src/Provers/blast.ML
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(*  Title: 	Provers/blast
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    ID:         $Id$
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    Author: 	Lawrence C Paulson, Cambridge University Computer Laboratory
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    Copyright   1997  University of Cambridge
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Generic tableau prover with proof reconstruction
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  SKOLEMIZES ReplaceI WRONGLY: allow new vars in prems, or forbid such rules??
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  Needs explicit instantiation of assumptions?
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Blast_tac is often more powerful than fast_tac, but has some limitations.
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Blast_tac...
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  * ignores addss, addbefore, addafter; this restriction is intrinsic
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  * ignores elimination rules that don't have the correct format
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	(conclusion must be a formula variable)
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  * ignores types, which can make HOL proofs fail
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  * rules must not require higher-order unification, e.g. apply_type in ZF
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    + message "Function Var's argument not a bound variable" relates to this
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  * its proof strategy is more general but can actually be slower
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Known problems:
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  "Recursive" chains of rules can sometimes exclude other unsafe formulae
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	from expansion.  This happens because newly-created formulae always
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	have priority over existing ones.  But obviously recursive rules 
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	such as transitivity are treated specially to prevent this.
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  With overloading:
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        Overloading can't follow all chains of type dependencies.  Cannot
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        prove "In1 x ~: Part A In0" because PartE introducees the polymorphic
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	equality In1 x = In0 y, when the corresponding rule uses the (distinct)
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	set equality.  Workaround: supply a type instance of the rule that
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	creates new equalities (e.g. PartE in HOL/ex/Simult)
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	==> affects freeness reasoning about Sexp constants (since they have
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		type ... set)
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  With substition for equalities (hyp_subst_tac):
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        When substitution affects a haz formula or literal, it is moved
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        back to the list of safe formulae.
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        But there's no way of putting it in the right place.  A "moved" or
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        "no DETERM" flag would prevent proofs failing here.
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*)
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(*Should be a type abbreviation?*)
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type netpair = (int*(bool*thm)) Net.net * (int*(bool*thm)) Net.net;
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(*Assumptions about constants:
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  --The negation symbol is "Not"
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  --The equality symbol is "op ="
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  --The is-true judgement symbol is "Trueprop"
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  --There are no constants named "*Goal* or "*False*"
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*)
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signature BLAST_DATA =
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  sig
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  type claset
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  val notE		: thm		(* [| ~P;  P |] ==> R *)
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  val ccontr		: thm		
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  val contr_tac 	: int -> tactic
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  val dup_intr		: thm -> thm
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  val vars_gen_hyp_subst_tac : bool -> int -> tactic
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  val claset		: claset ref
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  val rep_claset	: 
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      claset -> {safeIs: thm list, safeEs: thm list, 
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		 hazIs: thm list, hazEs: thm list,
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		 uwrapper: (int -> tactic) -> (int -> tactic),
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		 swrapper: (int -> tactic) -> (int -> tactic),
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		 safe0_netpair: netpair, safep_netpair: netpair,
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		 haz_netpair: netpair, dup_netpair: netpair}
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  end;
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signature BLAST =
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  sig
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  type claset 
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  datatype term = 
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      Const of string
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    | OConst of string * int
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    | Skolem of string * term option ref list
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    | Free  of string
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    | Var   of term option ref
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    | Bound of int
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    | Abs   of string*term
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    | $  of term*term;
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  type branch
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  val depth_tac 	: claset -> int -> int -> tactic
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  val blast_tac 	: claset -> int -> tactic
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  val Blast_tac 	: int -> tactic
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  val declConsts 	: string list * thm list -> unit
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  (*debugging tools*)
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  val trace	        : bool ref
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  val fullTrace	        : branch list list ref
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  val fromTerm	        : Type.type_sig -> Term.term -> term
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  val fromSubgoal       : Type.type_sig -> Term.term -> term
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  val toTerm	        : int -> term -> Term.term
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  val readGoal          : Sign.sg -> string -> term
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  val tryInThy		: theory -> int -> string ->
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		  (int->tactic) list * branch list list * (int*int*exn) list
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  val trygl		: claset -> int -> int ->
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		  (int->tactic) list * branch list list * (int*int*exn) list
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  val Trygl		: int -> int -> 
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                  (int->tactic) list * branch list list * (int*int*exn) list
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  val normBr		: branch -> branch
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  end;
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functor BlastFun(Data: BLAST_DATA) : BLAST = 
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struct
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type claset = Data.claset;
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val trace = ref false;
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datatype term = 
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    Const of string
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  | OConst of string * int
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  | Skolem of string * term option ref list
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  | Free  of string
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  | Var   of term option ref
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  | Bound of int
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  | Abs   of string*term
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  | op $  of term*term;
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(** Basic syntactic operations **)
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fun is_Var (Var _) = true
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  | is_Var _ = false;
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fun dest_Var (Var x) =  x;
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fun rand (f$x) = x;
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(* maps   (f, [t1,...,tn])  to  f(t1,...,tn) *)
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val list_comb : term * term list -> term = foldl (op $);
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(* maps   f(t1,...,tn)  to  (f, [t1,...,tn]) ; naturally tail-recursive*)
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fun strip_comb u : term * term list = 
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    let fun stripc (f$t, ts) = stripc (f, t::ts)
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        |   stripc  x =  x 
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    in  stripc(u,[])  end;
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(* maps   f(t1,...,tn)  to  f , which is never a combination *)
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fun head_of (f$t) = head_of f
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  | head_of u = u;
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(** Particular constants **)
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fun negate P = Const"Not" $ P;
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fun mkGoal P = Const"*Goal*" $ P;
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fun isGoal (Const"*Goal*" $ _) = true
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  | isGoal _                   = false;
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val Trueprop = Term.Const("Trueprop", Type("o",[])-->propT);
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fun mk_tprop P = Term.$ (Trueprop, P);
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fun isTrueprop (Term.Const("Trueprop",_)) = true
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  | isTrueprop _                          = false;
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(** Dealing with overloaded constants **)
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(*Result is a symbol table, indexed by names of overloaded constants.
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  Each constant maps to a list of (pattern,Blast.Const) pairs.
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  Any Term.Const that matches a pattern gets replaced by the Blast.Const.
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*)
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fun addConsts (t as Term.Const(a,_), tab) =
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     (case Symtab.lookup (tab,a) of
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	  None    => tab  (*ignore: not a constant that we are looking for*)
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	| Some patList => 
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	      (case gen_assoc (op aconv) (patList, t) of
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		  None => Symtab.update
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		           ((a, (t, OConst (a, length patList)) :: patList), 
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			    tab)
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		 | _    => tab))
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  | addConsts (Term.Abs(_,_,body), tab) = addConsts (body, tab)
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  | addConsts (Term.$ (t,u), tab) = addConsts (t, addConsts (u, tab))
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  | addConsts (_,            tab) = tab (*ignore others*);
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fun addRules (rls,tab) = foldr addConsts (map (#prop o rep_thm) rls, tab);
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fun declConst (a,tab) = 
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    case Symtab.lookup (tab,a) of
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	None   => Symtab.update((a,[]), tab)	(*create a brand new entry*)
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      | Some _ => tab				(*preserve old entry*);
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(*maps the name of each overloaded constant to a list of archetypal constants,
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  which may be polymorphic.*)
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local
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val overLoadTab = ref (Symtab.null : (Term.term * term) list Symtab.table)
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    (*The alists in this table should only be increased*)
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in
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fun declConsts (names, rls) =
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    overLoadTab := addRules (rls, foldr declConst (names, !overLoadTab));
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(*Convert a possibly overloaded Term.Const to a Blast.Const*)
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fun fromConst tsig (t as Term.Const (a,_)) =
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  let fun find []                  = Const a
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	| find ((pat,t')::patList) =
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		if Pattern.matches tsig (pat,t) then t' 
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		else find patList
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  in  case Symtab.lookup(!overLoadTab, a) of
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	   None         => Const a
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	 | Some patList => find patList
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  end;
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end;
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(*Tests whether 2 terms are alpha-convertible; chases instantiations*)
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fun (Const a)      aconv (Const b)      = a=b
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  | (OConst ai)    aconv (OConst bj)    = ai=bj
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  | (Skolem (a,_)) aconv (Skolem (b,_)) = a=b  (*arglists must then be equal*)
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  | (Free a)       aconv (Free b)       = a=b
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  | (Var(ref(Some t))) aconv u          = t aconv u
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  | t aconv (Var(ref(Some u)))          = t aconv u
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  | (Var v)        aconv (Var w)        = v=w	(*both Vars are un-assigned*)
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  | (Bound i)      aconv (Bound j)      = i=j
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  | (Abs(_,t))     aconv (Abs(_,u))     = t aconv u
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  | (f$t)          aconv (g$u)          = (f aconv g) andalso (t aconv u)
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  | _ aconv _  =  false;
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fun mem_term (_, [])     = false
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  | mem_term (t, t'::ts) = t aconv t' orelse mem_term(t,ts);
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fun ins_term(t,ts) = if mem_term(t,ts) then ts else t :: ts;
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fun mem_var (v: term option ref, []) = false
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  | mem_var (v, v'::vs)              = v=v' orelse mem_var(v,vs);
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fun ins_var(v,vs) = if mem_var(v,vs) then vs else v :: vs;
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(** Vars **)
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(*Accumulates the Vars in the term, suppressing duplicates*)
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fun add_term_vars (Skolem(a,args),	vars) = add_vars_vars(args,vars)
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  | add_term_vars (Var (v as ref None),	vars) = ins_var (v, vars)
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  | add_term_vars (Var (ref (Some u)), vars)  = add_term_vars(u,vars)
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  | add_term_vars (Abs (_,body),	vars) = add_term_vars(body,vars)
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  | add_term_vars (f$t,	vars) =  add_term_vars (f, add_term_vars(t, vars))
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  | add_term_vars (_,	vars) = vars
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(*Term list version.  [The fold functionals are slow]*)
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and add_terms_vars ([],    vars) = vars
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  | add_terms_vars (t::ts, vars) = add_terms_vars (ts, add_term_vars(t,vars))
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(*Var list version.*)
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and add_vars_vars ([],    vars) = vars
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  | add_vars_vars (ref (Some u) :: vs, vars) = 
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	add_vars_vars (vs, add_term_vars(u,vars))
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  | add_vars_vars (v::vs, vars) =   (*v must be a ref None*)
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	add_vars_vars (vs, ins_var (v, vars));
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(*Chase assignments in "vars"; return a list of unassigned variables*)
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fun vars_in_vars vars = add_vars_vars(vars,[]);
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(*increment a term's non-local bound variables
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     inc is  increment for bound variables
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     lev is  level at which a bound variable is considered 'loose'*)
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fun incr_bv (inc, lev, u as Bound i) = if i>=lev then Bound(i+inc) else u 
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  | incr_bv (inc, lev, Abs(a,body)) = Abs(a, incr_bv(inc,lev+1,body))
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  | incr_bv (inc, lev, f$t) = incr_bv(inc,lev,f) $ incr_bv(inc,lev,t)
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  | incr_bv (inc, lev, u) = u;
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fun incr_boundvars  0  t = t
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  | incr_boundvars inc t = incr_bv(inc,0,t);
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(*Accumulate all 'loose' bound vars referring to level 'lev' or beyond.
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   (Bound 0) is loose at level 0 *)
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fun add_loose_bnos (Bound i, lev, js)   = if i<lev then js  
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					  else  (i-lev) ins_int js
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  | add_loose_bnos (Abs (_,t), lev, js) = add_loose_bnos (t, lev+1, js)
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  | add_loose_bnos (f$t, lev, js)       =
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	        add_loose_bnos (f, lev, add_loose_bnos (t, lev, js)) 
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  | add_loose_bnos (_, _, js)           = js;
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fun loose_bnos t = add_loose_bnos (t, 0, []);
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fun subst_bound (arg, t) : term = 
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  let fun subst (t as Bound i, lev) =
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 	    if i<lev then  t    (*var is locally bound*)
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	    else  if i=lev then incr_boundvars lev arg
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		           else Bound(i-1)  (*loose: change it*)
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	| subst (Abs(a,body), lev) = Abs(a, subst(body,lev+1))
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	| subst (f$t, lev) =  subst(f,lev)  $  subst(t,lev)
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	| subst (t,lev)    = t
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  in  subst (t,0)  end;
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(*Normalize, INCLUDING bodies of abstractions--this might be slow?*)
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fun norm t = case t of
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    Skolem (a,args)      => Skolem(a, vars_in_vars args)
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  | (Var (ref None))     => t
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  | (Var (ref (Some u))) => norm u
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  | (f $ u) => (case norm f of
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		    Abs(_,body) => norm (subst_bound (u, body))
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		  | nf => nf $ norm u)
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  | Abs (a,body) => Abs (a, norm body)
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  | _ => t;
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   313
f03b1652fc6a Implementation of blast_tac: fast tableau prover
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   314
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   315
(*Weak (one-level) normalize for use in unification*)
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fun wkNormAux t = case t of
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   317
    (Var v) => (case !v of
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   318
		    Some u => wkNorm u
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   319
		  | None   => t)
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   320
  | (f $ u) => (case wkNormAux f of
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   321
		    Abs(_,body) => wkNorm (subst_bound (u, body))
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		  | nf          => nf $ u)
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parents: 2924
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   323
  | Abs (a,body) =>	(*eta-contract if possible*)
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   324
	(case wkNormAux body of
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   325
	     nb as (f $ t) => 
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parents: 2924
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   326
		 if (0 mem_int loose_bnos f) orelse wkNorm t <> Bound 0
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parents: 2924
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   327
		 then Abs(a,nb)
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parents: 2924
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   328
		 else wkNorm (incr_boundvars ~1 f)
3092
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parents: 3083
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   329
	   | nb => Abs (a,nb))
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   330
  | _ => t
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paulson
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   331
and wkNorm t = case head_of t of
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   332
    Const _        => t
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   333
  | OConst _       => t
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paulson
parents:
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   334
  | Skolem(a,args) => t
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   335
  | Free _         => t
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paulson
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   336
  | _              => wkNormAux t;
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parents:
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   337
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
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   338
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
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   339
(*Does variable v occur in u?  For unification.*)
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   340
fun varOccur v = 
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   341
  let fun occL [] = false	(*same as (exists occ), but faster*)
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   342
	| occL (u::us) = occ u orelse occL us
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   343
      and occ (Var w) = 
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	      v=w orelse
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   345
              (case !w of None   => false
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   346
	                | Some u => occ u)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
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   347
        | occ (Skolem(_,args)) = occL (map Var args)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
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   348
        | occ (Abs(_,u)) = occ u
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paulson
parents:
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   349
        | occ (f$u)      = occ u  orelse  occ f
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   350
        | occ (_)        = false;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
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   351
  in  occ  end;
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   352
f03b1652fc6a Implementation of blast_tac: fast tableau prover
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   353
exception UNIFY;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
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parents:
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   354
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
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   355
val trail = ref [] : term option ref list ref;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
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   356
val ntrail = ref 0;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   357
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   358
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
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   359
(*Restore the trail to some previous state: for backtracking*)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
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   360
fun clearTo n =
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paulson
parents: 3049
diff changeset
   361
    while !ntrail<>n do
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
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   362
	(hd(!trail) := None;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
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   363
	 trail := tl (!trail);
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   364
	 ntrail := !ntrail - 1);
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   365
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   366
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
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   367
(*First-order unification with bound variables.  
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
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   368
  "vars" is a list of variables local to the rule and NOT to be put
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
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   369
	on the trail (no point in doing so)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
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   370
*)
2999
fad7cc426242 Penalty for branching instantiations reduced from log3 to log4.
paulson
parents: 2952
diff changeset
   371
fun unify(allowClash,vars,t,u) =
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
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   372
    let val n = !ntrail 
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
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   373
	fun update (t as Var v, u) =
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
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   374
	    if t aconv u then ()
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
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   375
	    else if varOccur v u then raise UNIFY 
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
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   376
	    else if mem_var(v, vars) then v := Some u
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
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   377
		 else (*avoid updating Vars in the branch if possible!*)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
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   378
		      if is_Var u andalso mem_var(dest_Var u, vars)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   379
		      then dest_Var u := Some t
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   380
		      else (v := Some u;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   381
			    trail := v :: !trail;  ntrail := !ntrail + 1)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   382
	fun unifyAux (t,u) = 
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   383
	    case (wkNorm t,  wkNorm u) of
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   384
		(nt as Var v,  nu) => update(nt,nu)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   385
	      | (nu,  nt as Var v) => update(nt,nu)
2999
fad7cc426242 Penalty for branching instantiations reduced from log3 to log4.
paulson
parents: 2952
diff changeset
   386
	      | (Const a, OConst(b,_))  => if allowClash andalso a=b then ()
fad7cc426242 Penalty for branching instantiations reduced from log3 to log4.
paulson
parents: 2952
diff changeset
   387
		                           else raise UNIFY
fad7cc426242 Penalty for branching instantiations reduced from log3 to log4.
paulson
parents: 2952
diff changeset
   388
	      | (OConst(a,_), Const b)  => if allowClash andalso a=b then ()
fad7cc426242 Penalty for branching instantiations reduced from log3 to log4.
paulson
parents: 2952
diff changeset
   389
		                           else raise UNIFY
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   390
	      | (Abs(_,t'),  Abs(_,u')) => unifyAux(t',u')
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   391
		    (*NB: can yield unifiers having dangling Bound vars!*)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   392
	      | (f$t',  g$u') => (unifyAux(f,g); unifyAux(t',u'))
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   393
	      | (nt,  nu)    => if nt aconv nu then () else raise UNIFY
3083
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   394
    in  (unifyAux(t,u); true) handle UNIFY => (clearTo n; false)
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   395
    end;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   396
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   397
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   398
(*Convert from "real" terms to prototerms; eta-contract*)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   399
fun fromTerm tsig t =
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   400
  let val alist = ref []
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   401
      fun from (t as Term.Const _) = fromConst tsig t
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   402
	| from (Term.Free  (a,_)) = Free a
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   403
	| from (Term.Bound i)     = Bound i
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   404
	| from (Term.Var (ixn,T)) = 
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   405
	      (case (assoc_string_int(!alist,ixn)) of
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   406
		   None => let val t' = Var(ref None)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   407
		           in  alist := (ixn, (t', T)) :: !alist;  t'
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   408
			   end
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   409
		 | Some (v,_) => v)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   410
	| from (Term.Abs (a,_,u)) = 
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   411
	      (case  from u  of
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   412
		u' as (f $ Bound 0) => 
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   413
		  if (0 mem_int loose_bnos f) then Abs(a,u')
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   414
		  else incr_boundvars ~1 f 
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   415
	      | u' => Abs(a,u'))
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   416
	| from (Term.$ (f,u)) = from f $ from u
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   417
  in  from t  end;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   418
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   419
(* A1==>...An==>B  goes to  [A1,...,An], where B is not an implication *)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   420
fun strip_imp_prems (Const"==>" $ (Const"Trueprop" $ A) $ B) = 
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   421
           A :: strip_imp_prems B
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   422
  | strip_imp_prems (Const"==>" $ A $ B) = A :: strip_imp_prems B
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   423
  | strip_imp_prems _ = [];
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   424
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   425
(* A1==>...An==>B  goes to B, where B is not an implication *)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   426
fun strip_imp_concl (Const"==>" $ A $ B) = strip_imp_concl B
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   427
  | strip_imp_concl (Const"Trueprop" $ A) = A
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   428
  | strip_imp_concl A = A : term;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   429
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   430
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   431
(*** Conversion of Elimination Rules to Tableau Operations ***)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   432
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   433
(*The conclusion becomes the goal/negated assumption *False*: delete it!*)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   434
fun squash_nots [] = []
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   435
  | squash_nots (Const "*Goal*" $ (Var (ref (Some (Const"*False*")))) :: Ps) =
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   436
	squash_nots Ps
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   437
  | squash_nots (Const "Not" $ (Var (ref (Some (Const"*False*")))) :: Ps) =
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   438
	squash_nots Ps
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   439
  | squash_nots (P::Ps) = P :: squash_nots Ps;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   440
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   441
fun skoPrem vars (Const "all" $ Abs (_, P)) =
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   442
        skoPrem vars (subst_bound (Skolem (gensym "S_", vars), P))
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   443
  | skoPrem vars P = P;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   444
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   445
fun convertPrem t = 
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   446
    squash_nots (mkGoal (strip_imp_concl t) :: strip_imp_prems t);
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   447
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   448
(*Expects elimination rules to have a formula variable as conclusion*)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   449
fun convertRule vars t =
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   450
  let val (P::Ps) = strip_imp_prems t
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   451
      val Var v   = strip_imp_concl t
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   452
  in  v := Some (Const"*False*");
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   453
      (P, map (convertPrem o skoPrem vars) Ps) 
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   454
  end;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   455
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   456
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   457
(*Like dup_elim, but puts the duplicated major premise FIRST*)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   458
fun rev_dup_elim th = th RSN (2, revcut_rl) |> assumption 2 |> Sequence.hd;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   459
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   460
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   461
(*Count new hyps so that they can be rotated*)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   462
fun nNewHyps []                         = 0
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   463
  | nNewHyps (Const "*Goal*" $ _ :: Ps) = nNewHyps Ps
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   464
  | nNewHyps (P::Ps)                    = 1 + nNewHyps Ps;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   465
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   466
fun rot_subgoals_tac [] i st      = Sequence.single st
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   467
  | rot_subgoals_tac (k::ks) i st =
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   468
      rot_subgoals_tac ks (i+1) (Sequence.hd (rotate_tac (~k) i st))
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   469
      handle OPTION _ => Sequence.null;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   470
2999
fad7cc426242 Penalty for branching instantiations reduced from log3 to log4.
paulson
parents: 2952
diff changeset
   471
fun TRACE rl tac st i = if !trace then (prth rl; tac st i) else tac st i;
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   472
3083
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   473
local open General in  (*make available the Basis type "option"*)
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   474
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   475
(*Tableau rule from elimination rule.  Flag "dup" requests duplication of the
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   476
  affected formula.*)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   477
fun fromRule vars rl = 
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   478
  let val {tsig,...} = Sign.rep_sg (#sign (rep_thm rl))
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   479
      val trl = rl |> rep_thm |> #prop |> fromTerm tsig |> convertRule vars
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   480
      fun tac dup i = 
2999
fad7cc426242 Penalty for branching instantiations reduced from log3 to log4.
paulson
parents: 2952
diff changeset
   481
	  TRACE rl (etac (if dup then rev_dup_elim rl else rl)) i
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   482
	  THEN rot_subgoals_tac (map nNewHyps (#2 trl)) i
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   483
	  
3049
79c1ba7effb2 refer to SOME, NONE on top-level;
wenzelm
parents: 3030
diff changeset
   484
  in SOME (trl, tac) end
2924
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
   485
  handle Bind => (*reject: conclusion is not just a variable*)
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
   486
   (if !trace then (writeln"Warning: ignoring ill-formed elimination rule";
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
   487
		    print_thm rl)
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
   488
    else ();
3049
79c1ba7effb2 refer to SOME, NONE on top-level;
wenzelm
parents: 3030
diff changeset
   489
    NONE);
3083
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   490
end;
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   491
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   492
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   493
(*** Conversion of Introduction Rules (needed for efficiency in 
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   494
               proof reconstruction) ***)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   495
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   496
fun convertIntrPrem t = mkGoal (strip_imp_concl t) :: strip_imp_prems t;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   497
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   498
fun convertIntrRule vars t =
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   499
  let val Ps = strip_imp_prems t
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   500
      val P  = strip_imp_concl t
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   501
  in  (mkGoal P, map (convertIntrPrem o skoPrem vars) Ps) 
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   502
  end;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   503
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   504
(*Tableau rule from introduction rule.  Since haz rules are now delayed, 
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   505
  "dup" is always FALSE for introduction rules.*)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   506
fun fromIntrRule vars rl = 
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   507
  let val {tsig,...} = Sign.rep_sg (#sign (rep_thm rl))
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   508
      val trl = rl |> rep_thm |> #prop |> fromTerm tsig |> convertIntrRule vars
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   509
      fun tac dup i = 
2999
fad7cc426242 Penalty for branching instantiations reduced from log3 to log4.
paulson
parents: 2952
diff changeset
   510
	  TRACE rl (DETERM o (rtac (if dup then Data.dup_intr rl else rl))) i
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   511
	  THEN rot_subgoals_tac (map nNewHyps (#2 trl)) i
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   512
  in (trl, tac) end;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   513
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   514
3030
04e3359921a8 Addition of printed tracing. Also some tidying
paulson
parents: 3021
diff changeset
   515
val dummyVar = Term.Var (("etc",0), dummyT);
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   516
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   517
(*Convert from prototerms to ordinary terms with dummy types
2924
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
   518
  Ignore abstractions; identify all Vars; STOP at given depth*)
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
   519
fun toTerm 0 _             = dummyVar
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
   520
  | toTerm d (Const a)     = Term.Const (a,dummyT)
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
   521
  | toTerm d (OConst(a,_)) = Term.Const (a,dummyT)
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
   522
  | toTerm d (Skolem(a,_)) = Term.Const (a,dummyT)
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
   523
  | toTerm d (Free a)      = Term.Free  (a,dummyT)
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
   524
  | toTerm d (Bound i)     = Term.Bound i
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
   525
  | toTerm d (Var _)       = dummyVar
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
   526
  | toTerm d (Abs(a,_))    = dummyVar
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
   527
  | toTerm d (f $ u)       = Term.$ (toTerm d f, toTerm (d-1) u);
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   528
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   529
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   530
fun netMkRules P vars (nps: netpair list) =
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   531
  case P of
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   532
      (Const "*Goal*" $ G) =>
2924
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
   533
	let val pG = mk_tprop (toTerm 2 G)
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   534
	    val intrs = List.concat 
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   535
		             (map (fn (inet,_) => Net.unify_term inet pG) 
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   536
			      nps)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   537
	in  map (fromIntrRule vars o #2) (orderlist intrs)  end
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   538
    | _ =>
2924
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
   539
	let val pP = mk_tprop (toTerm 3 P)
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   540
	    val elims = List.concat 
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   541
		             (map (fn (_,enet) => Net.unify_term enet pP) 
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   542
			      nps)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   543
	in  List.mapPartial (fromRule vars o #2) (orderlist elims)  end;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   544
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   545
(**
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   546
end;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   547
**)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   548
3092
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   549
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   550
(*Pending formulae carry md (may duplicate) flags*)
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   551
type branch = ((term*bool) list *	(*safe formulae on this level*)
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   552
               (term*bool) list) list * (*haz formulae  on this level*)
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   553
	      term list *               (*literals: irreducible formulae*)
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   554
	      term option ref list *    (*variables occurring in branch*)
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   555
	      int;                      (*resource limit*)
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   556
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   557
val fullTrace = ref[] : branch list list ref;
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   558
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   559
(*Normalize a branch--for tracing*)
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   560
fun norm2 (G,md) = (norm G, md);
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   561
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   562
fun normLev (Gs,Hs) = (map norm2 Gs, map norm2 Hs);
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   563
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   564
fun normBr (br, lits, vars, lim) =
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   565
     (map normLev br, map norm lits, vars, lim);
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   566
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   567
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   568
val dummyVar2 = Term.Var(("var",0), dummyT);
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   569
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   570
(*Convert from prototerms to ordinary terms with dummy types for tracing*)
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   571
fun showTerm d (Const a)     = Term.Const (a,dummyT)
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   572
  | showTerm d (OConst(a,_)) = Term.Const (a,dummyT)
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   573
  | showTerm d (Skolem(a,_)) = Term.Const (a,dummyT)
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   574
  | showTerm d (Free a)      = Term.Free  (a,dummyT)
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   575
  | showTerm d (Bound i)     = Term.Bound i
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   576
  | showTerm d (Var _)       = dummyVar2
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   577
  | showTerm d (Abs(a,t))    = if d=0 then dummyVar
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   578
			       else Term.Abs(a, dummyT, showTerm (d-1) t)
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   579
  | showTerm d (f $ u)       = if d=0 then dummyVar
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   580
			       else Term.$ (showTerm d f, showTerm (d-1) u);
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   581
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   582
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   583
fun traceTerm sign t = Sign.string_of_term sign (showTerm 8 (norm t));
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   584
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   585
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   586
(*Print tracing information at each iteration of prover*)
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   587
fun tracing sign brs = 
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   588
  let fun printPairs (((G,_)::_,_)::_)  = prs(traceTerm sign G)
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   589
	| printPairs (([],(H,_)::_)::_) = prs(traceTerm sign H ^ "\t (Unsafe)")
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   590
	| printPairs _                 = ()
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   591
      fun printBrs (brs0 as (pairs, lits, _, lim) :: brs) =
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   592
	    (fullTrace := brs0 :: !fullTrace;
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   593
	     seq (fn _ => prs "+") brs;
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   594
	     prs (" [" ^ Int.toString lim ^ "] ");
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   595
	     printPairs pairs;
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   596
	     writeln"")
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   597
  in if !trace then printBrs (map normBr brs) else ()
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   598
  end;
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   599
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   600
(*Tracing: variables updated in the last branch operation?*)
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   601
fun traceVars ntrl =
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   602
    if !trace then 
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   603
       (case !ntrail-ntrl of
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   604
	    0 => writeln""
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   605
	  | 1 => writeln"\t1 variable updated"
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   606
	  | n => writeln("\t" ^ Int.toString n ^ " variables updated"))
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   607
    else ();
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   608
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   609
(*Tracing: how many new branches are created?*)
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   610
fun traceNew prems =
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   611
    if !trace then 
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   612
        case length prems of
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   613
	    0 => prs"branch closed by rule"
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   614
	  | 1 => prs"branch extended (1 new subgoal)"
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   615
	  | n => prs("branch split: "^ Int.toString n ^ " new subgoals")
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   616
    else ();
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   617
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   618
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   619
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   620
(*** Code for handling equality: naive substitution, like hyp_subst_tac ***)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   621
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   622
(*Replace the ATOMIC term "old" by "new" in t*)  
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   623
fun subst_atomic (old,new) t =
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   624
    let fun subst (Var(ref(Some u))) = subst u
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   625
	  | subst (Abs(a,body))      = Abs(a, subst body)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   626
	  | subst (f$t)              = subst f $ subst t
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   627
	  | subst t                  = if t aconv old then new else t
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   628
    in  subst t  end;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   629
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   630
(*Eta-contract a term from outside: just enough to reduce it to an atom*)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   631
fun eta_contract_atom (t0 as Abs(a, body)) = 
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   632
      (case  eta_contract2 body  of
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   633
        f $ Bound 0 => if (0 mem_int loose_bnos f) then t0
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   634
		       else eta_contract_atom (incr_boundvars ~1 f)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   635
      | _ => t0)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   636
  | eta_contract_atom t = t
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   637
and eta_contract2 (f$t) = f $ eta_contract_atom t
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   638
  | eta_contract2 t     = eta_contract_atom t;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   639
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   640
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   641
(*When can we safely delete the equality?
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   642
    Not if it equates two constants; consider 0=1.
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   643
    Not if it resembles x=t[x], since substitution does not eliminate x.
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   644
    Not if it resembles ?x=0; another goal could instantiate ?x to Suc(i)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   645
  Prefer to eliminate Bound variables if possible.
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   646
  Result:  true = use as is,  false = reorient first *)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   647
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   648
(*Does t occur in u?  For substitution.  
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   649
  Does NOT check args of Skolem terms: substitution does not affect them.
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   650
  NOT reflexive since hyp_subst_tac fails on x=x.*)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   651
fun substOccur t = 
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   652
  let fun occEq u = (t aconv u) orelse occ u
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   653
      and occ (Var(ref None))    = false
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   654
	| occ (Var(ref(Some u))) = occEq u
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   655
        | occ (Abs(_,u))         = occEq u
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   656
        | occ (f$u)              = occEq u  orelse  occEq f
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   657
        | occ (_)                = false;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   658
  in  occEq  end;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   659
3092
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   660
exception DEST_EQ;
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   661
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   662
(*Take apart an equality (plain or overloaded).  NO constant Trueprop*)
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   663
fun dest_eq (Const  "op ="     $ t $ u) = 
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   664
		(eta_contract_atom t, eta_contract_atom u)
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   665
  | dest_eq (OConst("op =",_)  $ t $ u) = 
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   666
		(eta_contract_atom t, eta_contract_atom u)
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   667
  | dest_eq _                           = raise DEST_EQ;
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   668
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   669
fun check (t,u,v) = if substOccur t u then raise DEST_EQ else v;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   670
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   671
(*IF the goal is an equality with a substitutable variable 
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   672
  THEN orient that equality ELSE raise exception DEST_EQ*)
3092
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   673
fun orientGoal (t,u) = case (t,u) of
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   674
       (Skolem _, _) => check(t,u,(t,u))	(*eliminates t*)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   675
     | (_, Skolem _) => check(u,t,(u,t))	(*eliminates u*)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   676
     | (Free _, _)   => check(t,u,(t,u))	(*eliminates t*)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   677
     | (_, Free _)   => check(u,t,(u,t))	(*eliminates u*)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   678
     | _             => raise DEST_EQ;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   679
2894
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   680
(*Substitute through the branch if an equality goal (else raise DEST_EQ).
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   681
  Moves affected literals back into the branch, but it is not clear where
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   682
  they should go: this could make proofs fail.  ??? *)
3092
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   683
fun equalSubst sign (G, pairs, lits, vars, lim) = 
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   684
  let val (t,u) = orientGoal(dest_eq G)
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   685
      val subst = subst_atomic (t,u)
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   686
      fun subst2(G,md) = (subst G, md)
2924
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
   687
      (*substitute throughout Haz list; move affected ones to Safe part*)
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
   688
      fun subHazs ([], Gs, nHs)         = (Gs,nHs)
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
   689
	| subHazs ((H,md)::Hs, Gs, nHs) =
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
   690
	    let val nH = subst H
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
   691
	    in  if nH aconv H then subHazs (Hs, Gs, (H,md)::nHs)
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
   692
		              else subHazs (Hs, (nH,md)::Gs, nHs)
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
   693
            end
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
   694
      val pairs' = map (fn(Gs,Hs) => subHazs(rev Hs, map subst2 Gs, [])) pairs
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
   695
      (*substitute throughout literals; move affected ones to Safe part*)
2894
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   696
      fun subLits ([], [], nlits) =          (pairs', nlits, vars, lim)
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   697
	| subLits ([], Gs, nlits) = ((Gs,[])::pairs', nlits, vars, lim)
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   698
	| subLits (lit::lits, Gs, nlits) =
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   699
	    let val nlit = subst lit
2894
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   700
	    in  if nlit aconv lit then subLits (lits, Gs, nlit::nlits)
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   701
		                  else subLits (lits, (nlit,true)::Gs, nlits)
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   702
            end
3092
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   703
  in  if !trace then writeln ("Substituting " ^ traceTerm sign u ^
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   704
			      " for " ^ traceTerm sign t ^ " in branch" )
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   705
      else ();
3083
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   706
      subLits (rev lits, [], [])  
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   707
  end;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   708
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   709
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   710
exception NEWBRANCHES and CLOSEF;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   711
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   712
exception PROVE;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   713
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   714
val eq_contr_tac = eresolve_tac [Data.notE]  THEN'  eq_assume_tac;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   715
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   716
val eContr_tac  = TRACE Data.notE (eq_contr_tac ORELSE' Data.contr_tac);
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   717
val eAssume_tac = TRACE asm_rl   (eq_assume_tac ORELSE' assume_tac);
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   718
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   719
(*Try to unify complementary literals and return the corresponding tactic. *) 
3083
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   720
fun tryClose (Const"*Goal*" $ G,  L) = 
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   721
	if unify(true,[],G,L) then Some eAssume_tac else None
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   722
  | tryClose (G,  Const"*Goal*" $ L) = 
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   723
	if unify(true,[],G,L) then Some eAssume_tac else None
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   724
  | tryClose (Const"Not" $ G,  L)    = 
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   725
	if unify(true,[],G,L) then Some eContr_tac else None
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   726
  | tryClose (G,  Const"Not" $ L)    = 
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   727
	if unify(true,[],G,L) then Some eContr_tac else None
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   728
  | tryClose _                       = None;
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   729
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   730
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   731
(*Were there Skolem terms in the premise?  Must NOT chase Vars*)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   732
fun hasSkolem (Skolem _)     = true
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   733
  | hasSkolem (Abs (_,body)) = hasSkolem body 
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   734
  | hasSkolem (f$t)          =  hasSkolem f orelse hasSkolem t
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   735
  | hasSkolem _              = false;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   736
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   737
(*Attach the right "may duplicate" flag to new formulae: if they contain
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   738
  Skolem terms then allow duplication.*)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   739
fun joinMd md [] = []
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   740
  | joinMd md (G::Gs) = (G, hasSkolem G orelse md) :: joinMd md Gs;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   741
2894
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   742
(*Convert a Goal to an ordinary Not.  Used also in dup_intr, where a goal like
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   743
  Ex(P) is duplicated as the assumption ~Ex(P). *)
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   744
fun negOfGoal (Const"*Goal*" $ G) = negate G
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   745
  | negOfGoal G                   = G;
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   746
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   747
fun negOfGoal2 (G,md) = (negOfGoal G, md);
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   748
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   749
(*Converts all Goals to Nots in the safe parts of a branch.  They could
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   750
  have been moved there from the literals list after substitution (equalSubst).
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   751
  There can be at most one--this function could be made more efficient.*)
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   752
fun negOfGoals pairs = map (fn (Gs,haz) => (map negOfGoal2 Gs, haz)) pairs;
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   753
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   754
(*Tactic.  Convert *Goal* to negated assumption in FIRST position*)
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   755
val negOfGoal_tac = rtac Data.ccontr THEN' rotate_tac ~1;
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   756
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   757
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   758
(** Backtracking and Pruning **)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   759
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   760
(*clashVar vars (n,trail) determines whether any of the last n elements
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   761
  of "trail" occur in "vars" OR in their instantiations*)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   762
fun clashVar [] = (fn _ => false)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   763
  | clashVar vars =
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   764
      let fun clash (0, _)     = false
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   765
	    | clash (_, [])    = false
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   766
	    | clash (n, v::vs) = exists (varOccur v) vars orelse clash(n-1,vs)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   767
      in  clash  end;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   768
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   769
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   770
(*nbrs = # of branches just prior to closing this one.  Delete choice points
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   771
  for goals proved by the latest inference, provided NO variables in the
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   772
  next branch have been updated.*)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   773
fun prune (1, nxtVars, choices) = choices  (*DON'T prune at very end: allow 
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   774
					     backtracking over bad proofs*)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   775
  | prune (nbrs, nxtVars, choices) =
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   776
      let fun traceIt last =
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   777
		let val ll = length last
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   778
		    and lc = length choices
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   779
		in if !trace andalso ll<lc then
3083
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   780
		    (writeln("Pruning " ^ Int.toString(lc-ll) ^ " levels"); 
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   781
		     last)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   782
		   else last
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   783
		end
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   784
	  fun pruneAux (last, _, _, []) = last
3083
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   785
	    | pruneAux (last, ntrl, trl, (ntrl',nbrs',exn) :: choices) =
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   786
		if nbrs' < nbrs 
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   787
		then last  (*don't backtrack beyond first solution of goal*)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   788
		else if nbrs' > nbrs then pruneAux (last, ntrl, trl, choices)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   789
		else (* nbrs'=nbrs *)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   790
		     if clashVar nxtVars (ntrl-ntrl', trl) then last
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   791
		     else (*no clashes: can go back at least this far!*)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   792
			  pruneAux(choices, ntrl', List.drop(trl, ntrl-ntrl'), 
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   793
				   choices)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   794
  in  traceIt (pruneAux (choices, !ntrail, !trail, choices))  end;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   795
2894
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   796
fun nextVars ((br, lits, vars, lim) :: _) = map Var vars
3083
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   797
  | nextVars []                           = [];
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   798
3083
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   799
fun backtrack (choices as (ntrl, nbrs, exn)::_) = 
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   800
      (if !trace then (writeln ("Backtracking; now there are " ^ 
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   801
				Int.toString nbrs ^ " branches"))
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   802
                 else (); 
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   803
       raise exn)
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   804
  | backtrack _ = raise PROVE;
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   805
2894
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   806
(*Add the literal G, handling *Goal* and detecting duplicates.*)
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   807
fun addLit (Const "*Goal*" $ G, lits) = 
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   808
      (*New literal is a *Goal*, so change all other Goals to Nots*)
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   809
      let fun bad (Const"*Goal*" $ _) = true
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   810
	    | bad (Const"Not" $ G')   = G aconv G'
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   811
	    | bad _                   = false;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   812
	  fun change [] = []
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   813
	    | change (Const"*Goal*" $ G' :: lits) = 
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   814
		  if G aconv G' then change lits
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   815
		  else Const"Not" $ G' :: change lits
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   816
	    | change (Const"Not" $ G' :: lits)    = 
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   817
		  if G aconv G' then change lits
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   818
		  else Const"Not" $ G' :: change lits
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   819
	    | change (lit::lits) = lit :: change lits
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   820
      in
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   821
	Const "*Goal*" $ G :: (if exists bad lits then change lits else lits)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   822
      end
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   823
  | addLit (G,lits) = ins_term(G, lits)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   824
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   825
2952
ea834e8fac1b Changed penalty from log2 to log3
paulson
parents: 2924
diff changeset
   826
(*For calculating the "penalty" to assess on a branching factor of n
ea834e8fac1b Changed penalty from log2 to log3
paulson
parents: 2924
diff changeset
   827
  log2 seems a little too severe*)
3083
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   828
fun log n = if n<4 then 0 else 1 + log(n div 4);
2924
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
   829
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
   830
3021
39806db47be9 Loop detection: before expanding a haz formula, see whether it is a duplicate
paulson
parents: 2999
diff changeset
   831
(*match(t,u) says whether the term u might be an instance of the pattern t
39806db47be9 Loop detection: before expanding a haz formula, see whether it is a duplicate
paulson
parents: 2999
diff changeset
   832
  Used to detect "recursive" rules such as transitivity*)
39806db47be9 Loop detection: before expanding a haz formula, see whether it is a duplicate
paulson
parents: 2999
diff changeset
   833
fun match (Var _) u   = true
39806db47be9 Loop detection: before expanding a haz formula, see whether it is a duplicate
paulson
parents: 2999
diff changeset
   834
  | match (Const"*Goal*") (Const"Not") = true
39806db47be9 Loop detection: before expanding a haz formula, see whether it is a duplicate
paulson
parents: 2999
diff changeset
   835
  | match (Const"Not") (Const"*Goal*") = true
39806db47be9 Loop detection: before expanding a haz formula, see whether it is a duplicate
paulson
parents: 2999
diff changeset
   836
  | match (Const a) (Const b) = (a=b)
39806db47be9 Loop detection: before expanding a haz formula, see whether it is a duplicate
paulson
parents: 2999
diff changeset
   837
  | match (OConst ai) (OConst bj) = (ai=bj)
39806db47be9 Loop detection: before expanding a haz formula, see whether it is a duplicate
paulson
parents: 2999
diff changeset
   838
  | match (Free a) (Free b) = (a=b)
39806db47be9 Loop detection: before expanding a haz formula, see whether it is a duplicate
paulson
parents: 2999
diff changeset
   839
  | match (Bound i) (Bound j) = (i=j)
39806db47be9 Loop detection: before expanding a haz formula, see whether it is a duplicate
paulson
parents: 2999
diff changeset
   840
  | match (Abs(_,t)) (Abs(_,u)) = match t u
39806db47be9 Loop detection: before expanding a haz formula, see whether it is a duplicate
paulson
parents: 2999
diff changeset
   841
  | match (f$t) (g$u) = match f g andalso match t u
39806db47be9 Loop detection: before expanding a haz formula, see whether it is a duplicate
paulson
parents: 2999
diff changeset
   842
  | match t u   = false;
39806db47be9 Loop detection: before expanding a haz formula, see whether it is a duplicate
paulson
parents: 2999
diff changeset
   843
39806db47be9 Loop detection: before expanding a haz formula, see whether it is a duplicate
paulson
parents: 2999
diff changeset
   844
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   845
(*Tableau prover based on leanTaP.  Argument is a list of branches.  Each 
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   846
  branch contains a list of unexpanded formulae, a list of literals, and a 
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   847
  bound on unsafe expansions.*)
3030
04e3359921a8 Addition of printed tracing. Also some tidying
paulson
parents: 3021
diff changeset
   848
fun prove (sign, cs, brs, cont) =
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   849
 let val {safe0_netpair, safep_netpair, haz_netpair, ...} = Data.rep_claset cs
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   850
     val safeList = [safe0_netpair, safep_netpair]
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   851
     and hazList  = [haz_netpair]
3083
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   852
     fun prv (tacs, trs, choices, []) = cont (tacs, trs, choices)
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   853
       | prv (tacs, trs, choices, 
2894
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   854
	      brs0 as (((G,md)::br, haz)::pairs, lits, vars, lim) :: brs) =
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   855
	  let exception PRV (*backtrack to precisely this recursion!*)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   856
	      val ntrl = !ntrail 
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   857
	      val nbrs = length brs0
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   858
              val nxtVars = nextVars brs
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   859
	      val G = norm G
2924
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
   860
	      val rules = netMkRules G vars safeList
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   861
	      (*Make a new branch, decrementing "lim" if instantiations occur*)
2894
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   862
	      fun newBr (vars',lim') prems =
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   863
		  map (fn prem => 
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   864
		       if (exists isGoal prem) 
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   865
		       then (((joinMd md prem, []) :: 
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   866
			      negOfGoals ((br, haz)::pairs)),
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   867
			     map negOfGoal lits, 
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   868
			     vars', lim') 
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   869
		       else (((joinMd md prem, []) :: (br, haz) :: pairs),
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   870
			     lits, vars', lim'))
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   871
		  prems @
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   872
		  brs		  
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   873
	      (*Seek a matching rule.  If unifiable then add new premises
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   874
                to branch.*)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   875
	      fun deeper [] = raise NEWBRANCHES
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   876
		| deeper (((P,prems),tac)::grls) =
3083
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   877
		    if unify(false, add_term_vars(P,[]), P, G) 
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   878
		    then  (*P comes from the rule; G comes from the branch.*)
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   879
		     let val ntrl' = !ntrail
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   880
			 val lim' = if ntrl < !ntrail 
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   881
				    then lim - (1+log(length rules))
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   882
				    else lim   (*discourage branching updates*)
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   883
			 val vars  = vars_in_vars vars
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   884
			 val vars' = foldr add_terms_vars (prems, vars)
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   885
			 val choices' = (ntrl, nbrs, PRV) :: choices
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   886
			 val tacs' = (DETERM o (tac false)) :: tacs 
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   887
					 (*no duplication*)
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   888
		     in
3092
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   889
			 traceNew prems;  traceVars ntrl;
3083
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   890
			 (if null prems then (*closed the branch: prune!*)
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   891
			    prv(tacs',  brs0::trs, 
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   892
				prune (nbrs, nxtVars, choices'),
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   893
				brs)
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   894
			  else
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   895
			  if lim'<0 (*faster to kill ALL the alternatives*)
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   896
			  then raise NEWBRANCHES
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   897
			  else
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   898
			    prv(tacs',  brs0::trs, choices',
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   899
				newBr (vars',lim') prems))
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   900
                         handle PRV => 
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   901
			   if ntrl < ntrl' (*Vars have been updated*)
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   902
			      then
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   903
				(*Backtrack at this level.
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   904
				  Reset Vars and try another rule*)
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   905
				(clearTo ntrl;  deeper grls)
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   906
			   else (*backtrack to previous level*)
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   907
				backtrack choices
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   908
		     end
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   909
		    else deeper grls
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   910
	      (*Try to close branch by unifying with head goal*)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   911
	      fun closeF [] = raise CLOSEF
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   912
		| closeF (L::Ls) = 
3083
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   913
		    case tryClose(G,L) of
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   914
			None     => closeF Ls
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   915
		      | Some tac => 
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   916
			    let val choices' = 
3092
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   917
				    (if !trace then (prs"branch closed";
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   918
						     traceVars ntrl)
3083
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   919
				               else ();
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   920
				     prune (nbrs, nxtVars, 
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   921
					    (ntrl, nbrs, PRV) :: choices))
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   922
			    in  prv (tac::tacs, brs0::trs, choices', brs)  
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   923
				handle PRV => 
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   924
				    (*reset Vars and try another literal
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   925
				      [this handler is pruned if possible!]*)
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   926
				 (clearTo ntrl;  closeF Ls)
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   927
			    end
2894
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   928
	      fun closeFl [] = raise CLOSEF
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   929
		| closeFl ((br, haz)::pairs) =
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   930
		    closeF (map fst br)
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   931
		      handle CLOSEF => closeF (map fst haz)
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   932
			handle CLOSEF => closeFl pairs
3083
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   933
	  in tracing sign brs0; 
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   934
	     if lim<0 then backtrack choices
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   935
	     else
3092
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   936
	     prv ((TRY  o  Data.vars_gen_hyp_subst_tac false)  ::  tacs, 
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   937
		  (*The TRY above allows the substitution to fail, e.g. if
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   938
		    the real version is z = f(?x z).  Rest of proof might
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   939
		    still succeed!*)
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   940
		  brs0::trs,  choices,
3092
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   941
		  equalSubst sign (G, (br,haz)::pairs, lits, vars, lim) :: brs)
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   942
	     handle DEST_EQ => closeF lits
2894
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   943
	      handle CLOSEF => closeFl ((br,haz)::pairs)
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   944
	        handle CLOSEF => 
2924
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
   945
		 deeper rules
2894
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   946
		  handle NEWBRANCHES => 
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   947
		   (case netMkRules G vars hazList of
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   948
		       [] => (*no plausible rules: move G to literals*)
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   949
			   prv (tacs, brs0::trs, choices,
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   950
				((br,haz)::pairs, addLit(G,lits), vars, lim)
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   951
				::brs)
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   952
		    | _ => (*G admits some haz rules: try later*)
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   953
			   prv (if isGoal G then negOfGoal_tac :: tacs
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   954
				else tacs, 
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   955
				brs0::trs,  choices,
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   956
				((br, haz@[(negOfGoal G, md)])::pairs,
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   957
				 lits, vars, lim)  ::  brs))
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   958
	  end
2924
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
   959
       | prv (tacs, trs, choices, 
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
   960
	      (([],haz)::(Gs,haz')::pairs, lits, vars, lim) :: brs) =
2894
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   961
	     (*no more "safe" formulae: transfer haz down a level*)
2924
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
   962
	   prv (tacs, trs, choices, 
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
   963
		((Gs,haz@haz')::pairs, lits, vars, lim) :: brs)
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   964
       | prv (tacs, trs, choices, 
2894
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   965
	      brs0 as ([([], (H,md)::Hs)], lits, vars, lim) :: brs) =
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   966
   	     (*no safe steps possible at any level: apply a haz rule*)
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   967
	  let exception PRV (*backtrack to precisely this recursion!*)
2894
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   968
	      val H = norm H
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   969
	      val ntrl = !ntrail
2924
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
   970
	      val rules = netMkRules H vars hazList
3021
39806db47be9 Loop detection: before expanding a haz formula, see whether it is a duplicate
paulson
parents: 2999
diff changeset
   971
	      (*new premises of haz rules may NOT be duplicated*)
39806db47be9 Loop detection: before expanding a haz formula, see whether it is a duplicate
paulson
parents: 2999
diff changeset
   972
	      fun newPrem (vars,recur,dup,lim') prem = 
39806db47be9 Loop detection: before expanding a haz formula, see whether it is a duplicate
paulson
parents: 2999
diff changeset
   973
		  let val Gs' = map (fn P => (P,false)) prem
39806db47be9 Loop detection: before expanding a haz formula, see whether it is a duplicate
paulson
parents: 2999
diff changeset
   974
		      and Hs' = if dup then Hs @ [(negOfGoal H, md)] else Hs
39806db47be9 Loop detection: before expanding a haz formula, see whether it is a duplicate
paulson
parents: 2999
diff changeset
   975
                  in  (if recur then [(Gs',Hs')] else [(Gs',[]), ([],Hs')], 
39806db47be9 Loop detection: before expanding a haz formula, see whether it is a duplicate
paulson
parents: 2999
diff changeset
   976
		       lits, vars, lim')
39806db47be9 Loop detection: before expanding a haz formula, see whether it is a duplicate
paulson
parents: 2999
diff changeset
   977
		  end
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   978
	      fun newBr x prems = map (newPrem x) prems  @  brs
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   979
	      (*Seek a matching rule.  If unifiable then add new premises
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   980
                to branch.*)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   981
	      fun deeper [] = raise NEWBRANCHES
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   982
		| deeper (((P,prems),tac)::grls) =
3083
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   983
		    if unify(false, add_term_vars(P,[]), P, H)
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   984
		    then
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   985
		     let val ntrl' = !ntrail
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   986
			 val vars  = vars_in_vars vars
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   987
			 val vars' = foldr add_terms_vars (prems, vars)
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   988
			    (*duplicate H if md and the subgoal has new vars*)
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   989
			 val dup = md andalso vars' <> vars
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   990
			     (*any instances of P in the subgoals?*)
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   991
			 and recur = exists (exists (match P)) prems
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   992
			 val lim' = (*Decrement "lim" extra if updates occur*)
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   993
			     if ntrl < !ntrail then lim - (1+log(length rules))
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   994
			     else lim-1 
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   995
				 (*It is tempting to leave "lim" UNCHANGED if
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   996
				   both dup and recur are false.  Proofs are
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   997
				   found at shallower depths, but looping
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   998
				   occurs too often...*)
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   999
			 val mayUndo = not(null grls)   (*other rules to try?*)
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1000
				     orelse ntrl < ntrl' (*variables updated?*)
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1001
				     orelse vars=vars'   (*no new Vars?*)
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1002
			 val tac' = if mayUndo then tac dup
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1003
				    else DETERM o (tac dup) 
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1004
		     in
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1005
		       if lim'<0 andalso not (null prems)
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1006
		       then (*it's faster to kill ALL the alternatives*)
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1007
			   raise NEWBRANCHES
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1008
		       else 
3092
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
  1009
			 traceNew prems;  traceVars ntrl;
3083
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1010
			 prv(tac dup :: tacs, 
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1011
			     brs0::trs, 
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1012
			     (ntrl, length brs0, PRV) :: choices, 
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1013
			     newBr (vars', recur, dup, lim') prems)
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1014
			  handle PRV => 
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1015
			      if mayUndo
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1016
			      then (*reset Vars and try another rule*)
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1017
				   (clearTo ntrl;  deeper grls)
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1018
			      else (*backtrack to previous level*)
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1019
				   backtrack choices
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1020
		     end
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1021
		    else deeper grls
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1022
	  in tracing sign brs0; 
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1023
	     if lim<1 then backtrack choices
2924
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
  1024
	     else deeper rules
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1025
	     handle NEWBRANCHES => 
2894
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
  1026
		 (*cannot close branch: move H to literals*)
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1027
		 prv (tacs,  brs0::trs,  choices,
2894
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
  1028
		      ([([], Hs)], H::lits, vars, lim)::brs)
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1029
	  end
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1030
       | prv (tacs, trs, choices, _ :: brs) = backtrack choices
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1031
 in prv ([], [], [(!ntrail, length brs, PROVE)], brs) end;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1032
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1033
2883
fd1c0b8e9b61 Now exports declConsts!
paulson
parents: 2854
diff changeset
  1034
(*Construct an initial branch.*)
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1035
fun initBranch (ts,lim) = 
2894
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
  1036
    ([(map (fn t => (t,true)) ts, [])],
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
  1037
     [], add_terms_vars (ts,[]), lim);
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1038
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1039
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1040
(*** Conversion & Skolemization of the Isabelle proof state ***)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1041
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1042
(*Make a list of all the parameters in a subgoal, even if nested*)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1043
local open Term 
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1044
in
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1045
fun discard_foralls (Const("all",_)$Abs(a,T,t)) = discard_foralls t
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1046
  | discard_foralls t = t;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1047
end;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1048
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1049
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1050
(*List of variables not appearing as arguments to the given parameter*)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1051
fun getVars []                  i = []
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1052
  | getVars ((_,(v,is))::alist) i =
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1053
	if i mem is then getVars alist i
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1054
	else v :: getVars alist i;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1055
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1056
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1057
(*Conversion of a subgoal: Skolemize all parameters*)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1058
fun fromSubgoal tsig t =
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1059
  let val alist = ref []
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1060
      fun hdvar ((ix,(v,is))::_) = v
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1061
      fun from lev t =
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1062
	let val (ht,ts) = Term.strip_comb t
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1063
	    fun apply u = list_comb (u, map (from lev) ts)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1064
	    fun bounds [] = []
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1065
	      | bounds (Term.Bound i::ts) = 
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1066
		  if i<lev then error"Function Var's argument not a parameter"
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1067
		  else i-lev :: bounds ts
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1068
	      | bounds ts = error"Function Var's argument not a bound variable"
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1069
        in
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1070
	  case ht of 
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1071
	      t as Term.Const _ => apply (fromConst tsig t)	    
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1072
	    | Term.Free  (a,_) => apply (Free a)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1073
	    | Term.Bound i     => apply (Bound i)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1074
	    | Term.Var (ix,_) => 
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1075
		  (case (assoc_string_int(!alist,ix)) of
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1076
		       None => (alist := (ix, (ref None, bounds ts))
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1077
					  :: !alist;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1078
				Var (hdvar(!alist)))
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1079
		     | Some(v,is) => if is=bounds ts then Var v
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1080
			    else error("Discrepancy among occurrences of ?"
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1081
				       ^ Syntax.string_of_vname ix))
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1082
	    | Term.Abs (a,_,body) => 
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1083
		  if null ts then Abs(a, from (lev+1) body)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1084
		  else error "fromSubgoal: argument not in normal form"
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1085
        end
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1086
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1087
      val npars = length (Logic.strip_params t)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1088
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1089
      (*Skolemize a subgoal from a proof state*)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1090
      fun skoSubgoal i t =
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1091
	  if i<npars then 
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1092
	      skoSubgoal (i+1)
3092
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
  1093
		(subst_bound (Skolem (gensym "T_", getVars (!alist) i), 
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1094
			      t))
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1095
	  else t
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1096
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1097
  in  skoSubgoal 0 (from 0 (discard_foralls t))  end;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1098
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1099
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1100
(*Tactic using tableau engine and proof reconstruction.  
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1101
 "lim" is depth limit.*)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1102
fun depth_tac cs lim i st = 
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1103
    (fullTrace:=[];  trail := [];  ntrail := 0;
3030
04e3359921a8 Addition of printed tracing. Also some tidying
paulson
parents: 3021
diff changeset
  1104
     let val {sign,...} = rep_thm st
04e3359921a8 Addition of printed tracing. Also some tidying
paulson
parents: 3021
diff changeset
  1105
	 val {tsig,...} = Sign.rep_sg sign
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1106
	 val skoprem = fromSubgoal tsig (List.nth(prems_of st, i-1))
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1107
         val hyps  = strip_imp_prems skoprem
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1108
         and concl = strip_imp_concl skoprem
3083
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1109
         fun cont (tacs,_,choices) = 
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1110
	     (case Sequence.pull(EVERY' (rev tacs) i st) of
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1111
		  None => (writeln ("PROOF FAILED for depth " ^
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1112
				    Int.toString lim);
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1113
			   backtrack choices)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1114
		| cell => Sequence.seqof(fn()=> cell))
3030
04e3359921a8 Addition of printed tracing. Also some tidying
paulson
parents: 3021
diff changeset
  1115
     in prove (sign, cs, [initBranch (mkGoal concl :: hyps, lim)], cont)
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1116
     end
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1117
     handle Subscript => Sequence.null
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1118
	  | PROVE     => Sequence.null);
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1119
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1120
fun blast_tac cs = (DEEPEN (1,20) (depth_tac cs) 0);
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1121
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1122
fun Blast_tac i = blast_tac (!Data.claset) i;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1123
2924
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
  1124
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
  1125
(*** For debugging: these apply the prover to a subgoal and return 
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
  1126
     the resulting tactics, trace, etc.                            ***)
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
  1127
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
  1128
(*Translate subgoal i from a proof state*)
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
  1129
fun trygl cs lim i = 
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
  1130
    (fullTrace:=[];  trail := [];  ntrail := 0;
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
  1131
     let val st = topthm()
3030
04e3359921a8 Addition of printed tracing. Also some tidying
paulson
parents: 3021
diff changeset
  1132
         val {sign,...} = rep_thm st
04e3359921a8 Addition of printed tracing. Also some tidying
paulson
parents: 3021
diff changeset
  1133
	 val {tsig,...} = Sign.rep_sg sign
2924
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
  1134
	 val skoprem = fromSubgoal tsig (List.nth(prems_of st, i-1))
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
  1135
         val hyps  = strip_imp_prems skoprem
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
  1136
         and concl = strip_imp_concl skoprem
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
  1137
     in timeap prove
3030
04e3359921a8 Addition of printed tracing. Also some tidying
paulson
parents: 3021
diff changeset
  1138
	 (sign, cs, [initBranch (mkGoal concl :: hyps, lim)], I)
2924
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
  1139
     end
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
  1140
     handle Subscript => error("There is no subgoal " ^ Int.toString i));
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
  1141
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
  1142
fun Trygl lim i = trygl (!Data.claset) lim i;
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
  1143
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
  1144
(*Read a string to make an initial, singleton branch*)
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
  1145
fun readGoal sign s = read_cterm sign (s,propT) |>
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
  1146
                      term_of |> fromTerm (#tsig(Sign.rep_sg sign)) |> 
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
  1147
		      rand |> mkGoal;
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
  1148
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
  1149
fun tryInThy thy lim s = 
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
  1150
    (fullTrace:=[];  trail := [];  ntrail := 0;
3030
04e3359921a8 Addition of printed tracing. Also some tidying
paulson
parents: 3021
diff changeset
  1151
     timeap prove (sign_of thy, 
04e3359921a8 Addition of printed tracing. Also some tidying
paulson
parents: 3021
diff changeset
  1152
		   !Data.claset, 
2924
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
  1153
		   [initBranch ([readGoal (sign_of thy) s], lim)], 
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
  1154
		   I));
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
  1155
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
  1156
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1157
end;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1158