951         val funcs = funcs_of_cls cls
   952         val preds = preds_of_cls cls
   953 	val knd = string_of_kind cls
   954 	val lits_str = commas lits
   955 	val cls_str = gen_dfg_cls(cls_id,ax_name,knd,lits_str,tvars,vars) 
   956     in
   957 	(cls_str,tfree_lits) 
   958     end;
   959 
   960 
   961 
   962 fun tfree_dfg_clause tfree_lit =
   963   "clause( %(conjecture)\n" ^ "or( " ^ tfree_lit ^ "),\n" ^ "tfree_tcs" ^ ")."
   964 
   965 
   966 fun gen_dfg_file probname axioms conjectures funcs preds = 
   967     let val axstrs_tfrees = (map clause2dfg axioms)
   968 	val (axstrs, atfrees) = ListPair.unzip axstrs_tfrees
   969         val axstr = (space_implode "\n" axstrs) ^ "\n\n"
   970         val conjstrs_tfrees = (map clause2dfg conjectures)
   971 	val (conjstrs, atfrees) = ListPair.unzip conjstrs_tfrees
   972         val tfree_clss = map tfree_dfg_clause (union_all atfrees) 
   973         val conjstr = (space_implode "\n" (tfree_clss@conjstrs)) ^ "\n\n"
   974         val funcstr = string_of_funcs funcs
   975         val predstr = string_of_preds preds
   976     in
   977        (string_of_start probname) ^ (string_of_descrip ()) ^ 
   978        (string_of_symbols funcstr predstr) ^  
   979        (string_of_axioms axstr) ^
   980        (string_of_conjectures conjstr) ^ (string_of_end ())
   981     end;
   982    
   983 fun clauses2dfg [] probname axioms conjectures funcs preds = 
   984       let val funcs' = (union_all(map funcs_of_cls axioms)) @ funcs
   985 	  val preds' = (union_all(map preds_of_cls axioms)) @ preds
   986       in
   987 	 gen_dfg_file probname axioms conjectures funcs' preds' 
   988       end
   989  | clauses2dfg (cls::clss) probname axioms conjectures funcs preds = 
   990      let val (lits,tfree_lits) = dfg_clause_aux cls
   991 	       (*"lits" includes the typing assumptions (TVars)*)
   992 	 val cls_id = get_clause_id cls
   993 	 val ax_name = get_axiomName cls
   994 	 val vars = dfg_vars cls
   995 	 val tvars = dfg_tvars cls
   996 	 val funcs' = (funcs_of_cls cls) union funcs
   997 	 val preds' = (preds_of_cls cls) union preds
   998 	 val knd = string_of_kind cls
   999 	 val lits_str = concat_with ", " lits
  1000 	 val axioms' = if knd = "axiom" then (cls::axioms) else axioms
  1001 	 val conjectures' = 
  1002 	     if knd = "conjecture" then (cls::conjectures) else conjectures
  1003      in
  1004 	 clauses2dfg clss probname axioms' conjectures' funcs' preds' 
  1005      end;
  1006 
  1007 
  1008 fun string_of_arClauseID (ArityClause {clause_id,axiom_name,...}) =
  1009     arclause_prefix ^ ascii_of axiom_name ^ "_" ^ Int.toString clause_id;
  1010 
  1011 fun string_of_arKind (ArityClause arcls) = name_of_kind(#kind arcls);
  1012 
  1013 (*FIXME!!! currently is TPTP format!*)
  1014 fun dfg_of_arLit (TConsLit(b,(c,t,args))) =
  1015       let val pol = if b then "++" else "--"
  1016 	  val arg_strs = paren_pack args
  1017       in 
  1018 	  pol ^ c ^ "(" ^ t ^ arg_strs ^ ")"
  1019       end
  1020   | dfg_of_arLit (TVarLit(b,(c,str))) =
  1021       let val pol = if b then "++" else "--"
  1022       in
  1023 	  pol ^ c ^ "(" ^ str ^ ")"
  1024       end;
  1025     
  1026 
  1027 fun dfg_of_conclLit (ArityClause arcls) = dfg_of_arLit (#conclLit arcls);
  1028      
  1029 
  1030 fun dfg_of_premLits (ArityClause arcls) = map dfg_of_arLit (#premLits arcls);
  1031 		
  1032 
  1033 
  1034 (*FIXME: would this have variables in a forall? *)
  1035 
  1036 fun dfg_arity_clause arcls = 
  1037   let val arcls_id = string_of_arClauseID arcls
  1038       val concl_lit = dfg_of_conclLit arcls
  1039       val prems_lits = dfg_of_premLits arcls
  1040       val knd = string_of_arKind arcls
  1041       val all_lits = concl_lit :: prems_lits
  1042   in
  1043       "clause( %(" ^ knd ^ ")\n" ^  "or( " ^ (bracket_pack all_lits) ^ ")),\n" ^
  1044        arcls_id ^  ")."
  1045   end;
  1046 
  1047 
  1048 (********************************)
  1049 (* code to produce TPTP files   *)
  1050 (********************************)
  1051 
  1052 fun tptp_literal (Literal(pol,pred,tag)) =
  1053     let val pred_string = string_of_predicate pred
  1054 	val tagged_pol = 
  1055 	      if (tag andalso !tagged) then (if pol then "+++" else "---")
  1056 	      else (if pol then "++" else "--")
  1057      in
  1058 	tagged_pol ^ pred_string
  1059     end;
  1060 
  1061 fun tptp_of_typeLit (LTVar x) = "--" ^ x
  1062   | tptp_of_typeLit (LTFree x) = "++" ^ x;
  1063  
  1064 
  1065 fun gen_tptp_cls (cls_id,ax_name,knd,lits) = 
  1066     "input_clause(" ^ string_of_clausename (cls_id,ax_name) ^ "," ^ 
  1067     knd ^ "," ^ lits ^ ").";
  1068 
  1069 fun gen_tptp_type_cls (cls_id,ax_name,knd,tfree_lit,idx) = 
  1070     "input_clause(" ^ string_of_type_clsname (cls_id,ax_name,idx) ^ "," ^ 
  1071     knd ^ ",[" ^ tfree_lit ^ "]).";
  1072 
  1073 fun tptp_type_lits (Clause cls) = 
  1074     let val lits = map tptp_literal (#literals cls)
  1075 	val tvar_lits_strs =
  1076 	      if !keep_types 
  1077 	      then (map tptp_of_typeLit (#tvar_type_literals cls)) 
  1078 	      else []
  1079 	val tfree_lits = 
  1080 	      if !keep_types
  1081 	      then (map tptp_of_typeLit (#tfree_type_literals cls)) 
  1082 	      else []
  1083     in
  1084 	(tvar_lits_strs @ lits, tfree_lits)
  1085     end; 
  1086 
  1087 fun tptp_clause cls =
  1088     let val (lits,tfree_lits) = tptp_type_lits cls 
  1089             (*"lits" includes the typing assumptions (TVars)*)
  1090 	val cls_id = get_clause_id cls
  1091 	val ax_name = get_axiomName cls
  1092 	val knd = string_of_kind cls
  1093 	val lits_str = bracket_pack lits
  1094 	val cls_str = gen_tptp_cls(cls_id,ax_name,knd,lits_str) 			 
  1095 	fun typ_clss k [] = []
  1096           | typ_clss k (tfree :: tfrees) = 
  1097               gen_tptp_type_cls(cls_id,ax_name,knd,tfree,k) :: 
  1098               typ_clss (k+1) tfrees
  1099     in 
  1100 	cls_str :: (typ_clss 0 tfree_lits)
  1101     end;
  1102 
  1103 fun clause2tptp cls =
  1104     let val (lits,tfree_lits) = tptp_type_lits cls 
  1105             (*"lits" includes the typing assumptions (TVars)*)
  1106 	val cls_id = get_clause_id cls
  1107 	val ax_name = get_axiomName cls
  1108 	val knd = string_of_kind cls
  1109 	val lits_str = bracket_pack lits
  1110 	val cls_str = gen_tptp_cls(cls_id,ax_name,knd,lits_str) 
  1111     in
  1112 	(cls_str,tfree_lits) 
  1113     end;
  1114 
  1115 
  1116 fun tfree_clause tfree_lit =
  1117     "input_clause(" ^ "tfree_tcs," ^ "conjecture" ^ ",[" ^ tfree_lit ^ "]).";
  1118 
  1119 
  1120 fun tptp_of_arLit (TConsLit(b,(c,t,args))) =
  1121       let val pol = if b then "++" else "--"
  1122 	  val  arg_strs = paren_pack args
  1123       in 
  1124 	  pol ^ c ^ "(" ^ t ^ arg_strs ^ ")"
  1125       end
  1126   | tptp_of_arLit (TVarLit(b,(c,str))) =
  1127       let val pol = if b then "++" else "--"
  1128       in
  1129 	  pol ^ c ^ "(" ^ str ^ ")"
  1130       end;
  1131     
  1132 
  1133 fun tptp_of_conclLit (ArityClause arcls) = tptp_of_arLit (#conclLit arcls);
  1134      
  1135 fun tptp_of_premLits (ArityClause arcls) = map tptp_of_arLit (#premLits arcls);
  1136 		
  1137 fun tptp_arity_clause arcls = 
  1138     let val arcls_id = string_of_arClauseID arcls
  1139 	val concl_lit = tptp_of_conclLit arcls
  1140 	val prems_lits = tptp_of_premLits arcls
  1141 	val knd = string_of_arKind arcls
  1142 	val all_lits = concl_lit :: prems_lits
  1143     in
  1144 	"input_clause(" ^ arcls_id ^ "," ^ knd ^ "," ^ 
  1145 	(bracket_pack all_lits) ^ ")."
  1146     end;
  1147 
  1148 fun tptp_classrelLits sub sup = 
  1149     let val tvar = "(T)"
  1150     in 
  1151 	case sup of NONE => "[++" ^ sub ^ tvar ^ "]"
  1152 		  | (SOME supcls) =>  "[--" ^ sub ^ tvar ^ ",++" ^ supcls ^ tvar ^ "]"
  1153     end;
  1154 
  1155 
  1156 fun tptp_classrelClause (ClassrelClause {clause_id,subclass,superclass,...}) =
  1157     let val relcls_id = clrelclause_prefix ^ ascii_of subclass ^ "_" ^ 
  1158                         Int.toString clause_id
  1159 	val lits = tptp_classrelLits (make_type_class subclass) 
  1160 	                (Option.map make_type_class superclass)
  1161     in
  1162 	"input_clause(" ^ relcls_id ^ ",axiom," ^ lits ^ ")."
  1163     end; 
  1164 
  1165 end;