src/Provers/blast.ML
author paulson
Fri, 16 Feb 2001 13:29:07 +0100
changeset 11152 32d002362005
parent 11119 2d92ab19747b
child 11754 3928d990c22f
permissions -rw-r--r--
Blast bug fix: now always duplicates when applying a haz rule, whether or not new variables are added. Can now prove theorems such as these: val prems = Goal "[|P==>Q; P==>~Q|] ==> ~P"; by (blast_tac (claset() addDs prems) 1); val prems = Goal "[|Q==>P; ~Q==>P|] ==> P"; by (blast_tac (claset() addIs prems) 1);
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(*  Title: 	Provers/blast.ML
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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 wrappers (addss, addbefore, addafter, addWrapper, ...); 
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    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.  Sometimes
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	the formulae get into the wrong order (see WRONG below).
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  With overloading:
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        Calls to Blast.overloaded (see HOL/Set.ML for examples) are needed
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	to tell Blast_tac when to retain some type information.  Make sure
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	you know the constant's internal name, which might be "op <=" or 
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	"Relation.op ^^".
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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 hyp_subst_tac     : bool ref -> int -> tactic
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  val claset		: unit -> claset
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  val rep_cs	: (* dependent on classical.ML *)
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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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		 xtraIs: thm list, xtraEs: thm list,
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		 swrappers: (string * wrapper) list, 
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		 uwrappers: (string * wrapper) list,
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		 safe0_netpair: netpair, safep_netpair: netpair,
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		 haz_netpair: netpair, dup_netpair: netpair, xtra_netpair: netpair}
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  val atomize: thm list
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  val cla_modifiers: (Args.T list -> (Method.modifier * Args.T list)) list
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  val cla_meth': (claset -> int -> tactic) -> thm list -> Proof.context -> Proof.method
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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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  exception TRANS of string    (*reports translation errors*)
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  datatype term = 
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      Const of string
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    | TConst of string * term
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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 overloaded 	: string * (Term.typ -> Term.typ) -> unit
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  val get_overloads	: unit -> (string * (Term.typ -> Term.typ)) list
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  val setup		: (theory -> theory) list
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  (*debugging tools*)
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  val stats	        : bool ref
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  val trace	        : bool ref
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  val fullTrace	        : branch list list ref
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  val fromType	        : (indexname * term) list ref -> Term.typ -> term
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  val fromTerm	        : Term.term -> term
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  val fromSubgoal       : Term.term -> term
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  val instVars          : term -> (unit -> unit)
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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 atomize_goal = Method.atomize_goal Data.atomize;
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val trace = ref false
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and stats = ref false;   (*for runtime and search statistics*)
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datatype term = 
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    Const  of string
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  | TConst of string * term    (*type of overloaded constant--as a term!*)
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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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(*alist is a map from TVar names to Vars.  We need to unify the TVars
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  faithfully in order to track overloading*)
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fun fromType alist (Term.Type(a,Ts)) = list_comb (Const a, 
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						  map (fromType alist) Ts)
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  | fromType alist (Term.TFree(a,_)) = Free a
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  | fromType alist (Term.TVar (ixn,_)) =
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	      (case (assoc_string_int(!alist,ixn)) of
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		   None => let val t' = Var(ref None)
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		           in  alist := (ixn, t') :: !alist;  t'
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			   end
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		 | Some v => v)
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local
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val overloads = ref ([]: (string * (Term.typ -> Term.typ)) list)
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in
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fun overloaded arg = (overloads := arg :: (!overloads));
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fun get_overloads() = !overloads;
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(*Convert a possibly overloaded Term.Const to a Blast.Const or Blast.TConst,
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  converting its type to a Blast.term in the latter case.*)
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fun fromConst alist (a,T) =
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  case assoc_string (!overloads, a) of
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      None   => Const a		(*not overloaded*)
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    | Some f => 
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	let val T' = f T
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		     handle Match => error
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                ("Blast_tac: unexpected type for overloaded constant " ^ a)
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        in  TConst(a, fromType alist T')  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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  | (TConst (a,ta)) aconv (TConst (b,tb)) = a=b andalso ta aconv tb
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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 (TConst (_,t),	vars) = add_term_vars(t,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...but not the bodies of ABSTRACTIONS*)
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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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  | TConst(a,aT)         => TConst(a, norm aT)
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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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  | _ => t;
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(*Weak (one-level) normalize for use in unification*)
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fun wkNormAux t = case t of
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    (Var v) => (case !v of
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		    Some u => wkNorm u
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		  | None   => t)
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  | (f $ u) => (case wkNormAux f of
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		    Abs(_,body) => wkNorm (subst_bound (u, body))
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		  | nf          => nf $ u)
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  | Abs (a,body) =>	(*eta-contract if possible*)
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	(case wkNormAux body of
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	     nb as (f $ t) => 
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		 if (0 mem_int loose_bnos f) orelse wkNorm t <> Bound 0
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   323
		 then Abs(a,nb)
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   324
		 else wkNorm (incr_boundvars ~1 f)
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	   | nb => Abs (a,nb))
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  | _ => t
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and wkNorm t = case head_of t of
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    Const _        => t
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  | TConst _       => t
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  | Skolem(a,args) => t
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  | Free _         => t
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  | _              => wkNormAux t;
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   333
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   334
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   335
(*Does variable v occur in u?  For unification.  
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  Dangling bound vars are also forbidden.*)
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fun varOccur v = 
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  let fun occL lev [] = false	(*same as (exists occ), but faster*)
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	| occL lev (u::us) = occ lev u orelse occL lev us
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      and occ lev (Var w) = 
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	      v=w orelse
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              (case !w of None   => false
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	                | Some u => occ lev u)
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        | occ lev (Skolem(_,args)) = occL lev (map Var args)
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            (*ignore TConst, since term variables can't occur in types (?) *)
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        | occ lev (Bound i)  = lev <= i
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        | occ lev (Abs(_,u)) = occ (lev+1) u
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        | occ lev (f$u)      = occ lev u  orelse  occ lev f
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        | occ lev _          = false;
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   350
  in  occ 0  end;
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   351
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   352
exception UNIFY;
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   353
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   354
val trail = ref [] : term option ref list ref;
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   355
val ntrail = ref 0;
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   356
f03b1652fc6a Implementation of blast_tac: fast tableau prover
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   357
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   358
(*Restore the trail to some previous state: for backtracking*)
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   359
fun clearTo n =
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   360
    while !ntrail<>n do
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   361
	(hd(!trail) := None;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
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   362
	 trail := tl (!trail);
f03b1652fc6a Implementation of blast_tac: fast tableau prover
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   363
	 ntrail := !ntrail - 1);
f03b1652fc6a Implementation of blast_tac: fast tableau prover
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   364
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   365
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   366
(*First-order unification with bound variables.  
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   367
  "vars" is a list of variables local to the rule and NOT to be put
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   368
	on the trail (no point in doing so)
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   369
*)
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   370
fun unify(vars,t,u) =
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   371
    let val n = !ntrail 
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   372
	fun update (t as Var v, u) =
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   373
	    if t aconv u then ()
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   374
	    else if varOccur v u then raise UNIFY 
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   375
	    else if mem_var(v, vars) then v := Some u
f03b1652fc6a Implementation of blast_tac: fast tableau prover
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   376
		 else (*avoid updating Vars in the branch if possible!*)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
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   377
		      if is_Var u andalso mem_var(dest_Var u, vars)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
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   378
		      then dest_Var u := Some t
f03b1652fc6a Implementation of blast_tac: fast tableau prover
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   379
		      else (v := Some u;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
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   380
			    trail := v :: !trail;  ntrail := !ntrail + 1)
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   381
	fun unifyAux (t,u) = 
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   382
	    case (wkNorm t,  wkNorm u) of
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   383
		(nt as Var v,  nu) => update(nt,nu)
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   384
	      | (nu,  nt as Var v) => update(nt,nu)
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   385
	      | (TConst(a,at), TConst(b,bt)) => if a=b then unifyAux(at,bt)
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   386
		                                else raise UNIFY
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f03b1652fc6a Implementation of blast_tac: fast tableau prover
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   387
	      | (Abs(_,t'),  Abs(_,u')) => unifyAux(t',u')
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   388
		    (*NB: can yield unifiers having dangling Bound vars!*)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
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   389
	      | (f$t',  g$u') => (unifyAux(f,g); unifyAux(t',u'))
f03b1652fc6a Implementation of blast_tac: fast tableau prover
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   390
	      | (nt,  nu)    => if nt aconv nu then () else raise UNIFY
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   391
    in  (unifyAux(t,u); true) handle UNIFY => (clearTo n; false)
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   392
    end;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
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   393
f03b1652fc6a Implementation of blast_tac: fast tableau prover
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   394
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   395
(*Convert from "real" terms to prototerms; eta-contract
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   396
  Code is duplicated with fromSubgoal.  Correct this?*)
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   397
fun fromTerm t =
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   398
  let val alistVar = ref []
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   399
      and alistTVar = ref []
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   400
      fun from (Term.Const aT) = fromConst alistTVar aT
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
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   401
	| from (Term.Free  (a,_)) = Free a
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
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   402
	| from (Term.Bound i)     = Bound i
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
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   403
	| from (Term.Var (ixn,T)) = 
4065
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   404
	      (case (assoc_string_int(!alistVar,ixn)) of
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
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   405
		   None => let val t' = Var(ref None)
4065
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   406
		           in  alistVar := (ixn, t') :: !alistVar;  t'
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
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diff changeset
   407
			   end
4065
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   408
		 | Some v => v)
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
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   409
	| from (Term.Abs (a,_,u)) = 
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   410
	      (case  from u  of
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   411
		u' as (f $ Bound 0) => 
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   412
		  if (0 mem_int loose_bnos f) then Abs(a,u')
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   413
		  else incr_boundvars ~1 f 
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   414
	      | u' => Abs(a,u'))
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   415
	| from (Term.$ (f,u)) = from f $ from u
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
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   416
  in  from t  end;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   417
4065
8862fcb5d44a New treatment of overloading\!
paulson
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diff changeset
   418
(*A debugging function: replaces all Vars by dummy Frees for visual inspection
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paulson
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   419
  of whether they are distinct.  Function revert undoes the assignments.*)
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paulson
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   420
fun instVars t =
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diff changeset
   421
  let val name = ref "A"
8862fcb5d44a New treatment of overloading\!
paulson
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diff changeset
   422
      val updated = ref []
8862fcb5d44a New treatment of overloading\!
paulson
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diff changeset
   423
      fun inst (TConst(a,t)) = inst t
8862fcb5d44a New treatment of overloading\!
paulson
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diff changeset
   424
	| inst (Var(v as ref None)) = (updated := v :: (!updated);
8862fcb5d44a New treatment of overloading\!
paulson
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diff changeset
   425
				       v       := Some (Free ("?" ^ !name)); 
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   426
				       name    := bump_string (!name))
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   427
	| inst (Abs(a,t))    = inst t
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   428
	| inst (f $ u)       = (inst f; inst u)
8862fcb5d44a New treatment of overloading\!
paulson
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diff changeset
   429
	| inst _             = ()
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   430
      fun revert() = seq (fn v => v:=None) (!updated)
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   431
  in  inst t; revert  end;
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   432
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   433
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   434
(* 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
   435
fun strip_imp_prems (Const"==>" $ (Const"Trueprop" $ A) $ B) = 
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   436
           A :: strip_imp_prems B
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   437
  | strip_imp_prems (Const"==>" $ A $ B) = A :: strip_imp_prems B
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   438
  | strip_imp_prems _ = [];
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   439
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   440
(* A1==>...An==>B  goes to B, where B is not an implication *)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   441
fun strip_imp_concl (Const"==>" $ A $ B) = strip_imp_concl B
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   442
  | strip_imp_concl (Const"Trueprop" $ A) = A
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   443
  | strip_imp_concl A = A : term;
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
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   446
(*** Conversion of Elimination Rules to Tableau Operations ***)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   447
9170
0bfe5354d5e7 warns of weak elim rules and ignores them
paulson
parents: 7607
diff changeset
   448
exception ElimBadConcl and ElimBadPrem;
0bfe5354d5e7 warns of weak elim rules and ignores them
paulson
parents: 7607
diff changeset
   449
0bfe5354d5e7 warns of weak elim rules and ignores them
paulson
parents: 7607
diff changeset
   450
(*The conclusion becomes the goal/negated assumption *False*: delete it!
0bfe5354d5e7 warns of weak elim rules and ignores them
paulson
parents: 7607
diff changeset
   451
  If we don't find it then the premise is ill-formed and could cause 
0bfe5354d5e7 warns of weak elim rules and ignores them
paulson
parents: 7607
diff changeset
   452
  PROOF FAILED*)
0bfe5354d5e7 warns of weak elim rules and ignores them
paulson
parents: 7607
diff changeset
   453
fun delete_concl [] = raise ElimBadPrem
0bfe5354d5e7 warns of weak elim rules and ignores them
paulson
parents: 7607
diff changeset
   454
  | delete_concl (Const "*Goal*" $ (Var (ref (Some (Const"*False*")))) :: Ps) =
0bfe5354d5e7 warns of weak elim rules and ignores them
paulson
parents: 7607
diff changeset
   455
	Ps
0bfe5354d5e7 warns of weak elim rules and ignores them
paulson
parents: 7607
diff changeset
   456
  | delete_concl (Const "Not" $ (Var (ref (Some (Const"*False*")))) :: Ps) =
0bfe5354d5e7 warns of weak elim rules and ignores them
paulson
parents: 7607
diff changeset
   457
	Ps
0bfe5354d5e7 warns of weak elim rules and ignores them
paulson
parents: 7607
diff changeset
   458
  | delete_concl (P::Ps) = P :: delete_concl Ps;
2854
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
fun skoPrem vars (Const "all" $ Abs (_, P)) =
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   461
        skoPrem vars (subst_bound (Skolem (gensym "S_", vars), P))
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   462
  | skoPrem vars P = P;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   463
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   464
fun convertPrem t = 
9170
0bfe5354d5e7 warns of weak elim rules and ignores them
paulson
parents: 7607
diff changeset
   465
    delete_concl (mkGoal (strip_imp_concl t) :: strip_imp_prems t);
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   466
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   467
(*Expects elimination rules to have a formula variable as conclusion*)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   468
fun convertRule vars t =
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   469
  let val (P::Ps) = strip_imp_prems t
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   470
      val Var v   = strip_imp_concl t
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   471
  in  v := Some (Const"*False*");
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   472
      (P, map (convertPrem o skoPrem vars) Ps) 
9170
0bfe5354d5e7 warns of weak elim rules and ignores them
paulson
parents: 7607
diff changeset
   473
  end
0bfe5354d5e7 warns of weak elim rules and ignores them
paulson
parents: 7607
diff changeset
   474
  handle Bind => raise ElimBadConcl;
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   475
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   476
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   477
(*Like dup_elim, but puts the duplicated major premise FIRST*)
4271
3a82492e70c5 changed Pure/Sequence interface -- isatool fixseq;
wenzelm
parents: 4240
diff changeset
   478
fun rev_dup_elim th = th RSN (2, revcut_rl) |> assumption 2 |> Seq.hd;
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   479
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   480
4391
cc3e8453d7f0 More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents: 4354
diff changeset
   481
(*Rotate the assumptions in all new subgoals for the LIFO discipline*)
cc3e8453d7f0 More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents: 4354
diff changeset
   482
local
cc3e8453d7f0 More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents: 4354
diff changeset
   483
  (*Count new hyps so that they can be rotated*)
cc3e8453d7f0 More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents: 4354
diff changeset
   484
  fun nNewHyps []                         = 0
cc3e8453d7f0 More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents: 4354
diff changeset
   485
    | nNewHyps (Const "*Goal*" $ _ :: Ps) = nNewHyps Ps
cc3e8453d7f0 More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents: 4354
diff changeset
   486
    | nNewHyps (P::Ps)                    = 1 + nNewHyps Ps;
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   487
5463
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
   488
  fun rot_tac [] i st      = Seq.single st
4391
cc3e8453d7f0 More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents: 4354
diff changeset
   489
    | rot_tac (0::ks) i st = rot_tac ks (i+1) st
cc3e8453d7f0 More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents: 4354
diff changeset
   490
    | rot_tac (k::ks) i st = rot_tac ks (i+1) (rotate_rule (~k) i st);
cc3e8453d7f0 More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents: 4354
diff changeset
   491
in
cc3e8453d7f0 More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents: 4354
diff changeset
   492
fun rot_subgoals_tac (rot, rl) =
cc3e8453d7f0 More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents: 4354
diff changeset
   493
     rot_tac (if rot then map nNewHyps rl else []) 
cc3e8453d7f0 More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents: 4354
diff changeset
   494
end;
cc3e8453d7f0 More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents: 4354
diff changeset
   495
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   496
2999
fad7cc426242 Penalty for branching instantiations reduced from log3 to log4.
paulson
parents: 2952
diff changeset
   497
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
   498
5343
871b77df79a0 new version, more resistant to PROOF FAILED. Now it distinguishes between
paulson
parents: 4653
diff changeset
   499
(*Resolution/matching tactics: if upd then the proof state may be updated.
871b77df79a0 new version, more resistant to PROOF FAILED. Now it distinguishes between
paulson
parents: 4653
diff changeset
   500
  Matching makes the tactics more deterministic in the presence of Vars.*)
871b77df79a0 new version, more resistant to PROOF FAILED. Now it distinguishes between
paulson
parents: 4653
diff changeset
   501
fun emtac upd rl = TRACE rl (if upd then etac rl else ematch_tac [rl]);
871b77df79a0 new version, more resistant to PROOF FAILED. Now it distinguishes between
paulson
parents: 4653
diff changeset
   502
fun rmtac upd rl = TRACE rl (if upd then rtac rl else match_tac [rl]);
871b77df79a0 new version, more resistant to PROOF FAILED. Now it distinguishes between
paulson
parents: 4653
diff changeset
   503
871b77df79a0 new version, more resistant to PROOF FAILED. Now it distinguishes between
paulson
parents: 4653
diff changeset
   504
(*Tableau rule from elimination rule.  
871b77df79a0 new version, more resistant to PROOF FAILED. Now it distinguishes between
paulson
parents: 4653
diff changeset
   505
  Flag "upd" says that the inference updated the branch.
871b77df79a0 new version, more resistant to PROOF FAILED. Now it distinguishes between
paulson
parents: 4653
diff changeset
   506
  Flag "dup" requests duplication of the affected formula.*)
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   507
fun fromRule vars rl = 
4065
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   508
  let val trl = rl |> rep_thm |> #prop |> fromTerm |> convertRule vars
5343
871b77df79a0 new version, more resistant to PROOF FAILED. Now it distinguishes between
paulson
parents: 4653
diff changeset
   509
      fun tac (upd, dup,rot) i = 
871b77df79a0 new version, more resistant to PROOF FAILED. Now it distinguishes between
paulson
parents: 4653
diff changeset
   510
	emtac upd (if dup then rev_dup_elim rl else rl) i
4391
cc3e8453d7f0 More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents: 4354
diff changeset
   511
	THEN
cc3e8453d7f0 More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents: 4354
diff changeset
   512
	rot_subgoals_tac (rot, #2 trl) i
3244
71b760618f30 Basis library version of type "option" now resides in its own structure Option
paulson
parents: 3101
diff changeset
   513
  in Option.SOME (trl, tac) end
9170
0bfe5354d5e7 warns of weak elim rules and ignores them
paulson
parents: 7607
diff changeset
   514
  handle ElimBadPrem => (*reject: prems don't preserve conclusion*)
0bfe5354d5e7 warns of weak elim rules and ignores them
paulson
parents: 7607
diff changeset
   515
	    (warning("Ignoring weak elimination rule\n" ^ string_of_thm rl);
0bfe5354d5e7 warns of weak elim rules and ignores them
paulson
parents: 7607
diff changeset
   516
	     Option.NONE)
0bfe5354d5e7 warns of weak elim rules and ignores them
paulson
parents: 7607
diff changeset
   517
       | ElimBadConcl => (*ignore: conclusion is not just a variable*)
0bfe5354d5e7 warns of weak elim rules and ignores them
paulson
parents: 7607
diff changeset
   518
	   (if !trace then (warning("Ignoring ill-formed elimination rule:\n" ^
0bfe5354d5e7 warns of weak elim rules and ignores them
paulson
parents: 7607
diff changeset
   519
       	               "conclusion should be a variable\n" ^ string_of_thm rl))
0bfe5354d5e7 warns of weak elim rules and ignores them
paulson
parents: 7607
diff changeset
   520
	    else ();
0bfe5354d5e7 warns of weak elim rules and ignores them
paulson
parents: 7607
diff changeset
   521
	    Option.NONE);
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   522
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   523
3101
e8a92f497295 Again "norm" DOES NOT normalize bodies of abstractions
paulson
parents: 3092
diff changeset
   524
(*** Conversion of Introduction Rules ***)
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   525
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   526
fun convertIntrPrem t = mkGoal (strip_imp_concl t) :: strip_imp_prems t;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   527
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   528
fun convertIntrRule vars t =
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   529
  let val Ps = strip_imp_prems t
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   530
      val P  = strip_imp_concl t
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   531
  in  (mkGoal P, map (convertIntrPrem o skoPrem vars) Ps) 
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   532
  end;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   533
5343
871b77df79a0 new version, more resistant to PROOF FAILED. Now it distinguishes between
paulson
parents: 4653
diff changeset
   534
(*Tableau rule from introduction rule.  
871b77df79a0 new version, more resistant to PROOF FAILED. Now it distinguishes between
paulson
parents: 4653
diff changeset
   535
  Flag "upd" says that the inference updated the branch.
871b77df79a0 new version, more resistant to PROOF FAILED. Now it distinguishes between
paulson
parents: 4653
diff changeset
   536
  Flag "dup" requests duplication of the affected formula.
871b77df79a0 new version, more resistant to PROOF FAILED. Now it distinguishes between
paulson
parents: 4653
diff changeset
   537
  Since haz rules are now delayed, "dup" is always FALSE for
871b77df79a0 new version, more resistant to PROOF FAILED. Now it distinguishes between
paulson
parents: 4653
diff changeset
   538
  introduction rules.*)
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   539
fun fromIntrRule vars rl = 
4065
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   540
  let val trl = rl |> rep_thm |> #prop |> fromTerm |> convertIntrRule vars
5343
871b77df79a0 new version, more resistant to PROOF FAILED. Now it distinguishes between
paulson
parents: 4653
diff changeset
   541
      fun tac (upd,dup,rot) i = 
871b77df79a0 new version, more resistant to PROOF FAILED. Now it distinguishes between
paulson
parents: 4653
diff changeset
   542
	 rmtac upd (if dup then Data.dup_intr rl else rl) i
4391
cc3e8453d7f0 More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents: 4354
diff changeset
   543
	 THEN
cc3e8453d7f0 More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents: 4354
diff changeset
   544
	 rot_subgoals_tac (rot, #2 trl) i
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   545
  in (trl, tac) end;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   546
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   547
3030
04e3359921a8 Addition of printed tracing. Also some tidying
paulson
parents: 3021
diff changeset
   548
val dummyVar = Term.Var (("etc",0), dummyT);
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   549
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   550
(*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
   551
  Ignore abstractions; identify all Vars; STOP at given depth*)
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
   552
fun toTerm 0 _             = dummyVar
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
   553
  | toTerm d (Const a)     = Term.Const (a,dummyT)
4065
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   554
  | toTerm d (TConst(a,_)) = Term.Const (a,dummyT)  (*no need to convert type*)
2924
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
   555
  | toTerm d (Skolem(a,_)) = Term.Const (a,dummyT)
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
   556
  | toTerm d (Free a)      = Term.Free  (a,dummyT)
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
   557
  | toTerm d (Bound i)     = Term.Bound i
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
   558
  | toTerm d (Var _)       = dummyVar
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
   559
  | toTerm d (Abs(a,_))    = dummyVar
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
   560
  | 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
   561
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   562
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   563
fun netMkRules P vars (nps: netpair list) =
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   564
  case P of
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   565
      (Const "*Goal*" $ G) =>
2924
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
   566
	let val pG = mk_tprop (toTerm 2 G)
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   567
	    val intrs = List.concat 
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   568
		             (map (fn (inet,_) => Net.unify_term inet pG) 
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   569
			      nps)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   570
	in  map (fromIntrRule vars o #2) (orderlist intrs)  end
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   571
    | _ =>
2924
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
   572
	let val pP = mk_tprop (toTerm 3 P)
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   573
	    val elims = List.concat 
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   574
		             (map (fn (_,enet) => Net.unify_term enet pP) 
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   575
			      nps)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   576
	in  List.mapPartial (fromRule vars o #2) (orderlist elims)  end;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   577
3092
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   578
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   579
(*Pending formulae carry md (may duplicate) flags*)
5463
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
   580
type branch = 
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
   581
    {pairs: ((term*bool) list *	(*safe formulae on this level*)
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
   582
               (term*bool) list) list,  (*haz formulae  on this level*)
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
   583
     lits:   term list,                 (*literals: irreducible formulae*)
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
   584
     vars:   term option ref list,      (*variables occurring in branch*)
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
   585
     lim:    int};                      (*resource limit*)
3092
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   586
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   587
val fullTrace = ref[] : branch list list ref;
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   588
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   589
(*Normalize a branch--for tracing*)
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   590
fun norm2 (G,md) = (norm G, md);
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   591
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   592
fun normLev (Gs,Hs) = (map norm2 Gs, map norm2 Hs);
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   593
5463
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
   594
fun normBr {pairs, lits, vars, lim} =
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
   595
     {pairs = map normLev pairs, 
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
   596
      lits  = map norm lits, 
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
   597
      vars  = vars, 
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
   598
      lim   = lim};
3092
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
4065
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   601
val dummyTVar = Term.TVar(("a",0), []);
3092
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   602
val dummyVar2 = Term.Var(("var",0), dummyT);
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   603
4065
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   604
(*convert Blast_tac's type representation to real types for tracing*)
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   605
fun showType (Free a)  = Term.TFree (a,[])
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   606
  | showType (Var _)   = dummyTVar
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   607
  | showType t         =
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   608
      (case strip_comb t of
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   609
	   (Const a, us) => Term.Type(a, map showType us)
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   610
	 | _ => dummyT);
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   611
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   612
(*Display top-level overloading if any*)
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   613
fun topType (TConst(a,t)) = Some (showType t)
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   614
  | topType (Abs(a,t))    = topType t
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   615
  | topType (f $ u)       = (case topType f of
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   616
				 None => topType u
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   617
			       | some => some)
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   618
  | topType _             = None;
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   619
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   620
3092
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   621
(*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
   622
fun showTerm d (Const a)     = Term.Const (a,dummyT)
4065
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   623
  | showTerm d (TConst(a,_)) = Term.Const (a,dummyT)
3092
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   624
  | showTerm d (Skolem(a,_)) = Term.Const (a,dummyT)
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   625
  | showTerm d (Free a)      = Term.Free  (a,dummyT)
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   626
  | showTerm d (Bound i)     = Term.Bound i
3101
e8a92f497295 Again "norm" DOES NOT normalize bodies of abstractions
paulson
parents: 3092
diff changeset
   627
  | showTerm d (Var(ref(Some u))) = showTerm d u
e8a92f497295 Again "norm" DOES NOT normalize bodies of abstractions
paulson
parents: 3092
diff changeset
   628
  | showTerm d (Var(ref None))    = dummyVar2
3092
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   629
  | showTerm d (Abs(a,t))    = if d=0 then dummyVar
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   630
			       else Term.Abs(a, dummyT, showTerm (d-1) t)
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   631
  | showTerm d (f $ u)       = if d=0 then dummyVar
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   632
			       else Term.$ (showTerm d f, showTerm (d-1) u);
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   633
4065
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   634
fun string_of sign d t = Sign.string_of_term sign (showTerm d t);
3092
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   635
4065
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   636
fun traceTerm sign t = 
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   637
  let val t' = norm t
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   638
      val stm = string_of sign 8 t'
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   639
  in  
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   640
      case topType t' of
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   641
	  None   => stm   (*no type to attach*)
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   642
	| Some T => stm ^ "\t:: " ^ Sign.string_of_typ sign T
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   643
  end;
3092
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   644
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   645
5961
6cf4e46ce95a replaced prs by std_output / writeln;
wenzelm
parents: 5926
diff changeset
   646
val prs = std_output;
6cf4e46ce95a replaced prs by std_output / writeln;
wenzelm
parents: 5926
diff changeset
   647
3092
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   648
(*Print tracing information at each iteration of prover*)
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   649
fun tracing sign brs = 
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   650
  let fun printPairs (((G,_)::_,_)::_)  = prs(traceTerm sign G)
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   651
	| printPairs (([],(H,_)::_)::_) = prs(traceTerm sign H ^ "\t (Unsafe)")
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   652
	| printPairs _                 = ()
5463
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
   653
      fun printBrs (brs0 as {pairs, lits, lim, ...} :: brs) =
3092
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   654
	    (fullTrace := brs0 :: !fullTrace;
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   655
	     seq (fn _ => prs "+") brs;
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   656
	     prs (" [" ^ Int.toString lim ^ "] ");
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   657
	     printPairs pairs;
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   658
	     writeln"")
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   659
  in if !trace then printBrs (map normBr brs) else ()
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   660
  end;
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   661
5343
871b77df79a0 new version, more resistant to PROOF FAILED. Now it distinguishes between
paulson
parents: 4653
diff changeset
   662
fun traceMsg s = if !trace then writeln s else ();
4065
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   663
3092
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   664
(*Tracing: variables updated in the last branch operation?*)
4065
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   665
fun traceVars sign ntrl =
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   666
  if !trace then 
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   667
      (case !ntrail-ntrl of
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   668
	    0 => ()
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   669
	  | 1 => prs"\t1 variable UPDATED:"
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   670
	  | n => prs("\t" ^ Int.toString n ^ " variables UPDATED:");
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   671
       (*display the instantiations themselves, though no variable names*)
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   672
       seq (fn v => prs("   " ^ string_of sign 4 (the (!v))))
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   673
           (List.take(!trail, !ntrail-ntrl));
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   674
       writeln"")
3092
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   675
    else ();
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   676
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   677
(*Tracing: how many new branches are created?*)
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   678
fun traceNew prems =
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   679
    if !trace then 
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   680
        case length prems of
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   681
	    0 => prs"branch closed by rule"
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   682
	  | 1 => prs"branch extended (1 new subgoal)"
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   683
	  | n => prs("branch split: "^ Int.toString n ^ " new subgoals")
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   684
    else ();
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   685
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   686
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   687
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   688
(*** Code for handling equality: naive substitution, like hyp_subst_tac ***)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   689
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   690
(*Replace the ATOMIC term "old" by "new" in t*)  
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   691
fun subst_atomic (old,new) t =
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   692
    let fun subst (Var(ref(Some u))) = subst u
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   693
	  | subst (Abs(a,body))      = Abs(a, subst body)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   694
	  | subst (f$t)              = subst f $ subst t
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   695
	  | subst t                  = if t aconv old then new else t
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   696
    in  subst t  end;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   697
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   698
(*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
   699
fun eta_contract_atom (t0 as Abs(a, body)) = 
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   700
      (case  eta_contract2 body  of
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   701
        f $ Bound 0 => if (0 mem_int loose_bnos f) then t0
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   702
		       else eta_contract_atom (incr_boundvars ~1 f)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   703
      | _ => t0)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   704
  | eta_contract_atom t = t
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   705
and eta_contract2 (f$t) = f $ eta_contract_atom t
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   706
  | eta_contract2 t     = eta_contract_atom t;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   707
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
(*When can we safely delete the equality?
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   710
    Not if it equates two constants; consider 0=1.
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   711
    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
   712
    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
   713
  Prefer to eliminate Bound variables if possible.
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   714
  Result:  true = use as is,  false = reorient first *)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   715
4354
7f4da01bdf0e Fixed the treatment of substitution for equations, restricting occurrences of
paulson
parents: 4323
diff changeset
   716
(*Can t occur in u?  For substitution.  
7f4da01bdf0e Fixed the treatment of substitution for equations, restricting occurrences of
paulson
parents: 4323
diff changeset
   717
  Does NOT examine the args of Skolem terms: substitution does not affect them.
4196
9953c0995b79 Now applies "map negOfGoal" to lits when expanding haz rules.
paulson
parents: 4149
diff changeset
   718
  REFLEXIVE because hyp_subst_tac fails on x=x.*)
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   719
fun substOccur t = 
4354
7f4da01bdf0e Fixed the treatment of substitution for equations, restricting occurrences of
paulson
parents: 4323
diff changeset
   720
  let (*NO vars are permitted in u except the arguments of t, if it is 
7f4da01bdf0e Fixed the treatment of substitution for equations, restricting occurrences of
paulson
parents: 4323
diff changeset
   721
        a Skolem term.  This ensures that no equations are deleted that could
7f4da01bdf0e Fixed the treatment of substitution for equations, restricting occurrences of
paulson
parents: 4323
diff changeset
   722
        be instantiated to a cycle.  For example, x=?a is rejected because ?a
7f4da01bdf0e Fixed the treatment of substitution for equations, restricting occurrences of
paulson
parents: 4323
diff changeset
   723
	could be instantiated to Suc(x).*)
7f4da01bdf0e Fixed the treatment of substitution for equations, restricting occurrences of
paulson
parents: 4323
diff changeset
   724
      val vars = case t of
7f4da01bdf0e Fixed the treatment of substitution for equations, restricting occurrences of
paulson
parents: 4323
diff changeset
   725
                     Skolem(_,vars) => vars
7f4da01bdf0e Fixed the treatment of substitution for equations, restricting occurrences of
paulson
parents: 4323
diff changeset
   726
		   | _ => []
7f4da01bdf0e Fixed the treatment of substitution for equations, restricting occurrences of
paulson
parents: 4323
diff changeset
   727
      fun occEq u = (t aconv u) orelse occ u
7f4da01bdf0e Fixed the treatment of substitution for equations, restricting occurrences of
paulson
parents: 4323
diff changeset
   728
      and occ (Var(ref(Some u))) = occEq u
7f4da01bdf0e Fixed the treatment of substitution for equations, restricting occurrences of
paulson
parents: 4323
diff changeset
   729
        | occ (Var v)            = not (mem_var (v, vars))
7f4da01bdf0e Fixed the treatment of substitution for equations, restricting occurrences of
paulson
parents: 4323
diff changeset
   730
	| occ (Abs(_,u))         = occEq u
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   731
        | occ (f$u)              = occEq u  orelse  occEq f
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   732
        | occ (_)                = false;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   733
  in  occEq  end;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   734
3092
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   735
exception DEST_EQ;
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   736
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   737
(*Take apart an equality (plain or overloaded).  NO constant Trueprop*)
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   738
fun dest_eq (Const  "op ="     $ t $ u) = 
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   739
		(eta_contract_atom t, eta_contract_atom u)
4065
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   740
  | dest_eq (TConst("op =",_)  $ t $ u) = 
3092
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   741
		(eta_contract_atom t, eta_contract_atom u)
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   742
  | dest_eq _                           = raise DEST_EQ;
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   743
4196
9953c0995b79 Now applies "map negOfGoal" to lits when expanding haz rules.
paulson
parents: 4149
diff changeset
   744
(*Reject the equality if u occurs in (or equals!) t*)
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   745
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
   746
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   747
(*IF the goal is an equality with a substitutable variable 
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   748
  THEN orient that equality ELSE raise exception DEST_EQ*)
3092
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   749
fun orientGoal (t,u) = case (t,u) of
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   750
       (Skolem _, _) => check(t,u,(t,u))	(*eliminates t*)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   751
     | (_, Skolem _) => check(u,t,(u,t))	(*eliminates u*)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   752
     | (Free _, _)   => check(t,u,(t,u))	(*eliminates t*)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   753
     | (_, Free _)   => check(u,t,(u,t))	(*eliminates u*)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   754
     | _             => raise DEST_EQ;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   755
2894
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   756
(*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
   757
  Moves affected literals back into the branch, but it is not clear where
4391
cc3e8453d7f0 More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents: 4354
diff changeset
   758
  they should go: this could make proofs fail.*)
5463
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
   759
fun equalSubst sign (G, {pairs, lits, vars, lim}) = 
3092
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   760
  let val (t,u) = orientGoal(dest_eq G)
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   761
      val subst = subst_atomic (t,u)
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   762
      fun subst2(G,md) = (subst G, md)
4466
305390f23734 Better equality handling in Blast_tac, usingd a new variant of hyp_subst_tac
paulson
parents: 4391
diff changeset
   763
      (*substitute throughout list; extract affected formulae*)
305390f23734 Better equality handling in Blast_tac, usingd a new variant of hyp_subst_tac
paulson
parents: 4391
diff changeset
   764
      fun subForm ((G,md), (changed, pairs)) =
305390f23734 Better equality handling in Blast_tac, usingd a new variant of hyp_subst_tac
paulson
parents: 4391
diff changeset
   765
	    let val nG = subst G
305390f23734 Better equality handling in Blast_tac, usingd a new variant of hyp_subst_tac
paulson
parents: 4391
diff changeset
   766
	    in  if nG aconv G then (changed, (G,md)::pairs)
305390f23734 Better equality handling in Blast_tac, usingd a new variant of hyp_subst_tac
paulson
parents: 4391
diff changeset
   767
		              else ((nG,md)::changed, pairs)
2924
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
   768
            end
4466
305390f23734 Better equality handling in Blast_tac, usingd a new variant of hyp_subst_tac
paulson
parents: 4391
diff changeset
   769
      (*substitute throughout "stack frame"; extract affected formulae*)
305390f23734 Better equality handling in Blast_tac, usingd a new variant of hyp_subst_tac
paulson
parents: 4391
diff changeset
   770
      fun subFrame ((Gs,Hs), (changed, frames)) =
305390f23734 Better equality handling in Blast_tac, usingd a new variant of hyp_subst_tac
paulson
parents: 4391
diff changeset
   771
	    let val (changed', Gs') = foldr subForm (Gs, (changed, []))
305390f23734 Better equality handling in Blast_tac, usingd a new variant of hyp_subst_tac
paulson
parents: 4391
diff changeset
   772
                val (changed'', Hs') = foldr subForm (Hs, (changed', []))
305390f23734 Better equality handling in Blast_tac, usingd a new variant of hyp_subst_tac
paulson
parents: 4391
diff changeset
   773
            in  (changed'', (Gs',Hs')::frames)  end
305390f23734 Better equality handling in Blast_tac, usingd a new variant of hyp_subst_tac
paulson
parents: 4391
diff changeset
   774
      (*substitute throughout literals; extract affected ones*)
305390f23734 Better equality handling in Blast_tac, usingd a new variant of hyp_subst_tac
paulson
parents: 4391
diff changeset
   775
      fun subLit (lit, (changed, nlits)) =
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   776
	    let val nlit = subst lit
4466
305390f23734 Better equality handling in Blast_tac, usingd a new variant of hyp_subst_tac
paulson
parents: 4391
diff changeset
   777
	    in  if nlit aconv lit then (changed, nlit::nlits)
305390f23734 Better equality handling in Blast_tac, usingd a new variant of hyp_subst_tac
paulson
parents: 4391
diff changeset
   778
		                  else ((nlit,true)::changed, nlits)
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   779
            end
4466
305390f23734 Better equality handling in Blast_tac, usingd a new variant of hyp_subst_tac
paulson
parents: 4391
diff changeset
   780
      val (changed, lits') = foldr subLit (lits, ([], []))
305390f23734 Better equality handling in Blast_tac, usingd a new variant of hyp_subst_tac
paulson
parents: 4391
diff changeset
   781
      val (changed', pairs') = foldr subFrame (pairs, (changed, []))
3092
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   782
  in  if !trace then writeln ("Substituting " ^ traceTerm sign u ^
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   783
			      " for " ^ traceTerm sign t ^ " in branch" )
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
   784
      else ();
5463
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
   785
      {pairs = (changed',[])::pairs',	(*affected formulas, and others*)
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
   786
       lits  = lits',			(*unaffected literals*)
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
   787
       vars  = vars, 
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
   788
       lim   = lim}
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   789
  end;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   790
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   791
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   792
exception NEWBRANCHES and CLOSEF;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   793
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   794
exception PROVE;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   795
4391
cc3e8453d7f0 More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents: 4354
diff changeset
   796
(*Trying eq_contr_tac first INCREASES the effort, slowing reconstruction*)
cc3e8453d7f0 More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents: 4354
diff changeset
   797
val contr_tac = ematch_tac [Data.notE] THEN' 
cc3e8453d7f0 More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents: 4354
diff changeset
   798
                (eq_assume_tac ORELSE' assume_tac);
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   799
4391
cc3e8453d7f0 More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents: 4354
diff changeset
   800
val eContr_tac  = TRACE Data.notE contr_tac;
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   801
val eAssume_tac = TRACE asm_rl   (eq_assume_tac ORELSE' assume_tac);
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   802
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   803
(*Try to unify complementary literals and return the corresponding tactic. *) 
3083
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   804
fun tryClose (Const"*Goal*" $ G,  L) = 
4065
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   805
	if unify([],G,L) then Some eAssume_tac else None
3083
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   806
  | tryClose (G,  Const"*Goal*" $ L) = 
4065
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   807
	if unify([],G,L) then Some eAssume_tac else None
3083
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   808
  | tryClose (Const"Not" $ G,  L)    = 
4065
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   809
	if unify([],G,L) then Some eContr_tac else None
3083
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   810
  | tryClose (G,  Const"Not" $ L)    = 
4065
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   811
	if unify([],G,L) then Some eContr_tac else None
3083
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   812
  | tryClose _                       = None;
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   813
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   814
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   815
(*Were there Skolem terms in the premise?  Must NOT chase Vars*)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   816
fun hasSkolem (Skolem _)     = true
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   817
  | hasSkolem (Abs (_,body)) = hasSkolem body 
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   818
  | hasSkolem (f$t)          =  hasSkolem f orelse hasSkolem t
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   819
  | hasSkolem _              = false;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   820
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   821
(*Attach the right "may duplicate" flag to new formulae: if they contain
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   822
  Skolem terms then allow duplication.*)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   823
fun joinMd md [] = []
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   824
  | joinMd md (G::Gs) = (G, hasSkolem G orelse md) :: joinMd md Gs;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   825
2894
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   826
(*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
   827
  Ex(P) is duplicated as the assumption ~Ex(P). *)
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   828
fun negOfGoal (Const"*Goal*" $ G) = negate G
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   829
  | negOfGoal G                   = G;
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   830
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   831
fun negOfGoal2 (G,md) = (negOfGoal G, md);
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   832
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   833
(*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
   834
  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
   835
  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
   836
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
   837
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   838
(*Tactic.  Convert *Goal* to negated assumption in FIRST position*)
4391
cc3e8453d7f0 More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents: 4354
diff changeset
   839
fun negOfGoal_tac i = TRACE Data.ccontr (rtac Data.ccontr) i THEN
cc3e8453d7f0 More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents: 4354
diff changeset
   840
                      rotate_tac ~1 i;
2894
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   841
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   842
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   843
(** Backtracking and Pruning **)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   844
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   845
(*clashVar vars (n,trail) determines whether any of the last n elements
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   846
  of "trail" occur in "vars" OR in their instantiations*)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   847
fun clashVar [] = (fn _ => false)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   848
  | clashVar vars =
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   849
      let fun clash (0, _)     = false
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   850
	    | clash (_, [])    = false
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   851
	    | 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
   852
      in  clash  end;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   853
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   855
(*nbrs = # of branches just prior to closing this one.  Delete choice points
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   856
  for goals proved by the latest inference, provided NO variables in the
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   857
  next branch have been updated.*)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   858
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
   859
					     backtracking over bad proofs*)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   860
  | prune (nbrs, nxtVars, choices) =
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   861
      let fun traceIt last =
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   862
		let val ll = length last
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   863
		    and lc = length choices
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   864
		in if !trace andalso ll<lc then
3083
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   865
		    (writeln("Pruning " ^ Int.toString(lc-ll) ^ " levels"); 
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   866
		     last)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   867
		   else last
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   868
		end
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   869
	  fun pruneAux (last, _, _, []) = last
3083
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   870
	    | pruneAux (last, ntrl, trl, (ntrl',nbrs',exn) :: choices) =
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   871
		if nbrs' < nbrs 
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   872
		then last  (*don't backtrack beyond first solution of goal*)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   873
		else if nbrs' > nbrs then pruneAux (last, ntrl, trl, choices)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   874
		else (* nbrs'=nbrs *)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   875
		     if clashVar nxtVars (ntrl-ntrl', trl) then last
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   876
		     else (*no clashes: can go back at least this far!*)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   877
			  pruneAux(choices, ntrl', List.drop(trl, ntrl-ntrl'), 
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   878
				   choices)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   879
  in  traceIt (pruneAux (choices, !ntrail, !trail, choices))  end;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   880
5463
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
   881
fun nextVars ({pairs, lits, vars, lim} :: _) = map Var vars
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
   882
  | nextVars []                              = [];
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   883
3083
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   884
fun backtrack (choices as (ntrl, nbrs, exn)::_) = 
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   885
      (if !trace then (writeln ("Backtracking; now there are " ^ 
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   886
				Int.toString nbrs ^ " branches"))
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   887
                 else (); 
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   888
       raise exn)
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   889
  | backtrack _ = raise PROVE;
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   890
2894
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   891
(*Add the literal G, handling *Goal* and detecting duplicates.*)
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   892
fun addLit (Const "*Goal*" $ G, lits) = 
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   893
      (*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
   894
      let fun bad (Const"*Goal*" $ _) = true
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   895
	    | bad (Const"Not" $ G')   = G aconv G'
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   896
	    | bad _                   = false;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   897
	  fun change [] = []
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   898
	    | change (Const"*Goal*" $ G' :: lits) = 
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   899
		  if G aconv G' then change lits
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   900
		  else Const"Not" $ G' :: change lits
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   901
	    | change (Const"Not" $ G' :: lits)    = 
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   902
		  if G aconv G' then change lits
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   903
		  else Const"Not" $ G' :: change lits
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   904
	    | change (lit::lits) = lit :: change lits
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   905
      in
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   906
	Const "*Goal*" $ G :: (if exists bad lits then change lits else lits)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   907
      end
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   908
  | addLit (G,lits) = ins_term(G, lits)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   909
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   910
2952
ea834e8fac1b Changed penalty from log2 to log3
paulson
parents: 2924
diff changeset
   911
(*For calculating the "penalty" to assess on a branching factor of n
ea834e8fac1b Changed penalty from log2 to log3
paulson
parents: 2924
diff changeset
   912
  log2 seems a little too severe*)
3083
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   913
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
   914
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
   915
3021
39806db47be9 Loop detection: before expanding a haz formula, see whether it is a duplicate
paulson
parents: 2999
diff changeset
   916
(*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
   917
  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
   918
fun match (Var _) u   = true
4065
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   919
  | match (Const"*Goal*") (Const"Not")    = true
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   920
  | match (Const"Not")    (Const"*Goal*") = true
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   921
  | match (Const a)       (Const b)       = (a=b)
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   922
  | match (TConst (a,ta)) (TConst (b,tb)) = a=b andalso match ta tb
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   923
  | match (Free a)        (Free b)        = (a=b)
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   924
  | match (Bound i)       (Bound j)       = (i=j)
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   925
  | match (Abs(_,t))      (Abs(_,u))      = match t u
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   926
  | match (f$t)           (g$u)           = match f g andalso match t u
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   927
  | match t               u   = false;
3021
39806db47be9 Loop detection: before expanding a haz formula, see whether it is a duplicate
paulson
parents: 2999
diff changeset
   928
39806db47be9 Loop detection: before expanding a haz formula, see whether it is a duplicate
paulson
parents: 2999
diff changeset
   929
4300
451ae21dca28 Statistics
paulson
parents: 4271
diff changeset
   930
(*Branches closed: number of branches closed during the search
451ae21dca28 Statistics
paulson
parents: 4271
diff changeset
   931
  Branches tried:  number of branches created by splitting (counting from 1)*)
451ae21dca28 Statistics
paulson
parents: 4271
diff changeset
   932
val nclosed = ref 0
451ae21dca28 Statistics
paulson
parents: 4271
diff changeset
   933
and ntried  = ref 1;
451ae21dca28 Statistics
paulson
parents: 4271
diff changeset
   934
4391
cc3e8453d7f0 More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents: 4354
diff changeset
   935
fun printStats (b, start, tacs) =
4323
561242f8606b Printing of statistics including time for search & reconstruction
paulson
parents: 4300
diff changeset
   936
  if b then
561242f8606b Printing of statistics including time for search & reconstruction
paulson
parents: 4300
diff changeset
   937
    writeln (endTiming start ^ " for search.  Closed: " 
561242f8606b Printing of statistics including time for search & reconstruction
paulson
parents: 4300
diff changeset
   938
	     ^ Int.toString (!nclosed) ^
4391
cc3e8453d7f0 More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents: 4354
diff changeset
   939
             " tried: " ^ Int.toString (!ntried) ^
cc3e8453d7f0 More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents: 4354
diff changeset
   940
             " tactics: " ^ Int.toString (length tacs))
4323
561242f8606b Printing of statistics including time for search & reconstruction
paulson
parents: 4300
diff changeset
   941
  else ();
561242f8606b Printing of statistics including time for search & reconstruction
paulson
parents: 4300
diff changeset
   942
561242f8606b Printing of statistics including time for search & reconstruction
paulson
parents: 4300
diff changeset
   943
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   944
(*Tableau prover based on leanTaP.  Argument is a list of branches.  Each 
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   945
  branch contains a list of unexpanded formulae, a list of literals, and a 
4391
cc3e8453d7f0 More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents: 4354
diff changeset
   946
  bound on unsafe expansions.
cc3e8453d7f0 More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents: 4354
diff changeset
   947
 "start" is CPU time at start, for printing search time
cc3e8453d7f0 More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents: 4354
diff changeset
   948
*)
cc3e8453d7f0 More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents: 4354
diff changeset
   949
fun prove (sign, start, cs, brs, cont) =
4653
d60f76680bf4 renamed rep_claset to rep_cs
oheimb
parents: 4651
diff changeset
   950
 let val {safe0_netpair, safep_netpair, haz_netpair, ...} = Data.rep_cs cs
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   951
     val safeList = [safe0_netpair, safep_netpair]
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   952
     and hazList  = [haz_netpair]
4065
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   953
     fun prv (tacs, trs, choices, []) = 
4391
cc3e8453d7f0 More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents: 4354
diff changeset
   954
	        (printStats (!trace orelse !stats, start, tacs); 
4323
561242f8606b Printing of statistics including time for search & reconstruction
paulson
parents: 4300
diff changeset
   955
		 cont (tacs, trs, choices))   (*all branches closed!*)
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   956
       | prv (tacs, trs, choices, 
5463
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
   957
	      brs0 as {pairs = ((G,md)::br, haz)::pairs, 
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
   958
		       lits, vars, lim} :: brs) =
3917
6ea5f9101c3e A lot of new comments
paulson
parents: 3533
diff changeset
   959
   	     (*apply a safe rule only (possibly allowing instantiation);
6ea5f9101c3e A lot of new comments
paulson
parents: 3533
diff changeset
   960
               defer any haz formulae*)
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   961
	  let exception PRV (*backtrack to precisely this recursion!*)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   962
	      val ntrl = !ntrail 
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   963
	      val nbrs = length brs0
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   964
              val nxtVars = nextVars brs
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   965
	      val G = norm G
2924
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
   966
	      val rules = netMkRules G vars safeList
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   967
	      (*Make a new branch, decrementing "lim" if instantiations occur*)
2894
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   968
	      fun newBr (vars',lim') prems =
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   969
		  map (fn prem => 
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
   970
		       if (exists isGoal prem) 
5463
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
   971
		       then {pairs = ((joinMd md prem, []) :: 
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
   972
				      negOfGoals ((br, haz)::pairs)),
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
   973
			     lits  = map negOfGoal lits, 
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
   974
			     vars  = vars', 
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
   975
			     lim   = lim'}
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
   976
		       else {pairs = ((joinMd md prem, []) :: 
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
   977
				      (br, haz) :: pairs),
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
   978
			     lits = lits, 
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
   979
			     vars = vars', 
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
   980
			     lim  = lim'})
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   981
		  prems @
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   982
		  brs		  
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   983
	      (*Seek a matching rule.  If unifiable then add new premises
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   984
                to branch.*)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   985
	      fun deeper [] = raise NEWBRANCHES
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
   986
		| deeper (((P,prems),tac)::grls) =
4065
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   987
		    if unify(add_term_vars(P,[]), P, G) 
3083
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   988
		    then  (*P comes from the rule; G comes from the branch.*)
5343
871b77df79a0 new version, more resistant to PROOF FAILED. Now it distinguishes between
paulson
parents: 4653
diff changeset
   989
		     let val updated = ntrl < !ntrail (*branch updated*)
871b77df79a0 new version, more resistant to PROOF FAILED. Now it distinguishes between
paulson
parents: 4653
diff changeset
   990
			 val lim' = if updated
3083
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   991
				    then lim - (1+log(length rules))
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   992
				    else lim   (*discourage branching updates*)
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   993
			 val vars  = vars_in_vars vars
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   994
			 val vars' = foldr add_terms_vars (prems, vars)
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   995
			 val choices' = (ntrl, nbrs, PRV) :: choices
5463
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
   996
			 val tacs' = (tac(updated,false,true)) 
5343
871b77df79a0 new version, more resistant to PROOF FAILED. Now it distinguishes between
paulson
parents: 4653
diff changeset
   997
                                     :: tacs  (*no duplication; rotate*)
3083
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
   998
		     in
4065
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
   999
			 traceNew prems;  traceVars sign ntrl;
3083
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1000
			 (if null prems then (*closed the branch: prune!*)
4300
451ae21dca28 Statistics
paulson
parents: 4271
diff changeset
  1001
			    (nclosed := !nclosed + 1;
451ae21dca28 Statistics
paulson
parents: 4271
diff changeset
  1002
			     prv(tacs',  brs0::trs, 
451ae21dca28 Statistics
paulson
parents: 4271
diff changeset
  1003
				 prune (nbrs, nxtVars, choices'),
451ae21dca28 Statistics
paulson
parents: 4271
diff changeset
  1004
				 brs))
451ae21dca28 Statistics
paulson
parents: 4271
diff changeset
  1005
			  else (*prems non-null*)
3083
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1006
			  if lim'<0 (*faster to kill ALL the alternatives*)
5343
871b77df79a0 new version, more resistant to PROOF FAILED. Now it distinguishes between
paulson
parents: 4653
diff changeset
  1007
			  then (traceMsg"Excessive branching: KILLED";
4065
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
  1008
			        clearTo ntrl;  raise NEWBRANCHES)
3083
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1009
			  else
4300
451ae21dca28 Statistics
paulson
parents: 4271
diff changeset
  1010
			    (ntried := !ntried + length prems - 1;
451ae21dca28 Statistics
paulson
parents: 4271
diff changeset
  1011
			     prv(tacs',  brs0::trs, choices',
451ae21dca28 Statistics
paulson
parents: 4271
diff changeset
  1012
				 newBr (vars',lim') prems)))
3083
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1013
                         handle PRV => 
5343
871b77df79a0 new version, more resistant to PROOF FAILED. Now it distinguishes between
paulson
parents: 4653
diff changeset
  1014
			   if updated then
3083
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1015
				(*Backtrack at this level.
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1016
				  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
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1022
	      (*Try to close branch by unifying with head goal*)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1023
	      fun closeF [] = raise CLOSEF
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1024
		| closeF (L::Ls) = 
3083
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1025
		    case tryClose(G,L) of
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1026
			None     => closeF Ls
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1027
		      | Some tac => 
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1028
			    let val choices' = 
3092
b92a1b50b16b More tracing. hyp_subst_tac allowed to fail
paulson
parents: 3083
diff changeset
  1029
				    (if !trace then (prs"branch closed";
4065
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
  1030
						     traceVars sign ntrl)
3083
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1031
				               else ();
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1032
				     prune (nbrs, nxtVars, 
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1033
					    (ntrl, nbrs, PRV) :: choices))
4300
451ae21dca28 Statistics
paulson
parents: 4271
diff changeset
  1034
			    in  nclosed := !nclosed + 1;
451ae21dca28 Statistics
paulson
parents: 4271
diff changeset
  1035
				prv (tac::tacs, brs0::trs, choices', brs)  
3083
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1036
				handle PRV => 
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1037
				    (*reset Vars and try another literal
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1038
				      [this handler is pruned if possible!]*)
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1039
				 (clearTo ntrl;  closeF Ls)
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1040
			    end
11152
32d002362005 Blast bug fix: now always duplicates when applying a haz rule,
paulson
parents: 11119
diff changeset
  1041
	      (*Try to unify a queued formula (safe or haz) with head goal*)
2894
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
  1042
	      fun closeFl [] = raise CLOSEF
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
  1043
		| closeFl ((br, haz)::pairs) =
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
  1044
		    closeF (map fst br)
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
  1045
		      handle CLOSEF => closeF (map fst haz)
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
  1046
			handle CLOSEF => closeFl pairs
3083
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1047
	  in tracing sign brs0; 
4065
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
  1048
	     if lim<0 then (traceMsg "Limit reached.  "; backtrack choices)
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1049
	     else
4466
305390f23734 Better equality handling in Blast_tac, usingd a new variant of hyp_subst_tac
paulson
parents: 4391
diff changeset
  1050
	     prv (Data.hyp_subst_tac trace :: tacs, 
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1051
		  brs0::trs,  choices,
5463
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
  1052
		  equalSubst sign
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
  1053
		    (G, {pairs = (br,haz)::pairs, 
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
  1054
			 lits  = lits, vars  = vars, lim   = lim}) 
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
  1055
		    :: brs)
4065
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
  1056
	     handle DEST_EQ =>   closeF lits
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
  1057
	      handle CLOSEF =>   closeFl ((br,haz)::pairs)
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
  1058
	        handle CLOSEF => deeper rules
2894
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
  1059
		  handle NEWBRANCHES => 
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
  1060
		   (case netMkRules G vars hazList of
4466
305390f23734 Better equality handling in Blast_tac, usingd a new variant of hyp_subst_tac
paulson
parents: 4391
diff changeset
  1061
		       [] => (*there are no plausible haz rules*)
5463
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
  1062
			     (traceMsg "moving formula to literals";
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
  1063
			      prv (tacs, brs0::trs, choices,
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
  1064
				   {pairs = (br,haz)::pairs, 
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
  1065
				    lits  = addLit(G,lits), 
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
  1066
				    vars  = vars, 
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
  1067
				    lim   = lim}  :: brs))
2894
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
  1068
		    | _ => (*G admits some haz rules: try later*)
5463
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
  1069
			   (traceMsg "moving formula to haz list";
4466
305390f23734 Better equality handling in Blast_tac, usingd a new variant of hyp_subst_tac
paulson
parents: 4391
diff changeset
  1070
			    prv (if isGoal G then negOfGoal_tac :: tacs
5463
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
  1071
				             else tacs, 
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
  1072
				 brs0::trs,  
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
  1073
				 choices,
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
  1074
				 {pairs = (br, haz@[(negOfGoal G, md)])::pairs,
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
  1075
				  lits  = lits,
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
  1076
				  vars  = vars, 
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
  1077
				  lim   = lim}  :: brs)))
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1078
	  end
2924
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
  1079
       | prv (tacs, trs, choices, 
5463
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
  1080
	      {pairs = ([],haz)::(Gs,haz')::pairs, lits, vars, lim} :: brs) =
2894
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
  1081
	     (*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
  1082
	   prv (tacs, trs, choices, 
5463
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
  1083
		{pairs = (Gs,haz@haz')::pairs, 
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
  1084
		 lits  = lits, 
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
  1085
		 vars  = vars, 
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
  1086
		 lim    = lim} :: brs)
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1087
       | prv (tacs, trs, choices, 
5463
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
  1088
	      brs0 as {pairs = [([], (H,md)::Hs)],
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
  1089
		       lits, vars, lim} :: brs) =
2894
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
  1090
   	     (*no safe steps possible at any level: apply a haz rule*)
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1091
	  let exception PRV (*backtrack to precisely this recursion!*)
2894
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
  1092
	      val H = norm H
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1093
	      val ntrl = !ntrail
2924
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
  1094
	      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
  1095
	      (*new premises of haz rules may NOT be duplicated*)
4391
cc3e8453d7f0 More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents: 4354
diff changeset
  1096
	      fun newPrem (vars,P,dup,lim') prem = 
cc3e8453d7f0 More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents: 4354
diff changeset
  1097
		  let val Gs' = map (fn Q => (Q,false)) prem
3021
39806db47be9 Loop detection: before expanding a haz formula, see whether it is a duplicate
paulson
parents: 2999
diff changeset
  1098
		      and Hs' = if dup then Hs @ [(negOfGoal H, md)] else Hs
4196
9953c0995b79 Now applies "map negOfGoal" to lits when expanding haz rules.
paulson
parents: 4149
diff changeset
  1099
		      and lits' = if (exists isGoal prem) 
9953c0995b79 Now applies "map negOfGoal" to lits when expanding haz rules.
paulson
parents: 4149
diff changeset
  1100
			          then map negOfGoal lits
9953c0995b79 Now applies "map negOfGoal" to lits when expanding haz rules.
paulson
parents: 4149
diff changeset
  1101
				  else lits
5463
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
  1102
                  in  {pairs = if exists (match P) prem then [(Gs',Hs')] 
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
  1103
			       (*Recursive in this premise.  Don't make new
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
  1104
				 "stack frame".  New haz premises will end up
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
  1105
				 at the BACK of the queue, preventing
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
  1106
				 exclusion of others*)
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
  1107
			    else [(Gs',[]), ([],Hs')], 
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
  1108
		       lits = lits', 
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
  1109
		       vars = vars, 
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
  1110
		       lim  = lim'}
3021
39806db47be9 Loop detection: before expanding a haz formula, see whether it is a duplicate
paulson
parents: 2999
diff changeset
  1111
		  end
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1112
	      fun newBr x prems = map (newPrem x) prems  @  brs
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1113
	      (*Seek a matching rule.  If unifiable then add new premises
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1114
                to branch.*)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1115
	      fun deeper [] = raise NEWBRANCHES
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1116
		| deeper (((P,prems),tac)::grls) =
4065
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
  1117
		    if unify(add_term_vars(P,[]), P, H)
3083
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1118
		    then
5343
871b77df79a0 new version, more resistant to PROOF FAILED. Now it distinguishes between
paulson
parents: 4653
diff changeset
  1119
		     let val updated = ntrl < !ntrail (*branch updated*)
3083
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1120
			 val vars  = vars_in_vars vars
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1121
			 val vars' = foldr add_terms_vars (prems, vars)
11152
32d002362005 Blast bug fix: now always duplicates when applying a haz rule,
paulson
parents: 11119
diff changeset
  1122
			    (*duplicate H if md permits*)
32d002362005 Blast bug fix: now always duplicates when applying a haz rule,
paulson
parents: 11119
diff changeset
  1123
			 val dup = md (*earlier had "andalso vars' <> vars":
32d002362005 Blast bug fix: now always duplicates when applying a haz rule,
paulson
parents: 11119
diff changeset
  1124
                                  duplicate only if the subgoal has new vars*)
5463
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
  1125
			     (*any instances of P in the subgoals?
11152
32d002362005 Blast bug fix: now always duplicates when applying a haz rule,
paulson
parents: 11119
diff changeset
  1126
			       NB: boolean "recur" affects tracing only!*)
3083
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1127
			 and recur = exists (exists (match P)) prems
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1128
			 val lim' = (*Decrement "lim" extra if updates occur*)
5343
871b77df79a0 new version, more resistant to PROOF FAILED. Now it distinguishes between
paulson
parents: 4653
diff changeset
  1129
			     if updated then lim - (1+log(length rules))
3083
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1130
			     else lim-1 
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1131
				 (*It is tempting to leave "lim" UNCHANGED if
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1132
				   both dup and recur are false.  Proofs are
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1133
				   found at shallower depths, but looping
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1134
				   occurs too often...*)
3917
6ea5f9101c3e A lot of new comments
paulson
parents: 3533
diff changeset
  1135
			 val mayUndo = 
6ea5f9101c3e A lot of new comments
paulson
parents: 3533
diff changeset
  1136
			     (*Allowing backtracking from a rule application
6ea5f9101c3e A lot of new comments
paulson
parents: 3533
diff changeset
  1137
			       if other matching rules exist, if the rule
6ea5f9101c3e A lot of new comments
paulson
parents: 3533
diff changeset
  1138
			       updated variables, or if the rule did not
6ea5f9101c3e A lot of new comments
paulson
parents: 3533
diff changeset
  1139
			       introduce new variables.  This latter condition
6ea5f9101c3e A lot of new comments
paulson
parents: 3533
diff changeset
  1140
			       means it is not a standard "gamma-rule" but
6ea5f9101c3e A lot of new comments
paulson
parents: 3533
diff changeset
  1141
			       some other form of unsafe rule.  Aim is to
6ea5f9101c3e A lot of new comments
paulson
parents: 3533
diff changeset
  1142
			       emulate Fast_tac, which allows all unsafe steps
6ea5f9101c3e A lot of new comments
paulson
parents: 3533
diff changeset
  1143
			       to be undone.*)
6ea5f9101c3e A lot of new comments
paulson
parents: 3533
diff changeset
  1144
			     not(null grls)   (*other rules to try?*)
5343
871b77df79a0 new version, more resistant to PROOF FAILED. Now it distinguishes between
paulson
parents: 4653
diff changeset
  1145
			     orelse updated
3917
6ea5f9101c3e A lot of new comments
paulson
parents: 3533
diff changeset
  1146
			     orelse vars=vars'   (*no new Vars?*)
5481
c41956742c2e Less deterministic reconstruction: now more robust but perhaps slower
paulson
parents: 5463
diff changeset
  1147
			 val tac' = tac(updated, dup, true)
5463
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
  1148
		       (*if recur then perhaps shouldn't call rotate_tac: new
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
  1149
                         formulae should be last, but that's WRONG if the new
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
  1150
                         formulae are Goals, since they remain in the first
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
  1151
                         position*)
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
  1152
3083
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1153
		     in
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1154
		       if lim'<0 andalso not (null prems)
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1155
		       then (*it's faster to kill ALL the alternatives*)
5343
871b77df79a0 new version, more resistant to PROOF FAILED. Now it distinguishes between
paulson
parents: 4653
diff changeset
  1156
			   (traceMsg"Excessive branching: KILLED";
4065
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
  1157
			    clearTo ntrl;  raise NEWBRANCHES)
3083
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1158
		       else 
4391
cc3e8453d7f0 More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents: 4354
diff changeset
  1159
			 traceNew prems;  
11152
32d002362005 Blast bug fix: now always duplicates when applying a haz rule,
paulson
parents: 11119
diff changeset
  1160
			 if !trace andalso dup then prs" (duplicating)"
32d002362005 Blast bug fix: now always duplicates when applying a haz rule,
paulson
parents: 11119
diff changeset
  1161
					         else ();
4391
cc3e8453d7f0 More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents: 4354
diff changeset
  1162
			 if !trace andalso recur then prs" (recursive)"
cc3e8453d7f0 More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents: 4354
diff changeset
  1163
					         else ();
cc3e8453d7f0 More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents: 4354
diff changeset
  1164
			 traceVars sign ntrl;
4300
451ae21dca28 Statistics
paulson
parents: 4271
diff changeset
  1165
			 if null prems then nclosed := !nclosed + 1
451ae21dca28 Statistics
paulson
parents: 4271
diff changeset
  1166
			 else ntried := !ntried + length prems - 1;
4391
cc3e8453d7f0 More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents: 4354
diff changeset
  1167
			 prv(tac' :: tacs, 
3083
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1168
			     brs0::trs, 
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1169
			     (ntrl, length brs0, PRV) :: choices, 
4391
cc3e8453d7f0 More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents: 4354
diff changeset
  1170
			     newBr (vars', P, dup, lim') prems)
3083
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1171
			  handle PRV => 
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1172
			      if mayUndo
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1173
			      then (*reset Vars and try another rule*)
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1174
				   (clearTo ntrl;  deeper grls)
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1175
			      else (*backtrack to previous level*)
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1176
				   backtrack choices
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1177
		     end
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1178
		    else deeper grls
1a7edbd7f55a More tracing; less exception handling
paulson
parents: 3049
diff changeset
  1179
	  in tracing sign brs0; 
4065
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
  1180
	     if lim<1 then (traceMsg "Limit reached.  "; backtrack choices)
2924
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
  1181
	     else deeper rules
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1182
	     handle NEWBRANCHES => 
2894
d2ffee4f811b Re-organization of the order of haz rules
paulson
parents: 2883
diff changeset
  1183
		 (*cannot close branch: move H to literals*)
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1184
		 prv (tacs,  brs0::trs,  choices,
5463
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
  1185
		      {pairs = [([], Hs)], 
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
  1186
		       lits  = H::lits, 
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
  1187
		       vars  = vars, 
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
  1188
		       lim   = lim}  :: brs)
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1189
	  end
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1190
       | prv (tacs, trs, choices, _ :: brs) = backtrack choices
4065
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
  1191
 in init_gensym();
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
  1192
    prv ([], [], [(!ntrail, length brs, PROVE)], brs) 
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
  1193
 end;
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1194
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1195
2883
fd1c0b8e9b61 Now exports declConsts!
paulson
parents: 2854
diff changeset
  1196
(*Construct an initial branch.*)
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1197
fun initBranch (ts,lim) = 
5463
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
  1198
    {pairs = [(map (fn t => (t,true)) ts, [])],
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
  1199
     lits  = [], 
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
  1200
     vars  = add_terms_vars (ts,[]), 
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
  1201
     lim   = lim};
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1202
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1203
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1204
(*** Conversion & Skolemization of the Isabelle proof state ***)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1205
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1206
(*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
  1207
local open Term 
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1208
in
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1209
fun discard_foralls (Const("all",_)$Abs(a,T,t)) = discard_foralls t
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1210
  | discard_foralls t = t;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1211
end;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1212
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1213
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1214
(*List of variables not appearing as arguments to the given parameter*)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1215
fun getVars []                  i = []
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1216
  | getVars ((_,(v,is))::alist) i =
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1217
	if i mem is then getVars alist i
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1218
	else v :: getVars alist i;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1219
4233
85d004a96b98 Rationalized error handling: if low-level tactic (depth_tac) cannot accept the
paulson
parents: 4196
diff changeset
  1220
exception TRANS of string;
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1221
4233
85d004a96b98 Rationalized error handling: if low-level tactic (depth_tac) cannot accept the
paulson
parents: 4196
diff changeset
  1222
(*Translation of a subgoal: Skolemize all parameters*)
4065
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
  1223
fun fromSubgoal t =
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
  1224
  let val alistVar = ref []
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
  1225
      and alistTVar = ref []
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1226
      fun hdvar ((ix,(v,is))::_) = v
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1227
      fun from lev t =
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1228
	let val (ht,ts) = Term.strip_comb t
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1229
	    fun apply u = list_comb (u, map (from lev) ts)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1230
	    fun bounds [] = []
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1231
	      | bounds (Term.Bound i::ts) = 
4233
85d004a96b98 Rationalized error handling: if low-level tactic (depth_tac) cannot accept the
paulson
parents: 4196
diff changeset
  1232
		  if i<lev then raise TRANS
85d004a96b98 Rationalized error handling: if low-level tactic (depth_tac) cannot accept the
paulson
parents: 4196
diff changeset
  1233
		      "Function unknown's argument not a parameter"
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1234
		  else i-lev :: bounds ts
4233
85d004a96b98 Rationalized error handling: if low-level tactic (depth_tac) cannot accept the
paulson
parents: 4196
diff changeset
  1235
	      | bounds ts = raise TRANS
85d004a96b98 Rationalized error handling: if low-level tactic (depth_tac) cannot accept the
paulson
parents: 4196
diff changeset
  1236
		      "Function unknown's argument not a bound variable"
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1237
        in
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1238
	  case ht of 
4065
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
  1239
	      Term.Const aT    => apply (fromConst alistTVar aT)
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1240
	    | Term.Free  (a,_) => apply (Free a)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1241
	    | Term.Bound i     => apply (Bound i)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1242
	    | Term.Var (ix,_) => 
4065
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
  1243
		  (case (assoc_string_int(!alistVar,ix)) of
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
  1244
		       None => (alistVar := (ix, (ref None, bounds ts))
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
  1245
					  :: !alistVar;
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
  1246
				Var (hdvar(!alistVar)))
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1247
		     | Some(v,is) => if is=bounds ts then Var v
4233
85d004a96b98 Rationalized error handling: if low-level tactic (depth_tac) cannot accept the
paulson
parents: 4196
diff changeset
  1248
			    else raise TRANS
5411
7a43b484f6d2 fixed error msg
paulson
parents: 5343
diff changeset
  1249
				("Discrepancy among occurrences of "
4233
85d004a96b98 Rationalized error handling: if low-level tactic (depth_tac) cannot accept the
paulson
parents: 4196
diff changeset
  1250
				 ^ Syntax.string_of_vname ix))
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1251
	    | Term.Abs (a,_,body) => 
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1252
		  if null ts then Abs(a, from (lev+1) body)
4233
85d004a96b98 Rationalized error handling: if low-level tactic (depth_tac) cannot accept the
paulson
parents: 4196
diff changeset
  1253
		  else raise TRANS "argument not in normal form"
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1254
        end
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1255
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1256
      val npars = length (Logic.strip_params t)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1257
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1258
      (*Skolemize a subgoal from a proof state*)
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1259
      fun skoSubgoal i t =
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1260
	  if i<npars then 
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1261
	      skoSubgoal (i+1)
4065
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
  1262
		(subst_bound (Skolem (gensym "T_", getVars (!alistVar) i), 
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1263
			      t))
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1264
	  else t
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1265
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1266
  in  skoSubgoal 0 (from 0 (discard_foralls t))  end;
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1267
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1268
4300
451ae21dca28 Statistics
paulson
parents: 4271
diff changeset
  1269
fun initialize() = 
451ae21dca28 Statistics
paulson
parents: 4271
diff changeset
  1270
    (fullTrace:=[];  trail := [];  ntrail := 0;
451ae21dca28 Statistics
paulson
parents: 4271
diff changeset
  1271
     nclosed := 0;  ntried := 1);
451ae21dca28 Statistics
paulson
parents: 4271
diff changeset
  1272
451ae21dca28 Statistics
paulson
parents: 4271
diff changeset
  1273
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1274
(*Tactic using tableau engine and proof reconstruction.  
4391
cc3e8453d7f0 More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents: 4354
diff changeset
  1275
 "start" is CPU time at start, for printing SEARCH time
cc3e8453d7f0 More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents: 4354
diff changeset
  1276
	(also prints reconstruction time)
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1277
 "lim" is depth limit.*)
9486
2df511ebb956 handle actual object-logic rules by atomizing the goal;
wenzelm
parents: 9170
diff changeset
  1278
fun timing_depth_tac start cs lim i st0 = 
4323
561242f8606b Printing of statistics including time for search & reconstruction
paulson
parents: 4300
diff changeset
  1279
 (initialize();
10400
8621cb0021a6 tuned atomize_goal;
wenzelm
parents: 9779
diff changeset
  1280
  let val st = atomize_goal i st0;
9486
2df511ebb956 handle actual object-logic rules by atomizing the goal;
wenzelm
parents: 9170
diff changeset
  1281
      val {sign,...} = rep_thm st
4323
561242f8606b Printing of statistics including time for search & reconstruction
paulson
parents: 4300
diff changeset
  1282
      val skoprem = fromSubgoal (List.nth(prems_of st, i-1))
561242f8606b Printing of statistics including time for search & reconstruction
paulson
parents: 4300
diff changeset
  1283
      val hyps  = strip_imp_prems skoprem
561242f8606b Printing of statistics including time for search & reconstruction
paulson
parents: 4300
diff changeset
  1284
      and concl = strip_imp_concl skoprem
561242f8606b Printing of statistics including time for search & reconstruction
paulson
parents: 4300
diff changeset
  1285
      fun cont (tacs,_,choices) = 
561242f8606b Printing of statistics including time for search & reconstruction
paulson
parents: 4300
diff changeset
  1286
	  let val start = startTiming()
561242f8606b Printing of statistics including time for search & reconstruction
paulson
parents: 4300
diff changeset
  1287
	  in
561242f8606b Printing of statistics including time for search & reconstruction
paulson
parents: 4300
diff changeset
  1288
	  case Seq.pull(EVERY' (rev tacs) i st) of
561242f8606b Printing of statistics including time for search & reconstruction
paulson
parents: 4300
diff changeset
  1289
	      None => (writeln ("PROOF FAILED for depth " ^
561242f8606b Printing of statistics including time for search & reconstruction
paulson
parents: 4300
diff changeset
  1290
				Int.toString lim);
5463
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
  1291
		       if !trace then writeln "************************\n"
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
  1292
		       else ();
4323
561242f8606b Printing of statistics including time for search & reconstruction
paulson
parents: 4300
diff changeset
  1293
		       backtrack choices)
561242f8606b Printing of statistics including time for search & reconstruction
paulson
parents: 4300
diff changeset
  1294
	    | cell => (if (!trace orelse !stats)
561242f8606b Printing of statistics including time for search & reconstruction
paulson
parents: 4300
diff changeset
  1295
		       then writeln (endTiming start ^ " for reconstruction")
561242f8606b Printing of statistics including time for search & reconstruction
paulson
parents: 4300
diff changeset
  1296
		       else ();
561242f8606b Printing of statistics including time for search & reconstruction
paulson
parents: 4300
diff changeset
  1297
		       Seq.make(fn()=> cell))
561242f8606b Printing of statistics including time for search & reconstruction
paulson
parents: 4300
diff changeset
  1298
          end
4391
cc3e8453d7f0 More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents: 4354
diff changeset
  1299
  in prove (sign, start, cs, [initBranch (mkGoal concl :: hyps, lim)], cont) 
4323
561242f8606b Printing of statistics including time for search & reconstruction
paulson
parents: 4300
diff changeset
  1300
  end
561242f8606b Printing of statistics including time for search & reconstruction
paulson
parents: 4300
diff changeset
  1301
  handle PROVE     => Seq.empty);
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1302
4391
cc3e8453d7f0 More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents: 4354
diff changeset
  1303
(*Public version with fixed depth*)
cc3e8453d7f0 More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents: 4354
diff changeset
  1304
fun depth_tac cs lim i st = timing_depth_tac (startTiming()) cs lim i st;
cc3e8453d7f0 More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents: 4354
diff changeset
  1305
cc3e8453d7f0 More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents: 4354
diff changeset
  1306
fun blast_tac cs i st = 
5463
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
  1307
    ((DEEPEN (1,20) (timing_depth_tac (startTiming()) cs) 0) i 
a5479f5cd482 Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents: 5411
diff changeset
  1308
     THEN flexflex_tac) st
4391
cc3e8453d7f0 More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents: 4354
diff changeset
  1309
    handle TRANS s => (warning ("Blast_tac: " ^ s); Seq.empty);
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1310
4078
c107ab1c7626 adapted to new implicit claset mechanism;
wenzelm
parents: 4065
diff changeset
  1311
fun Blast_tac i = blast_tac (Data.claset()) i;
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1312
2924
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
  1313
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
  1314
(*** 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
  1315
     the resulting tactics, trace, etc.                            ***)
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
  1316
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
  1317
(*Translate subgoal i from a proof state*)
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
  1318
fun trygl cs lim i = 
4300
451ae21dca28 Statistics
paulson
parents: 4271
diff changeset
  1319
    (initialize();
2924
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
  1320
     let val st = topthm()
3030
04e3359921a8 Addition of printed tracing. Also some tidying
paulson
parents: 3021
diff changeset
  1321
         val {sign,...} = rep_thm st
4065
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
  1322
	 val skoprem = fromSubgoal (List.nth(prems_of st, i-1))
2924
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
  1323
         val hyps  = strip_imp_prems skoprem
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
  1324
         and concl = strip_imp_concl skoprem
4391
cc3e8453d7f0 More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents: 4354
diff changeset
  1325
     in timeap prove (sign, startTiming(), cs, 
cc3e8453d7f0 More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents: 4354
diff changeset
  1326
		      [initBranch (mkGoal concl :: hyps, lim)], I)
2924
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
  1327
     end
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
  1328
     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
  1329
4078
c107ab1c7626 adapted to new implicit claset mechanism;
wenzelm
parents: 4065
diff changeset
  1330
fun Trygl lim i = trygl (Data.claset()) lim i;
2924
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
  1331
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
  1332
(*Read a string to make an initial, singleton branch*)
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
  1333
fun readGoal sign s = read_cterm sign (s,propT) |>
4065
8862fcb5d44a New treatment of overloading\!
paulson
parents: 3917
diff changeset
  1334
                      term_of |> fromTerm |> rand |> mkGoal;
2924
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
  1335
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
  1336
fun tryInThy thy lim s = 
4300
451ae21dca28 Statistics
paulson
parents: 4271
diff changeset
  1337
    (initialize();
6391
0da748358eff Theory.sign_of;
wenzelm
parents: 5961
diff changeset
  1338
     timeap prove (Theory.sign_of thy, 
4391
cc3e8453d7f0 More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents: 4354
diff changeset
  1339
		   startTiming(), 
4323
561242f8606b Printing of statistics including time for search & reconstruction
paulson
parents: 4300
diff changeset
  1340
		   Data.claset(), 
6391
0da748358eff Theory.sign_of;
wenzelm
parents: 5961
diff changeset
  1341
		   [initBranch ([readGoal (Theory.sign_of thy) s], lim)], 
4323
561242f8606b Printing of statistics including time for search & reconstruction
paulson
parents: 4300
diff changeset
  1342
		   I));
2924
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
  1343
af506c35b4ed Control over excessive branching by applying a log2 penalty
paulson
parents: 2894
diff changeset
  1344
5926
58f9ca06b76b method setup;
wenzelm
parents: 5734
diff changeset
  1345
(** method setup **)
58f9ca06b76b method setup;
wenzelm
parents: 5734
diff changeset
  1346
7559
1d2c099e98f7 setup for refined facts handling;
wenzelm
parents: 7272
diff changeset
  1347
fun blast_args m =
11152
32d002362005 Blast bug fix: now always duplicates when applying a haz rule,
paulson
parents: 11119
diff changeset
  1348
  Method.bang_sectioned_args' 
32d002362005 Blast bug fix: now always duplicates when applying a haz rule,
paulson
parents: 11119
diff changeset
  1349
      Data.cla_modifiers (Scan.lift (Scan.option Args.nat)) m;
7155
70ba7d640bfe blast method: optional depth argument;
wenzelm
parents: 7003
diff changeset
  1350
9779
c71a1acffc27 Method.bang_sectioned_args';
wenzelm
parents: 9486
diff changeset
  1351
fun blast_meth None = Data.cla_meth' blast_tac
c71a1acffc27 Method.bang_sectioned_args';
wenzelm
parents: 9486
diff changeset
  1352
  | blast_meth (Some lim) = Data.cla_meth' (fn cs => depth_tac cs lim);
7155
70ba7d640bfe blast method: optional depth argument;
wenzelm
parents: 7003
diff changeset
  1353
11152
32d002362005 Blast bug fix: now always duplicates when applying a haz rule,
paulson
parents: 11119
diff changeset
  1354
val setup = [Method.add_methods [("blast", blast_args blast_meth, 
32d002362005 Blast bug fix: now always duplicates when applying a haz rule,
paulson
parents: 11119
diff changeset
  1355
				  "tableau prover")]];
5926
58f9ca06b76b method setup;
wenzelm
parents: 5734
diff changeset
  1356
58f9ca06b76b method setup;
wenzelm
parents: 5734
diff changeset
  1357
2854
f03b1652fc6a Implementation of blast_tac: fast tableau prover
paulson
parents:
diff changeset
  1358
end;