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(* Title: Provers/blast.ML 
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Author: Lawrence C Paulson, Cambridge University Computer Laboratory 
3083  3 
Copyright 1997 University of Cambridge 
2894  4 

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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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Given the typeargs system, constructor Const could be eliminated, with 
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TConst replaced by a constructor that takes the typargs list as an argument. 

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However, Const is heavily used for logical connectives. 

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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, ...); 
4651  17 
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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* rules must not require higherorder 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 
2894  23 

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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 newlycreated 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 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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signature BLAST_DATA = 

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sig 
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structure Classical: CLASSICAL 
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val thy: theory 
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val equality_name: string 
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val not_name: string 
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val notE: thm (* [ ~P; P ] ==> R *) 
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val ccontr: thm 

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val hyp_subst_tac: bool > int > tactic 

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end; 
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signature BLAST = 

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sig 
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exception TRANS of string (*reports translation errors*) 
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datatype term = 
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Const of string * term list 
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 Skolem of string * term option Unsynchronized.ref list 
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 Free of string 
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 Var of term option Unsynchronized.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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val depth_tac: Proof.context > int > int > tactic 
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val depth_limit: int Config.T 
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val blast_tac: Proof.context > int > tactic 
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val setup: theory > theory 
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(*debugging tools*) 
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type branch 
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val stats: bool Unsynchronized.ref 

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val trace: bool Unsynchronized.ref 

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val fullTrace: branch list list Unsynchronized.ref 

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val fromType: (indexname * term) list Unsynchronized.ref > Term.typ > term 

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val fromTerm: theory > Term.term > term 

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val fromSubgoal: theory > 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: Proof.context > string > term 
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val tryIt: Proof.context > int > string > 

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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; 
2854  82 

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functor Blast(Data: BLAST_DATA): BLAST = 
2854  84 
struct 
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42477  86 
structure Classical = Data.Classical; 
2854  87 

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val trace = Unsynchronized.ref false 
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and stats = Unsynchronized.ref false; (*for runtime and search statistics*) 

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datatype term = 
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Const of string * term list (*typargs constantas a terms!*) 
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 Skolem of string * term option Unsynchronized.ref list 
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 Free of string 
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 Var of term option Unsynchronized.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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(*Pending formulae carry md (may duplicate) flags*) 
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type branch = 
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{pairs: ((term*bool) list * (*safe formulae on this level*) 
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(term*bool) list) list, (*haz formulae on this level*) 
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lits: term list, (*literals: irreducible formulae*) 
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vars: term option Unsynchronized.ref list, (*variables occurring in branch*) 
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lim: int}; (*resource limit*) 
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(* global state information *) 
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datatype state = State of 
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{ctxt: Proof.context, 
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fullTrace: branch list list Unsynchronized.ref, 
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trail: term option Unsynchronized.ref list Unsynchronized.ref, 

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ntrail: int Unsynchronized.ref, 

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nclosed: int Unsynchronized.ref, 

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ntried: int Unsynchronized.ref} 

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fun reject_const thy c = 
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is_some (Sign.const_type thy c) andalso 
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error ("blast: theory contains illegal constant " ^ quote c); 
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fun initialize ctxt = 
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let 
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val thy = Proof_Context.theory_of ctxt; 
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val _ = reject_const thy "*Goal*"; 
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val _ = reject_const thy "*False*"; 
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in 
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State 
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{ctxt = ctxt, 
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fullTrace = Unsynchronized.ref [], 
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trail = Unsynchronized.ref [], 
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ntrail = Unsynchronized.ref 0, 
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nclosed = Unsynchronized.ref 0, (*number of branches closed during the search*) 
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ntried = Unsynchronized.ref 1} (*number of branches created by splitting (counting from 1)*) 
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end; 
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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 = Library.foldl (op $); 
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(* maps f(t1,...,tn) to (f, [t1,...,tn]) ; naturally tailrecursive*) 

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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 (Data.not_name, []) $ P; 
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fun isNot (Const (c, _) $ _) = c = Data.not_name 
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 isNot _ = false; 
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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 TruepropC = Object_Logic.judgment_name Data.thy; (* FIXME *) 
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val TruepropT = Sign.the_const_type Data.thy TruepropC; 
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fun mk_Trueprop t = Term.$ (Term.Const (TruepropC, TruepropT), t); 
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fun strip_Trueprop (tm as Const (c, _) $ t) = if c = TruepropC then t else tm 
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 strip_Trueprop tm = tm; 

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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, []), 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 (AList.lookup (op =) (!alist) ixn) of 
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NONE => let val t' = Var (Unsynchronized.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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fun fromConst thy alist (a, T) = 
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Const (a, map (fromType alist) (Sign.const_typargs thy (a, T))); 
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(*Tests whether 2 terms are alphaconvertible; chases instantiations*) 

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fun (Const (a, ts)) aconv (Const (b, us)) = a = b andalso aconvs (ts, us) 
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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 (Unsynchronized.ref(SOME t))) aconv u = t aconv u 

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 t aconv (Var (Unsynchronized.ref (SOME u))) = t aconv u 

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 (Var v) aconv (Var w) = v=w (*both Vars are unassigned*) 
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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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and aconvs ([], []) = true 

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 aconvs (t :: ts, u :: us) = t aconv u andalso aconvs (ts, us) 

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 aconvs _ = 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 Unsynchronized.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 Unsynchronized.ref NONE), vars) = ins_var (v, vars) 

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 add_term_vars (Var (Unsynchronized.ref (SOME u)), vars) = add_term_vars (u, vars) 

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 add_term_vars (Const (_, ts), vars) = add_terms_vars (ts, 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 (Unsynchronized.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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250 
(*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 nonlocal 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 
2854  259 
 incr_bv (inc, lev, Abs(a,body)) = Abs(a, incr_bv(inc,lev+1,body)) 
260 
 incr_bv (inc, lev, f$t) = incr_bv(inc,lev,f) $ incr_bv(inc,lev,t) 

261 
 incr_bv (inc, lev, u) = u; 

262 

263 
fun incr_boundvars 0 t = t 

264 
 incr_boundvars inc t = incr_bv(inc,0,t); 

265 

266 

267 
(*Accumulate all 'loose' bound vars referring to level 'lev' or beyond. 

268 
(Bound 0) is loose at level 0 *) 

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fun add_loose_bnos (Bound i, lev, js) = if i<lev then js 
20854  270 
else insert (op =) (i  lev) js 
2854  271 
 add_loose_bnos (Abs (_,t), lev, js) = add_loose_bnos (t, lev+1, js) 
272 
 add_loose_bnos (f$t, lev, js) = 

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add_loose_bnos (f, lev, add_loose_bnos (t, lev, js)) 
2854  274 
 add_loose_bnos (_, _, js) = js; 
275 

276 
fun loose_bnos t = add_loose_bnos (t, 0, []); 

277 

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fun subst_bound (arg, t) : term = 
2854  279 
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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282 
else Bound(i1) (*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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285 
 subst (t,lev) = t 
2854  286 
in subst (t,0) end; 
287 

288 

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(*Normalize...but not the bodies of ABSTRACTIONS*) 
2854  290 
fun norm t = case t of 
32740  291 
Skolem (a, args) => Skolem (a, vars_in_vars args) 
292 
 Const (a, ts) => Const (a, map norm ts) 

293 
 (Var (Unsynchronized.ref NONE)) => t 

294 
 (Var (Unsynchronized.ref (SOME u))) => norm u 

2854  295 
 (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) 
2854  298 
 _ => t; 
299 

300 

301 
(*Weak (onelevel) normalize for use in unification*) 

302 
fun wkNormAux t = case t of 

303 
(Var v) => (case !v of 

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SOME u => wkNorm u 
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 NONE => t) 
2854  306 
 (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) => (*etacontract if possible*) 
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(case wkNormAux body of 
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nb as (f $ t) => 
20664  312 
if member (op =) (loose_bnos f) 0 orelse wkNorm t <> Bound 0 
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313 
then Abs(a,nb) 
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314 
else wkNorm (incr_boundvars ~1 f) 
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315 
 nb => Abs (a,nb)) 
2854  316 
 _ => t 
317 
and wkNorm t = case head_of t of 

318 
Const _ => t 

319 
 Skolem(a,args) => t 

320 
 Free _ => t 

321 
 _ => wkNormAux t; 

322 

323 

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(*Does variable v occur in u? For unification. 
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325 
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 
15531  331 
(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) 
18177  334 
(*ignore Const, since term variables can't occur in types (?) *) 
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335 
 occ lev (Bound i) = lev <= i 
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336 
 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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338 
 occ lev _ = false; 
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339 
in occ 0 end; 
2854  340 

341 
exception UNIFY; 

342 

343 

344 
(*Restore the trail to some previous state: for backtracking*) 

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fun clearTo (State {ntrail, trail, ...}) n = 
3083  346 
while !ntrail<>n do 
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(hd(!trail) := NONE; 
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trail := tl (!trail); 
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ntrail := !ntrail  1); 
2854  350 

351 

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(*Firstorder unification with bound variables. 
2854  353 
"vars" is a list of variables local to the rule and NOT to be put 
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on the trail (no point in doing so) 
2854  355 
*) 
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356 
fun unify state (vars,t,u) = 
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357 
let val State {ntrail, trail, ...} = state 
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358 
val n = !ntrail 
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359 
fun update (t as Var v, u) = 
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360 
if t aconv u then () 
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361 
else if varOccur v u then raise UNIFY 
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362 
else if mem_var(v, vars) then v := SOME u 
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363 
else (*avoid updating Vars in the branch if possible!*) 
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364 
if is_Var u andalso mem_var(dest_Var u, vars) 
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365 
then dest_Var u := SOME t 
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366 
else (v := SOME u; 
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367 
trail := v :: !trail; ntrail := !ntrail + 1) 
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368 
fun unifyAux (t,u) = 
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369 
case (wkNorm t, wkNorm u) of 
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370 
(nt as Var v, nu) => update(nt,nu) 
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371 
 (nu, nt as Var v) => update(nt,nu) 
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372 
 (Const(a,ats), Const(b,bts)) => if a=b then unifysAux(ats,bts) 
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373 
else raise UNIFY 
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374 
 (Abs(_,t'), Abs(_,u')) => unifyAux(t',u') 
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375 
(*NB: can yield unifiers having dangling Bound vars!*) 
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376 
 (f$t', g$u') => (unifyAux(f,g); unifyAux(t',u')) 
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377 
 (nt, nu) => if nt aconv nu then () else raise UNIFY 
18177  378 
and unifysAux ([], []) = () 
379 
 unifysAux (t :: ts, u :: us) = (unifyAux (t, u); unifysAux (ts, us)) 

380 
 unifysAux _ = raise UNIFY; 

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381 
in (unifyAux(t,u); true) handle UNIFY => (clearTo state n; false) 
2854  382 
end; 
383 

384 

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385 
(*Convert from "real" terms to prototerms; etacontract. 
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386 
Code is similar to fromSubgoal.*) 
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387 
fun fromTerm thy t = 
32740  388 
let val alistVar = Unsynchronized.ref [] 
389 
and alistTVar = Unsynchronized.ref [] 

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390 
fun from (Term.Const aT) = fromConst thy alistTVar aT 
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391 
 from (Term.Free (a,_)) = Free a 
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392 
 from (Term.Bound i) = Bound i 
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393 
 from (Term.Var (ixn,T)) = 
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394 
(case (AList.lookup (op =) (!alistVar) ixn) of 
32740  395 
NONE => let val t' = Var (Unsynchronized.ref NONE) 
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396 
in alistVar := (ixn, t') :: !alistVar; t' 
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397 
end 
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398 
 SOME v => v) 
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399 
 from (Term.Abs (a,_,u)) = 
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400 
(case from u of 
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401 
u' as (f $ Bound 0) => 
20664  402 
if member (op =) (loose_bnos f) 0 then Abs(a,u') 
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403 
else incr_boundvars ~1 f 
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404 
 u' => Abs(a,u')) 
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405 
 from (Term.$ (f,u)) = from f $ from u 
2854  406 
in from t end; 
407 

4065  408 
(*A debugging function: replaces all Vars by dummy Frees for visual inspection 
409 
of whether they are distinct. Function revert undoes the assignments.*) 

410 
fun instVars t = 

32740  411 
let val name = Unsynchronized.ref "a" 
412 
val updated = Unsynchronized.ref [] 

18177  413 
fun inst (Const(a,ts)) = List.app inst ts 
32740  414 
 inst (Var(v as Unsynchronized.ref NONE)) = (updated := v :: (!updated); 
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415 
v := SOME (Free ("?" ^ !name)); 
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416 
name := Symbol.bump_string (!name)) 
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417 
 inst (Abs(a,t)) = inst t 
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418 
 inst (f $ u) = (inst f; inst u) 
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419 
 inst _ = () 
15570  420 
fun revert() = List.app (fn v => v:=NONE) (!updated) 
4065  421 
in inst t; revert end; 
422 

423 

2854  424 
(* A1==>...An==>B goes to [A1,...,An], where B is not an implication *) 
18177  425 
fun strip_imp_prems (Const ("==>", _) $ A $ B) = strip_Trueprop A :: strip_imp_prems B 
2854  426 
 strip_imp_prems _ = []; 
427 

428 
(* A1==>...An==>B goes to B, where B is not an implication *) 

18177  429 
fun strip_imp_concl (Const ("==>", _) $ A $ B) = strip_imp_concl B 
430 
 strip_imp_concl A = strip_Trueprop A; 

431 

2854  432 

433 

434 
(*** Conversion of Elimination Rules to Tableau Operations ***) 

435 

9170  436 
exception ElimBadConcl and ElimBadPrem; 
437 

438 
(*The conclusion becomes the goal/negated assumption *False*: delete it! 

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439 
If we don't find it then the premise is illformed and could cause 
9170  440 
PROOF FAILED*) 
441 
fun delete_concl [] = raise ElimBadPrem 

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442 
 delete_concl (P :: Ps) = 
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443 
(case P of 
32740  444 
Const (c, _) $ Var (Unsynchronized.ref (SOME (Const ("*False*", _)))) => 
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445 
if c = "*Goal*" orelse c = Data.not_name then Ps 
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446 
else P :: delete_concl Ps 
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447 
 _ => P :: delete_concl Ps); 
2854  448 

18177  449 
fun skoPrem vars (Const ("all", _) $ Abs (_, P)) = 
2854  450 
skoPrem vars (subst_bound (Skolem (gensym "S_", vars), P)) 
451 
 skoPrem vars P = P; 

452 

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453 
fun convertPrem t = 
9170  454 
delete_concl (mkGoal (strip_imp_concl t) :: strip_imp_prems t); 
2854  455 

456 
(*Expects elimination rules to have a formula variable as conclusion*) 

457 
fun convertRule vars t = 

458 
let val (P::Ps) = strip_imp_prems t 

459 
val Var v = strip_imp_concl t 

18177  460 
in v := SOME (Const ("*False*", [])); 
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461 
(P, map (convertPrem o skoPrem vars) Ps) 
9170  462 
end 
463 
handle Bind => raise ElimBadConcl; 

2854  464 

465 

466 
(*Like dup_elim, but puts the duplicated major premise FIRST*) 

31945  467 
fun rev_dup_elim th = (th RSN (2, revcut_rl)) > Thm.assumption 2 > Seq.hd; 
2854  468 

469 

4391
cc3e8453d7f0
More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents:
4354
diff
changeset

470 
(*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

471 
local 
cc3e8453d7f0
More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents:
4354
diff
changeset

472 
(*Count new hyps so that they can be rotated*) 
cc3e8453d7f0
More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents:
4354
diff
changeset

473 
fun nNewHyps [] = 0 
18177  474 
 nNewHyps (Const ("*Goal*", _) $ _ :: Ps) = nNewHyps Ps 
4391
cc3e8453d7f0
More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents:
4354
diff
changeset

475 
 nNewHyps (P::Ps) = 1 + nNewHyps Ps; 
2854  476 

5463
a5479f5cd482
Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents:
5411
diff
changeset

477 
fun rot_tac [] i st = Seq.single st 
4391
cc3e8453d7f0
More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents:
4354
diff
changeset

478 
 rot_tac (0::ks) i st = rot_tac ks (i+1) st 
31945  479 
 rot_tac (k::ks) i st = rot_tac ks (i+1) (Thm.rotate_rule (~k) i st); 
4391
cc3e8453d7f0
More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents:
4354
diff
changeset

480 
in 
cc3e8453d7f0
More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents:
4354
diff
changeset

481 
fun rot_subgoals_tac (rot, rl) = 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

482 
rot_tac (if rot then map nNewHyps rl else []) 
4391
cc3e8453d7f0
More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents:
4354
diff
changeset

483 
end; 
cc3e8453d7f0
More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents:
4354
diff
changeset

484 

2854  485 

32091
30e2ffbba718
proper context for Display.pretty_thm etc. or oldstyle versions Display.pretty_thm_global, Display.pretty_thm_without_context etc.;
wenzelm
parents:
31945
diff
changeset

486 
fun TRACE rl tac st i = 
30e2ffbba718
proper context for Display.pretty_thm etc. or oldstyle versions Display.pretty_thm_global, Display.pretty_thm_without_context etc.;
wenzelm
parents:
31945
diff
changeset

487 
if !trace then (writeln (Display.string_of_thm_without_context rl); tac st i) 
30e2ffbba718
proper context for Display.pretty_thm etc. or oldstyle versions Display.pretty_thm_global, Display.pretty_thm_without_context etc.;
wenzelm
parents:
31945
diff
changeset

488 
else tac st i; 
2854  489 

5343
871b77df79a0
new version, more resistant to PROOF FAILED. Now it distinguishes between
paulson
parents:
4653
diff
changeset

490 
(*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

491 
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

492 
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

493 
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

494 

18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

495 
(*Tableau rule from elimination rule. 
5343
871b77df79a0
new version, more resistant to PROOF FAILED. Now it distinguishes between
paulson
parents:
4653
diff
changeset

496 
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

497 
Flag "dup" requests duplication of the affected formula.*) 
42801
da4ad5f98953
proper Proof.context  eliminated global operations;
wenzelm
parents:
42793
diff
changeset

498 
fun fromRule ctxt vars rl = 
da4ad5f98953
proper Proof.context  eliminated global operations;
wenzelm
parents:
42793
diff
changeset

499 
let val thy = Proof_Context.theory_of ctxt 
da4ad5f98953
proper Proof.context  eliminated global operations;
wenzelm
parents:
42793
diff
changeset

500 
val trl = rl > Thm.prop_of > fromTerm thy > convertRule vars 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

501 
fun tac (upd, dup,rot) i = 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

502 
emtac upd (if dup then rev_dup_elim rl else rl) i 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

503 
THEN 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

504 
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

505 
in Option.SOME (trl, tac) end 
32091
30e2ffbba718
proper context for Display.pretty_thm etc. or oldstyle versions Display.pretty_thm_global, Display.pretty_thm_without_context etc.;
wenzelm
parents:
31945
diff
changeset

506 
handle 
30e2ffbba718
proper context for Display.pretty_thm etc. or oldstyle versions Display.pretty_thm_global, Display.pretty_thm_without_context etc.;
wenzelm
parents:
31945
diff
changeset

507 
ElimBadPrem => (*reject: prems don't preserve conclusion*) 
42801
da4ad5f98953
proper Proof.context  eliminated global operations;
wenzelm
parents:
42793
diff
changeset

508 
(warning ("Ignoring weak elimination rule\n" ^ Display.string_of_thm ctxt rl); 
32091
30e2ffbba718
proper context for Display.pretty_thm etc. or oldstyle versions Display.pretty_thm_global, Display.pretty_thm_without_context etc.;
wenzelm
parents:
31945
diff
changeset

509 
Option.NONE) 
30e2ffbba718
proper context for Display.pretty_thm etc. or oldstyle versions Display.pretty_thm_global, Display.pretty_thm_without_context etc.;
wenzelm
parents:
31945
diff
changeset

510 
 ElimBadConcl => (*ignore: conclusion is not just a variable*) 
30e2ffbba718
proper context for Display.pretty_thm etc. or oldstyle versions Display.pretty_thm_global, Display.pretty_thm_without_context etc.;
wenzelm
parents:
31945
diff
changeset

511 
(if !trace then 
30e2ffbba718
proper context for Display.pretty_thm etc. or oldstyle versions Display.pretty_thm_global, Display.pretty_thm_without_context etc.;
wenzelm
parents:
31945
diff
changeset

512 
(warning ("Ignoring illformed elimination rule:\n" ^ 
42801
da4ad5f98953
proper Proof.context  eliminated global operations;
wenzelm
parents:
42793
diff
changeset

513 
"conclusion should be a variable\n" ^ Display.string_of_thm ctxt rl)) 
32091
30e2ffbba718
proper context for Display.pretty_thm etc. or oldstyle versions Display.pretty_thm_global, Display.pretty_thm_without_context etc.;
wenzelm
parents:
31945
diff
changeset

514 
else (); 
30e2ffbba718
proper context for Display.pretty_thm etc. or oldstyle versions Display.pretty_thm_global, Display.pretty_thm_without_context etc.;
wenzelm
parents:
31945
diff
changeset

515 
Option.NONE); 
2854  516 

517 

3101
e8a92f497295
Again "norm" DOES NOT normalize bodies of abstractions
paulson
parents:
3092
diff
changeset

518 
(*** Conversion of Introduction Rules ***) 
2854  519 

520 
fun convertIntrPrem t = mkGoal (strip_imp_concl t) :: strip_imp_prems t; 

521 

522 
fun convertIntrRule vars t = 

523 
let val Ps = strip_imp_prems t 

524 
val P = strip_imp_concl t 

18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

525 
in (mkGoal P, map (convertIntrPrem o skoPrem vars) Ps) 
2854  526 
end; 
527 

18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

528 
(*Tableau rule from introduction rule. 
5343
871b77df79a0
new version, more resistant to PROOF FAILED. Now it distinguishes between
paulson
parents:
4653
diff
changeset

529 
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

530 
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

531 
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

532 
introduction rules.*) 
42801
da4ad5f98953
proper Proof.context  eliminated global operations;
wenzelm
parents:
42793
diff
changeset

533 
fun fromIntrRule ctxt vars rl = 
da4ad5f98953
proper Proof.context  eliminated global operations;
wenzelm
parents:
42793
diff
changeset

534 
let val thy = Proof_Context.theory_of ctxt 
da4ad5f98953
proper Proof.context  eliminated global operations;
wenzelm
parents:
42793
diff
changeset

535 
val trl = rl > Thm.prop_of > fromTerm thy > convertIntrRule vars 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

536 
fun tac (upd,dup,rot) i = 
42477  537 
rmtac upd (if dup then Classical.dup_intr rl else rl) i 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

538 
THEN 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

539 
rot_subgoals_tac (rot, #2 trl) i 
2854  540 
in (trl, tac) end; 
541 

542 

3030  543 
val dummyVar = Term.Var (("etc",0), dummyT); 
2854  544 

545 
(*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

546 
Ignore abstractions; identify all Vars; STOP at given depth*) 
af506c35b4ed
Control over excessive branching by applying a log2 penalty
paulson
parents:
2894
diff
changeset

547 
fun toTerm 0 _ = dummyVar 
18177  548 
 toTerm d (Const(a,_)) = Term.Const (a,dummyT) (*no need to convert typargs*) 
2924
af506c35b4ed
Control over excessive branching by applying a log2 penalty
paulson
parents:
2894
diff
changeset

549 
 toTerm d (Skolem(a,_)) = Term.Const (a,dummyT) 
af506c35b4ed
Control over excessive branching by applying a log2 penalty
paulson
parents:
2894
diff
changeset

550 
 toTerm d (Free a) = Term.Free (a,dummyT) 
af506c35b4ed
Control over excessive branching by applying a log2 penalty
paulson
parents:
2894
diff
changeset

551 
 toTerm d (Bound i) = Term.Bound i 
af506c35b4ed
Control over excessive branching by applying a log2 penalty
paulson
parents:
2894
diff
changeset

552 
 toTerm d (Var _) = dummyVar 
af506c35b4ed
Control over excessive branching by applying a log2 penalty
paulson
parents:
2894
diff
changeset

553 
 toTerm d (Abs(a,_)) = dummyVar 
af506c35b4ed
Control over excessive branching by applying a log2 penalty
paulson
parents:
2894
diff
changeset

554 
 toTerm d (f $ u) = Term.$ (toTerm d f, toTerm (d1) u); 
2854  555 

556 

42801
da4ad5f98953
proper Proof.context  eliminated global operations;
wenzelm
parents:
42793
diff
changeset

557 
fun netMkRules ctxt P vars (nps: netpair list) = 
2854  558 
case P of 
18177  559 
(Const ("*Goal*", _) $ G) => 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

560 
let val pG = mk_Trueprop (toTerm 2 G) 
19482
9f11af8f7ef9
tuned basic list operators (flat, maps, map_filter);
wenzelm
parents:
19037
diff
changeset

561 
val intrs = maps (fn (inet,_) => Net.unify_term inet pG) nps 
42801
da4ad5f98953
proper Proof.context  eliminated global operations;
wenzelm
parents:
42793
diff
changeset

562 
in map (fromIntrRule ctxt vars o #2) (order_list intrs) end 
2854  563 
 _ => 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

564 
let val pP = mk_Trueprop (toTerm 3 P) 
19482
9f11af8f7ef9
tuned basic list operators (flat, maps, map_filter);
wenzelm
parents:
19037
diff
changeset

565 
val elims = maps (fn (_,enet) => Net.unify_term enet pP) nps 
42801
da4ad5f98953
proper Proof.context  eliminated global operations;
wenzelm
parents:
42793
diff
changeset

566 
in map_filter (fromRule ctxt vars o #2) (order_list elims) end; 
3092  567 

568 

569 
(*Normalize a branchfor tracing*) 

570 
fun norm2 (G,md) = (norm G, md); 

571 

572 
fun normLev (Gs,Hs) = (map norm2 Gs, map norm2 Hs); 

573 

5463
a5479f5cd482
Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents:
5411
diff
changeset

574 
fun normBr {pairs, lits, vars, lim} = 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

575 
{pairs = map normLev pairs, 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

576 
lits = map norm lits, 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

577 
vars = vars, 
5463
a5479f5cd482
Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents:
5411
diff
changeset

578 
lim = lim}; 
3092  579 

580 

4065  581 
val dummyTVar = Term.TVar(("a",0), []); 
3092  582 
val dummyVar2 = Term.Var(("var",0), dummyT); 
583 

26938  584 
(*convert blast_tac's type representation to real types for tracing*) 
4065  585 
fun showType (Free a) = Term.TFree (a,[]) 
586 
 showType (Var _) = dummyTVar 

587 
 showType t = 

588 
(case strip_comb t of 

18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

589 
(Const (a, _), us) => Term.Type(a, map showType us) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

590 
 _ => dummyT); 
4065  591 

592 
(*Display toplevel overloading if any*) 

18177  593 
fun topType thy (Const (c, ts)) = SOME (Sign.const_instance thy (c, map showType ts)) 
594 
 topType thy (Abs(a,t)) = topType thy t 

595 
 topType thy (f $ u) = (case topType thy f of NONE => topType thy u  some => some) 

596 
 topType _ _ = NONE; 

4065  597 

598 

3092  599 
(*Convert from prototerms to ordinary terms with dummy types for tracing*) 
18177  600 
fun showTerm d (Const (a,_)) = Term.Const (a,dummyT) 
3092  601 
 showTerm d (Skolem(a,_)) = Term.Const (a,dummyT) 
32740  602 
 showTerm d (Free a) = Term.Free (a,dummyT) 
603 
 showTerm d (Bound i) = Term.Bound i 

604 
 showTerm d (Var (Unsynchronized.ref(SOME u))) = showTerm d u 

605 
 showTerm d (Var (Unsynchronized.ref NONE)) = dummyVar2 

3092  606 
 showTerm d (Abs(a,t)) = if d=0 then dummyVar 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

607 
else Term.Abs(a, dummyT, showTerm (d1) t) 
3092  608 
 showTerm d (f $ u) = if d=0 then dummyVar 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

609 
else Term.$ (showTerm d f, showTerm (d1) u); 
3092  610 

42801
da4ad5f98953
proper Proof.context  eliminated global operations;
wenzelm
parents:
42793
diff
changeset

611 
fun string_of ctxt d t = Syntax.string_of_term ctxt (showTerm d t); 
3092  612 

19037  613 
(*Convert a Goal to an ordinary Not. Used also in dup_intr, where a goal like 
614 
Ex(P) is duplicated as the assumption ~Ex(P). *) 

615 
fun negOfGoal (Const ("*Goal*", _) $ G) = negate G 

616 
 negOfGoal G = G; 

617 

618 
fun negOfGoal2 (G,md) = (negOfGoal G, md); 

619 

620 
(*Converts all Goals to Nots in the safe parts of a branch. They could 

621 
have been moved there from the literals list after substitution (equalSubst). 

622 
There can be at most onethis function could be made more efficient.*) 

623 
fun negOfGoals pairs = map (fn (Gs,haz) => (map negOfGoal2 Gs, haz)) pairs; 

624 

625 
(*Tactic. Convert *Goal* to negated assumption in FIRST position*) 

626 
fun negOfGoal_tac i = TRACE Data.ccontr (rtac Data.ccontr) i THEN 

627 
rotate_tac ~1 i; 

628 

42801
da4ad5f98953
proper Proof.context  eliminated global operations;
wenzelm
parents:
42793
diff
changeset

629 
fun traceTerm ctxt t = 
da4ad5f98953
proper Proof.context  eliminated global operations;
wenzelm
parents:
42793
diff
changeset

630 
let val thy = Proof_Context.theory_of ctxt 
da4ad5f98953
proper Proof.context  eliminated global operations;
wenzelm
parents:
42793
diff
changeset

631 
val t' = norm (negOfGoal t) 
da4ad5f98953
proper Proof.context  eliminated global operations;
wenzelm
parents:
42793
diff
changeset

632 
val stm = string_of ctxt 8 t' 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

633 
in 
24062
845c0d693328
explicit global state argument  no longer CRITICAL;
wenzelm
parents:
23985
diff
changeset

634 
case topType thy t' of 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

635 
NONE => stm (*no type to attach*) 
42801
da4ad5f98953
proper Proof.context  eliminated global operations;
wenzelm
parents:
42793
diff
changeset

636 
 SOME T => stm ^ "\t:: " ^ Syntax.string_of_typ ctxt T 
4065  637 
end; 
3092  638 

639 

640 
(*Print tracing information at each iteration of prover*) 

42801
da4ad5f98953
proper Proof.context  eliminated global operations;
wenzelm
parents:
42793
diff
changeset

641 
fun tracing (State {ctxt, fullTrace, ...}) brs = 
da4ad5f98953
proper Proof.context  eliminated global operations;
wenzelm
parents:
42793
diff
changeset

642 
let fun printPairs (((G,_)::_,_)::_) = Output.tracing (traceTerm ctxt G) 
da4ad5f98953
proper Proof.context  eliminated global operations;
wenzelm
parents:
42793
diff
changeset

643 
 printPairs (([],(H,_)::_)::_) = Output.tracing (traceTerm ctxt H ^ "\t (Unsafe)") 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

644 
 printPairs _ = () 
5463
a5479f5cd482
Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents:
5411
diff
changeset

645 
fun printBrs (brs0 as {pairs, lits, lim, ...} :: brs) = 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

646 
(fullTrace := brs0 :: !fullTrace; 
30320
5f859035331f
eliminated Output.immediate_output  violates the official message channel protocol;
wenzelm
parents:
30242
diff
changeset

647 
List.app (fn _ => Output.tracing "+") brs; 
41491  648 
Output.tracing (" [" ^ string_of_int lim ^ "] "); 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

649 
printPairs pairs; 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

650 
writeln"") 
3092  651 
in if !trace then printBrs (map normBr brs) else () 
652 
end; 

653 

5343
871b77df79a0
new version, more resistant to PROOF FAILED. Now it distinguishes between
paulson
parents:
4653
diff
changeset

654 
fun traceMsg s = if !trace then writeln s else (); 
4065  655 

3092  656 
(*Tracing: variables updated in the last branch operation?*) 
42801
da4ad5f98953
proper Proof.context  eliminated global operations;
wenzelm
parents:
42793
diff
changeset

657 
fun traceVars (State {ctxt, ntrail, trail, ...}) ntrl = 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

658 
if !trace then 
4065  659 
(case !ntrailntrl of 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

660 
0 => () 
30320
5f859035331f
eliminated Output.immediate_output  violates the official message channel protocol;
wenzelm
parents:
30242
diff
changeset

661 
 1 => Output.tracing "\t1 variable UPDATED:" 
41491  662 
 n => Output.tracing ("\t" ^ string_of_int n ^ " variables UPDATED:"); 
4065  663 
(*display the instantiations themselves, though no variable names*) 
42801
da4ad5f98953
proper Proof.context  eliminated global operations;
wenzelm
parents:
42793
diff
changeset

664 
List.app (fn v => Output.tracing (" " ^ string_of ctxt 4 (the (!v)))) 
4065  665 
(List.take(!trail, !ntrailntrl)); 
42801
da4ad5f98953
proper Proof.context  eliminated global operations;
wenzelm
parents:
42793
diff
changeset

666 
writeln "") 
3092  667 
else (); 
668 

669 
(*Tracing: how many new branches are created?*) 

670 
fun traceNew prems = 

18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

671 
if !trace then 
3092  672 
case length prems of 
30320
5f859035331f
eliminated Output.immediate_output  violates the official message channel protocol;
wenzelm
parents:
30242
diff
changeset

673 
0 => Output.tracing "branch closed by rule" 
5f859035331f
eliminated Output.immediate_output  violates the official message channel protocol;
wenzelm
parents:
30242
diff
changeset

674 
 1 => Output.tracing "branch extended (1 new subgoal)" 
41491  675 
 n => Output.tracing ("branch split: "^ string_of_int n ^ " new subgoals") 
3092  676 
else (); 
677 

678 

679 

2854  680 
(*** Code for handling equality: naive substitution, like hyp_subst_tac ***) 
681 

18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

682 
(*Replace the ATOMIC term "old" by "new" in t*) 
2854  683 
fun subst_atomic (old,new) t = 
32740  684 
let fun subst (Var(Unsynchronized.ref(SOME u))) = subst u 
685 
 subst (Abs(a,body)) = Abs(a, subst body) 

686 
 subst (f$t) = subst f $ subst t 

687 
 subst t = if t aconv old then new else t 

2854  688 
in subst t end; 
689 

690 
(*Etacontract a term from outside: just enough to reduce it to an atom*) 

18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

691 
fun eta_contract_atom (t0 as Abs(a, body)) = 
2854  692 
(case eta_contract2 body of 
20664  693 
f $ Bound 0 => if member (op =) (loose_bnos f) 0 then t0 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

694 
else eta_contract_atom (incr_boundvars ~1 f) 
2854  695 
 _ => t0) 
696 
 eta_contract_atom t = t 

697 
and eta_contract2 (f$t) = f $ eta_contract_atom t 

698 
 eta_contract2 t = eta_contract_atom t; 

699 

700 

701 
(*When can we safely delete the equality? 

702 
Not if it equates two constants; consider 0=1. 

703 
Not if it resembles x=t[x], since substitution does not eliminate x. 

704 
Not if it resembles ?x=0; another goal could instantiate ?x to Suc(i) 

705 
Prefer to eliminate Bound variables if possible. 

706 
Result: true = use as is, false = reorient first *) 

707 

18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

708 
(*Can t occur in u? For substitution. 
4354
7f4da01bdf0e
Fixed the treatment of substitution for equations, restricting occurrences of
paulson
parents:
4323
diff
changeset

709 
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

710 
REFLEXIVE because hyp_subst_tac fails on x=x.*) 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

711 
fun substOccur t = 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

712 
let (*NO vars are permitted in u except the arguments of t, if it is 
4354
7f4da01bdf0e
Fixed the treatment of substitution for equations, restricting occurrences of
paulson
parents:
4323
diff
changeset

713 
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

714 
be instantiated to a cycle. For example, x=?a is rejected because ?a 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

715 
could be instantiated to Suc(x).*) 
4354
7f4da01bdf0e
Fixed the treatment of substitution for equations, restricting occurrences of
paulson
parents:
4323
diff
changeset

716 
val vars = case t of 
7f4da01bdf0e
Fixed the treatment of substitution for equations, restricting occurrences of
paulson
parents:
4323
diff
changeset

717 
Skolem(_,vars) => vars 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

718 
 _ => [] 
4354
7f4da01bdf0e
Fixed the treatment of substitution for equations, restricting occurrences of
paulson
parents:
4323
diff
changeset

719 
fun occEq u = (t aconv u) orelse occ u 
32740  720 
and occ (Var(Unsynchronized.ref(SOME u))) = occEq u 
721 
 occ (Var v) = not (mem_var (v, vars)) 

722 
 occ (Abs(_,u)) = occEq u 

723 
 occ (f$u) = occEq u orelse occEq f 

724 
 occ _ = false; 

2854  725 
in occEq end; 
726 

3092  727 
exception DEST_EQ; 
728 

18177  729 
(*Take apart an equality. NO constant Trueprop*) 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

730 
fun dest_eq (Const (c, _) $ t $ u) = 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

731 
if c = Data.equality_name then (eta_contract_atom t, eta_contract_atom u) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

732 
else raise DEST_EQ 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

733 
 dest_eq _ = raise DEST_EQ; 
3092  734 

4196
9953c0995b79
Now applies "map negOfGoal" to lits when expanding haz rules.
paulson
parents:
4149
diff
changeset

735 
(*Reject the equality if u occurs in (or equals!) t*) 
2854  736 
fun check (t,u,v) = if substOccur t u then raise DEST_EQ else v; 
737 

18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

738 
(*IF the goal is an equality with a substitutable variable 
2854  739 
THEN orient that equality ELSE raise exception DEST_EQ*) 
3092  740 
fun orientGoal (t,u) = case (t,u) of 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

741 
(Skolem _, _) => check(t,u,(t,u)) (*eliminates t*) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

742 
 (_, Skolem _) => check(u,t,(u,t)) (*eliminates u*) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

743 
 (Free _, _) => check(t,u,(t,u)) (*eliminates t*) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

744 
 (_, Free _) => check(u,t,(u,t)) (*eliminates u*) 
2854  745 
 _ => raise DEST_EQ; 
746 

2894  747 
(*Substitute through the branch if an equality goal (else raise DEST_EQ). 
748 
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

749 
they should go: this could make proofs fail.*) 
42801
da4ad5f98953
proper Proof.context  eliminated global operations;
wenzelm
parents:
42793
diff
changeset

750 
fun equalSubst ctxt (G, {pairs, lits, vars, lim}) = 
3092  751 
let val (t,u) = orientGoal(dest_eq G) 
752 
val subst = subst_atomic (t,u) 

2854  753 
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

754 
(*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

755 
fun subForm ((G,md), (changed, pairs)) = 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

756 
let val nG = subst G 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

757 
in if nG aconv G then (changed, (G,md)::pairs) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

758 
else ((nG,md)::changed, pairs) 
2924
af506c35b4ed
Control over excessive branching by applying a log2 penalty
paulson
parents:
2894
diff
changeset

759 
end 
4466
305390f23734
Better equality handling in Blast_tac, usingd a new variant of hyp_subst_tac
paulson
parents:
4391
diff
changeset

760 
(*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

761 
fun subFrame ((Gs,Hs), (changed, frames)) = 
30190  762 
let val (changed', Gs') = List.foldr subForm (changed, []) Gs 
763 
val (changed'', Hs') = List.foldr subForm (changed', []) Hs 

4466
305390f23734
Better equality handling in Blast_tac, usingd a new variant of hyp_subst_tac
paulson
parents:
4391
diff
changeset

764 
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

765 
(*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

766 
fun subLit (lit, (changed, nlits)) = 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

767 
let val nlit = subst lit 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

768 
in if nlit aconv lit then (changed, nlit::nlits) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

769 
else ((nlit,true)::changed, nlits) 
2854  770 
end 
30190  771 
val (changed, lits') = List.foldr subLit ([], []) lits 
772 
val (changed', pairs') = List.foldr subFrame (changed, []) pairs 

42801
da4ad5f98953
proper Proof.context  eliminated global operations;
wenzelm
parents:
42793
diff
changeset

773 
in if !trace then writeln ("Substituting " ^ traceTerm ctxt u ^ 
da4ad5f98953
proper Proof.context  eliminated global operations;
wenzelm
parents:
42793
diff
changeset

774 
" for " ^ traceTerm ctxt t ^ " in branch" ) 
3092  775 
else (); 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

776 
{pairs = (changed',[])::pairs', (*affected formulas, and others*) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

777 
lits = lits', (*unaffected literals*) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

778 
vars = vars, 
5463
a5479f5cd482
Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents:
5411
diff
changeset

779 
lim = lim} 
2854  780 
end; 
781 

782 

783 
exception NEWBRANCHES and CLOSEF; 

784 

785 
exception PROVE; 

786 

4391
cc3e8453d7f0
More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents:
4354
diff
changeset

787 
(*Trying eq_contr_tac first INCREASES the effort, slowing reconstruction*) 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

788 
val contr_tac = ematch_tac [Data.notE] THEN' 
4391
cc3e8453d7f0
More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents:
4354
diff
changeset

789 
(eq_assume_tac ORELSE' assume_tac); 
2854  790 

4391
cc3e8453d7f0
More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents:
4354
diff
changeset

791 
val eContr_tac = TRACE Data.notE contr_tac; 
2854  792 
val eAssume_tac = TRACE asm_rl (eq_assume_tac ORELSE' assume_tac); 
793 

18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

794 
(*Try to unify complementary literals and return the corresponding tactic. *) 
24062
845c0d693328
explicit global state argument  no longer CRITICAL;
wenzelm
parents:
23985
diff
changeset

795 
fun tryClose state (G, L) = 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

796 
let 
24062
845c0d693328
explicit global state argument  no longer CRITICAL;
wenzelm
parents:
23985
diff
changeset

797 
fun close t u tac = if unify state ([], t, u) then SOME tac else NONE; 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

798 
fun arg (_ $ t) = t; 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

799 
in 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

800 
if isGoal G then close (arg G) L eAssume_tac 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

801 
else if isGoal L then close G (arg L) eAssume_tac 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

802 
else if isNot G then close (arg G) L eContr_tac 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

803 
else if isNot L then close G (arg L) eContr_tac 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

804 
else NONE 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

805 
end; 
2854  806 

807 
(*Were there Skolem terms in the premise? Must NOT chase Vars*) 

808 
fun hasSkolem (Skolem _) = true 

18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

809 
 hasSkolem (Abs (_,body)) = hasSkolem body 
42801
da4ad5f98953
proper Proof.context  eliminated global operations;
wenzelm
parents:
42793
diff
changeset

810 
 hasSkolem (f$t) = hasSkolem f orelse hasSkolem t 
2854  811 
 hasSkolem _ = false; 
812 

813 
(*Attach the right "may duplicate" flag to new formulae: if they contain 

814 
Skolem terms then allow duplication.*) 

815 
fun joinMd md [] = [] 

816 
 joinMd md (G::Gs) = (G, hasSkolem G orelse md) :: joinMd md Gs; 

817 

818 

819 
(** Backtracking and Pruning **) 

820 

821 
(*clashVar vars (n,trail) determines whether any of the last n elements 

822 
of "trail" occur in "vars" OR in their instantiations*) 

823 
fun clashVar [] = (fn _ => false) 

824 
 clashVar vars = 

825 
let fun clash (0, _) = false 

18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

826 
 clash (_, []) = false 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

827 
 clash (n, v::vs) = exists (varOccur v) vars orelse clash(n1,vs) 
2854  828 
in clash end; 
829 

830 

831 
(*nbrs = # of branches just prior to closing this one. Delete choice points 

832 
for goals proved by the latest inference, provided NO variables in the 

833 
next branch have been updated.*) 

24062
845c0d693328
explicit global state argument  no longer CRITICAL;
wenzelm
parents:
23985
diff
changeset

834 
fun prune _ (1, nxtVars, choices) = choices (*DON'T prune at very end: allow 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

835 
backtracking over bad proofs*) 
24062
845c0d693328
explicit global state argument  no longer CRITICAL;
wenzelm
parents:
23985
diff
changeset

836 
 prune (State {ntrail, trail, ...}) (nbrs: int, nxtVars, choices) = 
2854  837 
let fun traceIt last = 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

838 
let val ll = length last 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

839 
and lc = length choices 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

840 
in if !trace andalso ll<lc then 
41491  841 
(writeln("Pruning " ^ string_of_int(lcll) ^ " levels"); 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

842 
last) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

843 
else last 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

844 
end 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

845 
fun pruneAux (last, _, _, []) = last 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

846 
 pruneAux (last, ntrl, trl, (ntrl',nbrs',exn) :: choices) = 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

847 
if nbrs' < nbrs 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

848 
then last (*don't backtrack beyond first solution of goal*) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

849 
else if nbrs' > nbrs then pruneAux (last, ntrl, trl, choices) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

850 
else (* nbrs'=nbrs *) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

851 
if clashVar nxtVars (ntrlntrl', trl) then last 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

852 
else (*no clashes: can go back at least this far!*) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

853 
pruneAux(choices, ntrl', List.drop(trl, ntrlntrl'), 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

854 
choices) 
2854  855 
in traceIt (pruneAux (choices, !ntrail, !trail, choices)) end; 
856 

5463
a5479f5cd482
Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents:
5411
diff
changeset

857 
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

858 
 nextVars [] = []; 
2854  859 

18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

860 
fun backtrack (choices as (ntrl, nbrs, exn)::_) = 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

861 
(if !trace then (writeln ("Backtracking; now there are " ^ 
41491  862 
string_of_int nbrs ^ " branches")) 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

863 
else (); 
3083  864 
raise exn) 
865 
 backtrack _ = raise PROVE; 

2854  866 

2894  867 
(*Add the literal G, handling *Goal* and detecting duplicates.*) 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

868 
fun addLit (Const ("*Goal*", _) $ G, lits) = 
2894  869 
(*New literal is a *Goal*, so change all other Goals to Nots*) 
18177  870 
let fun bad (Const ("*Goal*", _) $ _) = true 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

871 
 bad (Const (c, _) $ G') = c = Data.not_name andalso G aconv G' 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

872 
 bad _ = false; 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

873 
fun change [] = [] 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

874 
 change (lit :: lits) = 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

875 
(case lit of 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

876 
Const (c, _) $ G' => 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

877 
if c = "*Goal*" orelse c = Data.not_name then 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

878 
if G aconv G' then change lits 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

879 
else negate G' :: change lits 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

880 
else lit :: change lits 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

881 
 _ => lit :: change lits) 
2854  882 
in 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

883 
Const ("*Goal*", []) $ G :: (if exists bad lits then change lits else lits) 
2854  884 
end 
885 
 addLit (G,lits) = ins_term(G, lits) 

886 

887 

2952  888 
(*For calculating the "penalty" to assess on a branching factor of n 
889 
log2 seems a little too severe*) 

3083  890 
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

891 

af506c35b4ed
Control over excessive branching by applying a log2 penalty
paulson
parents:
2894
diff
changeset

892 

3021
39806db47be9
Loop detection: before expanding a haz formula, see whether it is a duplicate
paulson
parents:
2999
diff
changeset

893 
(*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

894 
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

895 
fun match (Var _) u = true 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

896 
 match (Const (a,tas)) (Const (b,tbs)) = 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

897 
a = "*Goal*" andalso b = Data.not_name orelse 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

898 
a = Data.not_name andalso b = "*Goal*" orelse 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

899 
a = b andalso matchs tas tbs 
4065  900 
 match (Free a) (Free b) = (a=b) 
901 
 match (Bound i) (Bound j) = (i=j) 

902 
 match (Abs(_,t)) (Abs(_,u)) = match t u 

903 
 match (f$t) (g$u) = match f g andalso match t u 

18177  904 
 match t u = false 
905 
and matchs [] [] = true 

906 
 matchs (t :: ts) (u :: us) = match t u andalso matchs ts us; 

3021
39806db47be9
Loop detection: before expanding a haz formula, see whether it is a duplicate
paulson
parents:
2999
diff
changeset

907 

39806db47be9
Loop detection: before expanding a haz formula, see whether it is a duplicate
paulson
parents:
2999
diff
changeset

908 

24062
845c0d693328
explicit global state argument  no longer CRITICAL;
wenzelm
parents:
23985
diff
changeset

909 
fun printStats (State {ntried, nclosed, ...}) (b, start, tacs) = 
4323
561242f8606b
Printing of statistics including time for search & reconstruction
paulson
parents:
4300
diff
changeset

910 
if b then 
42012
2c3fe3cbebae
structure Timing: covers former start_timing/end_timing and Output.timeit etc;
wenzelm
parents:
41491
diff
changeset

911 
writeln (Timing.message (Timing.result start) ^ " for search. Closed: " 
41491  912 
^ string_of_int (!nclosed) ^ 
913 
" tried: " ^ string_of_int (!ntried) ^ 

914 
" tactics: " ^ string_of_int (length tacs)) 

4323
561242f8606b
Printing of statistics including time for search & reconstruction
paulson
parents:
4300
diff
changeset

915 
else (); 
561242f8606b
Printing of statistics including time for search & reconstruction
paulson
parents:
4300
diff
changeset

916 

561242f8606b
Printing of statistics including time for search & reconstruction
paulson
parents:
4300
diff
changeset

917 

18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

918 
(*Tableau prover based on leanTaP. Argument is a list of branches. Each 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

919 
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

920 
bound on unsafe expansions. 
cc3e8453d7f0
More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents:
4354
diff
changeset

921 
"start" is CPU time at start, for printing search time 
cc3e8453d7f0
More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents:
4354
diff
changeset

922 
*) 
42801
da4ad5f98953
proper Proof.context  eliminated global operations;
wenzelm
parents:
42793
diff
changeset

923 
fun prove (state, start, brs, cont) = 
da4ad5f98953
proper Proof.context  eliminated global operations;
wenzelm
parents:
42793
diff
changeset

924 
let val State {ctxt, ntrail, nclosed, ntried, ...} = state; 
42793  925 
val {safe0_netpair, safep_netpair, haz_netpair, ...} = 
926 
Classical.rep_cs (Classical.claset_of ctxt); 

2854  927 
val safeList = [safe0_netpair, safep_netpair] 
928 
and hazList = [haz_netpair] 

18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

929 
fun prv (tacs, trs, choices, []) = 
24062
845c0d693328
explicit global state argument  no longer CRITICAL;
wenzelm
parents:
23985
diff
changeset

930 
(printStats state (!trace orelse !stats, start, tacs); 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

931 
cont (tacs, trs, choices)) (*all branches closed!*) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

932 
 prv (tacs, trs, choices, 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

933 
brs0 as {pairs = ((G,md)::br, haz)::pairs, 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

934 
lits, vars, lim} :: brs) = 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

935 
(*apply a safe rule only (possibly allowing instantiation); 
3917  936 
defer any haz formulae*) 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

937 
let exception PRV (*backtrack to precisely this recursion!*) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

938 
val ntrl = !ntrail 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

939 
val nbrs = length brs0 
2854  940 
val nxtVars = nextVars brs 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

941 
val G = norm G 
42801
da4ad5f98953
proper Proof.context  eliminated global operations;
wenzelm
parents:
42793
diff
changeset

942 
val rules = netMkRules ctxt G vars safeList 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

943 
(*Make a new branch, decrementing "lim" if instantiations occur*) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

944 
fun newBr (vars',lim') prems = 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

945 
map (fn prem => 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

946 
if (exists isGoal prem) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

947 
then {pairs = ((joinMd md prem, []) :: 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

948 
negOfGoals ((br, haz)::pairs)), 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

949 
lits = map negOfGoal lits, 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

950 
vars = vars', 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

951 
lim = lim'} 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

952 
else {pairs = ((joinMd md prem, []) :: 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

953 
(br, haz) :: pairs), 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

954 
lits = lits, 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

955 
vars = vars', 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

956 
lim = lim'}) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

957 
prems @ 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

958 
brs 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

959 
(*Seek a matching rule. If unifiable then add new premises 
2854  960 
to branch.*) 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

961 
fun deeper [] = raise NEWBRANCHES 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

962 
 deeper (((P,prems),tac)::grls) = 
24062
845c0d693328
explicit global state argument  no longer CRITICAL;
wenzelm
parents:
23985
diff
changeset

963 
if unify state (add_term_vars(P,[]), P, G) 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

964 
then (*P comes from the rule; G comes from the branch.*) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

965 
let val updated = ntrl < !ntrail (*branch updated*) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

966 
val lim' = if updated 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

967 
then lim  (1+log(length rules)) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

968 
else lim (*discourage branching updates*) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

969 
val vars = vars_in_vars vars 
30190  970 
val vars' = List.foldr add_terms_vars vars prems 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

971 
val choices' = (ntrl, nbrs, PRV) :: choices 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

972 
val tacs' = (tac(updated,false,true)) 
5343
871b77df79a0
new version, more resistant to PROOF FAILED. Now it distinguishes between
paulson
parents:
4653
diff
changeset

973 
:: tacs (*no duplication; rotate*) 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

974 
in 
24062
845c0d693328
explicit global state argument  no longer CRITICAL;
wenzelm
parents:
23985
diff
changeset

975 
traceNew prems; traceVars state ntrl; 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

976 
(if null prems then (*closed the branch: prune!*) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

977 
(nclosed := !nclosed + 1; 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

978 
prv(tacs', brs0::trs, 
24062
845c0d693328
explicit global state argument  no longer CRITICAL;
wenzelm
parents:
23985
diff
changeset

979 
prune state (nbrs, nxtVars, choices'), 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

980 
brs)) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

981 
else (*prems nonnull*) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

982 
if lim'<0 (*faster to kill ALL the alternatives*) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

983 
then (traceMsg"Excessive branching: KILLED"; 
24062
845c0d693328
explicit global state argument  no longer CRITICAL;
wenzelm
parents:
23985
diff
changeset

984 
clearTo state ntrl; raise NEWBRANCHES) 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

985 
else 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

986 
(ntried := !ntried + length prems  1; 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

987 
prv(tacs', brs0::trs, choices', 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

988 
newBr (vars',lim') prems))) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

989 
handle PRV => 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

990 
if updated then 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

991 
(*Backtrack at this level. 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

992 
Reset Vars and try another rule*) 
24062
845c0d693328
explicit global state argument  no longer CRITICAL;
wenzelm
parents:
23985
diff
changeset

993 
(clearTo state ntrl; deeper grls) 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

994 
else (*backtrack to previous level*) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

995 
backtrack choices 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

996 
end 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

997 
else deeper grls 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

998 
(*Try to close branch by unifying with head goal*) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

999 
fun closeF [] = raise CLOSEF 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1000 
 closeF (L::Ls) = 
24062
845c0d693328
explicit global state argument  no longer CRITICAL;
wenzelm
parents:
23985
diff
changeset

1001 
case tryClose state (G,L) of 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1002 
NONE => closeF Ls 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1003 
 SOME tac => 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1004 
let val choices' = 
30320
5f859035331f
eliminated Output.immediate_output  violates the official message channel protocol;
wenzelm
parents:
30242
diff
changeset

1005 
(if !trace then (Output.tracing "branch closed"; 
24062
845c0d693328
explicit global state argument  no longer CRITICAL;
wenzelm
parents:
23985
diff
changeset

1006 
traceVars state ntrl) 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1007 
else (); 
24062
845c0d693328
explicit global state argument  no longer CRITICAL;
wenzelm
parents:
23985
diff
changeset

1008 
prune state (nbrs, nxtVars, 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1009 
(ntrl, nbrs, PRV) :: choices)) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1010 
in nclosed := !nclosed + 1; 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1011 
prv (tac::tacs, brs0::trs, choices', brs) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1012 
handle PRV => 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1013 
(*reset Vars and try another literal 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1014 
[this handler is pruned if possible!]*) 
24062
845c0d693328
explicit global state argument  no longer CRITICAL;
wenzelm
parents:
23985
diff
changeset

1015 
(clearTo state ntrl; closeF Ls) 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1016 
end 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1017 
(*Try to unify a queued formula (safe or haz) with head goal*) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1018 
fun closeFl [] = raise CLOSEF 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1019 
 closeFl ((br, haz)::pairs) = 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1020 
closeF (map fst br) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1021 
handle CLOSEF => closeF (map fst haz) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1022 
handle CLOSEF => closeFl pairs 
24062
845c0d693328
explicit global state argument  no longer CRITICAL;
wenzelm
parents:
23985
diff
changeset

1023 
in tracing state brs0; 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1024 
if lim<0 then (traceMsg "Limit reached. "; backtrack choices) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1025 
else 
23908  1026 
prv (Data.hyp_subst_tac (!trace) :: tacs, 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1027 
brs0::trs, choices, 
42801
da4ad5f98953
proper Proof.context  eliminated global operations;
wenzelm
parents:
42793
diff
changeset

1028 
equalSubst ctxt 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1029 
(G, {pairs = (br,haz)::pairs, 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1030 
lits = lits, vars = vars, lim = lim}) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1031 
:: brs) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1032 
handle DEST_EQ => closeF lits 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1033 
handle CLOSEF => closeFl ((br,haz)::pairs) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1034 
handle CLOSEF => deeper rules 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1035 
handle NEWBRANCHES => 
42801
da4ad5f98953
proper Proof.context  eliminated global operations;
wenzelm
parents:
42793
diff
changeset

1036 
(case netMkRules ctxt G vars hazList of 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1037 
[] => (*there are no plausible haz rules*) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1038 
(traceMsg "moving formula to literals"; 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1039 
prv (tacs, brs0::trs, choices, 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1040 
{pairs = (br,haz)::pairs, 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1041 
lits = addLit(G,lits), 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1042 
vars = vars, 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1043 
lim = lim} :: brs)) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1044 
 _ => (*G admits some haz rules: try later*) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1045 
(traceMsg "moving formula to haz list"; 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1046 
prv (if isGoal G then negOfGoal_tac :: tacs 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1047 
else tacs, 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1048 
brs0::trs, 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1049 
choices, 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1050 
{pairs = (br, haz@[(negOfGoal G, md)])::pairs, 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1051 
lits = lits, 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1052 
vars = vars, 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1053 
lim = lim} :: brs))) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1054 
end 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1055 
 prv (tacs, trs, choices, 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1056 
{pairs = ([],haz)::(Gs,haz')::pairs, lits, vars, lim} :: brs) = 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1057 
(*no more "safe" formulae: transfer haz down a level*) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1058 
prv (tacs, trs, choices, 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1059 
{pairs = (Gs,haz@haz')::pairs, 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1060 
lits = lits, 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1061 
vars = vars, 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1062 
lim = lim} :: brs) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1063 
 prv (tacs, trs, choices, 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1064 
brs0 as {pairs = [([], (H,md)::Hs)], 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1065 
lits, vars, lim} :: brs) = 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1066 
(*no safe steps possible at any level: apply a haz rule*) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1067 
let exception PRV (*backtrack to precisely this recursion!*) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1068 
val H = norm H 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1069 
val ntrl = !ntrail 
42801
da4ad5f98953
proper Proof.context  eliminated global operations;
wenzelm
parents:
42793
diff
changeset

1070 
val rules = netMkRules ctxt H vars hazList 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1071 
(*new premises of haz rules may NOT be duplicated*) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1072 
fun newPrem (vars,P,dup,lim') prem = 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1073 
let val Gs' = map (fn Q => (Q,false)) prem 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1074 
and Hs' = if dup then Hs @ [(negOfGoal H, md)] else Hs 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1075 
and lits' = if (exists isGoal prem) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1076 
then map negOfGoal lits 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1077 
else lits 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1078 
in {pairs = if exists (match P) prem then [(Gs',Hs')] 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1079 
(*Recursive in this premise. Don't make new 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1080 
"stack frame". New haz premises will end up 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1081 
at the BACK of the queue, preventing 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1082 
exclusion of others*) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1083 
else [(Gs',[]), ([],Hs')], 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1084 
lits = lits', 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1085 
vars = vars, 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1086 
lim = lim'} 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1087 
end 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1088 
fun newBr x prems = map (newPrem x) prems @ brs 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1089 
(*Seek a matching rule. If unifiable then add new premises 
2854  1090 
to branch.*) 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1091 
fun deeper [] = raise NEWBRANCHES 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1092 
 deeper (((P,prems),tac)::grls) = 
24062
845c0d693328
explicit global state argument  no longer CRITICAL;
wenzelm
parents:
23985
diff
changeset

1093 
if unify state (add_term_vars(P,[]), P, H) 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1094 
then 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1095 
let val updated = ntrl < !ntrail (*branch updated*) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1096 
val vars = vars_in_vars vars 
30190  1097 
val vars' = List.foldr add_terms_vars vars prems 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1098 
(*duplicate H if md permits*) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1099 
val dup = md (*earlier had "andalso vars' <> vars": 
11152
32d002362005
Blast bug fix: now always duplicates when applying a haz rule,
paulson
parents:
11119
diff
changeset

1100 
duplicate only if the subgoal has new vars*) 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1101 
(*any instances of P in the subgoals? 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1102 
NB: boolean "recur" affects tracing only!*) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1103 
and recur = exists (exists (match P)) prems 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1104 
val lim' = (*Decrement "lim" extra if updates occur*) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1105 
if updated then lim  (1+log(length rules)) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1106 
else lim1 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1107 
(*It is tempting to leave "lim" UNCHANGED if 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1108 
both dup and recur are false. Proofs are 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1109 
found at shallower depths, but looping 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1110 
occurs too often...*) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1111 
val mayUndo = 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1112 
(*Allowing backtracking from a rule application 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1113 
if other matching rules exist, if the rule 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1114 
updated variables, or if the rule did not 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1115 
introduce new variables. This latter condition 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1116 
means it is not a standard "gammarule" but 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1117 
some other form of unsafe rule. Aim is to 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1118 
emulate Fast_tac, which allows all unsafe steps 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1119 
to be undone.*) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1120 
not(null grls) (*other rules to try?*) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1121 
orelse updated 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1122 
orelse vars=vars' (*no new Vars?*) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1123 
val tac' = tac(updated, dup, true) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1124 
(*if recur then perhaps shouldn't call rotate_tac: new 
5463
a5479f5cd482
Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents:
5411
diff
changeset

1125 
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

1126 
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

1127 
position*) 
a5479f5cd482
Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents:
5411
diff
changeset

1128 

18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1129 
in 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1130 
if lim'<0 andalso not (null prems) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1131 
then (*it's faster to kill ALL the alternatives*) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1132 
(traceMsg"Excessive branching: KILLED"; 
24062
845c0d693328
explicit global state argument  no longer CRITICAL;
wenzelm
parents:
23985
diff
changeset

1133 
clearTo state ntrl; raise NEWBRANCHES) 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1134 
else 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1135 
traceNew prems; 
30320
5f859035331f
eliminated Output.immediate_output  violates the official message channel protocol;
wenzelm
parents:
30242
diff
changeset

1136 
if !trace andalso dup then Output.tracing " (duplicating)" 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1137 
else (); 
30320
5f859035331f
eliminated Output.immediate_output  violates the official message channel protocol;
wenzelm
parents:
30242
diff
changeset

1138 
if !trace andalso recur then Output.tracing " (recursive)" 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1139 
else (); 
24062
845c0d693328
explicit global state argument  no longer CRITICAL;
wenzelm
parents:
23985
diff
changeset

1140 
traceVars state ntrl; 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1141 
if null prems then nclosed := !nclosed + 1 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1142 
else ntried := !ntried + length prems  1; 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1143 
prv(tac' :: tacs, 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1144 
brs0::trs, 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1145 
(ntrl, length brs0, PRV) :: choices, 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1146 
newBr (vars', P, dup, lim') prems) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1147 
handle PRV => 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1148 
if mayUndo 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1149 
then (*reset Vars and try another rule*) 
24062
845c0d693328
explicit global state argument  no longer CRITICAL;
wenzelm
parents:
23985
diff
changeset

1150 
(clearTo state ntrl; deeper grls) 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1151 
else (*backtrack to previous level*) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1152 
backtrack choices 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1153 
end 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1154 
else deeper grls 
24062
845c0d693328
explicit global state argument  no longer CRITICAL;
wenzelm
parents:
23985
diff
changeset

1155 
in tracing state brs0; 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1156 
if lim<1 then (traceMsg "Limit reached. "; backtrack choices) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1157 
else deeper rules 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1158 
handle NEWBRANCHES => 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1159 
(*cannot close branch: move H to literals*) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1160 
prv (tacs, brs0::trs, choices, 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1161 
{pairs = [([], Hs)], 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1162 
lits = H::lits, 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1163 
vars = vars, 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1164 
lim = lim} :: brs) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1165 
end 
2854  1166 
 prv (tacs, trs, choices, _ :: brs) = backtrack choices 
12346  1167 
in prv ([], [], [(!ntrail, length brs, PROVE)], brs) end; 
2854  1168 

1169 

2883  1170 
(*Construct an initial branch.*) 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1171 
fun initBranch (ts,lim) = 
5463
a5479f5cd482
Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents:
5411
diff
changeset

1172 
{pairs = [(map (fn t => (t,true)) ts, [])], 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1173 
lits = [], 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1174 
vars = add_terms_vars (ts,[]), 
5463
a5479f5cd482
Allows more backtracking in proof reconstruction, making it slower but more
paulson
parents:
5411
diff
changeset

1175 
lim = lim}; 
2854  1176 

1177 

1178 
(*** Conversion & Skolemization of the Isabelle proof state ***) 

1179 

1180 
(*Make a list of all the parameters in a subgoal, even if nested*) 

18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1181 
local open Term 
2854  1182 
in 
1183 
fun discard_foralls (Const("all",_)$Abs(a,T,t)) = discard_foralls t 

1184 
 discard_foralls t = t; 

1185 
end; 

1186 

1187 
(*List of variables not appearing as arguments to the given parameter*) 

1188 
fun getVars [] i = [] 

20664  1189 
 getVars ((_,(v,is))::alist) (i: int) = 
1190 
if member (op =) is i then getVars alist i 

18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1191 
else v :: getVars alist i; 
2854  1192 

4233
85d004a96b98
Rationalized error handling: if lowlevel tactic (depth_tac) cannot accept the
paulson
parents:
4196
diff
changeset

1193 
exception TRANS of string; 
2854  1194 

4233
85d004a96b98
Rationalized error handling: if lowlevel tactic (depth_tac) cannot accept the
paulson
parents:
4196
diff
changeset

1195 
(*Translation of a subgoal: Skolemize all parameters*) 
24062
845c0d693328
explicit global state argument  no longer CRITICAL;
wenzelm
parents:
23985
diff
changeset

1196 
fun fromSubgoal thy t = 
32740  1197 
let val alistVar = Unsynchronized.ref [] 
1198 
and alistTVar = Unsynchronized.ref [] 

2854  1199 
fun hdvar ((ix,(v,is))::_) = v 
1200 
fun from lev t = 

18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1201 
let val (ht,ts) = Term.strip_comb t 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1202 
fun apply u = list_comb (u, map (from lev) ts) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1203 
fun bounds [] = [] 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1204 
 bounds (Term.Bound i::ts) = 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1205 
if i<lev then raise TRANS 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1206 
"Function unknown's argument not a parameter" 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1207 
else ilev :: bounds ts 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1208 
 bounds ts = raise TRANS 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1209 
"Function unknown's argument not a bound variable" 
2854  1210 
in 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1211 
case ht of 
24062
845c0d693328
explicit global state argument  no longer CRITICAL;
wenzelm
parents:
23985
diff
changeset

1212 
Term.Const aT => apply (fromConst thy alistTVar aT) 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1213 
 Term.Free (a,_) => apply (Free a) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1214 
 Term.Bound i => apply (Bound i) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1215 
 Term.Var (ix,_) => 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1216 
(case (AList.lookup (op =) (!alistVar) ix) of 
32740  1217 
NONE => (alistVar := (ix, (Unsynchronized.ref NONE, bounds ts)) 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1218 
:: !alistVar; 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1219 
Var (hdvar(!alistVar))) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1220 
 SOME(v,is) => if is=bounds ts then Var v 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1221 
else raise TRANS 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1222 
("Discrepancy among occurrences of " 
22678  1223 
^ Term.string_of_vname ix)) 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1224 
 Term.Abs (a,_,body) => 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1225 
if null ts then Abs(a, from (lev+1) body) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1226 
else raise TRANS "argument not in normal form" 
2854  1227 
end 
1228 

1229 
val npars = length (Logic.strip_params t) 

1230 

1231 
(*Skolemize a subgoal from a proof state*) 

1232 
fun skoSubgoal i t = 

18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1233 
if i<npars then 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1234 
skoSubgoal (i+1) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1235 
(subst_bound (Skolem (gensym "T_", getVars (!alistVar) i), 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1236 
t)) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1237 
else t 
2854  1238 

1239 
in skoSubgoal 0 (from 0 (discard_foralls t)) end; 

1240 

1241 

18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1242 
(*Tactic using tableau engine and proof reconstruction. 
4391
cc3e8453d7f0
More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents:
4354
diff
changeset

1243 
"start" is CPU time at start, for printing SEARCH time 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1244 
(also prints reconstruction time) 
2854  1245 
"lim" is depth limit.*) 
42793  1246 
fun timing_depth_tac start ctxt lim i st0 = 
42801
da4ad5f98953
proper Proof.context  eliminated global operations;
wenzelm
parents:
42793
diff
changeset

1247 
let val thy = Proof_Context.theory_of ctxt 
da4ad5f98953
proper Proof.context  eliminated global operations;
wenzelm
parents:
42793
diff
changeset

1248 
val state = initialize ctxt 
42369  1249 
val st = st0 
1250 
> rotate_prems (i  1) 

1251 
> Conv.gconv_rule Object_Logic.atomize_prems 1 

1252 
val skoprem = fromSubgoal thy (#1 (Logic.dest_implies (Thm.prop_of st))) 

4323
561242f8606b
Printing of statistics including time for search & reconstruction
paulson
parents:
4300
diff
changeset

1253 
val hyps = strip_imp_prems skoprem 
561242f8606b
Printing of statistics including time for search & reconstruction
paulson
parents:
4300
diff
changeset

1254 
and concl = strip_imp_concl skoprem 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1255 
fun cont (tacs,_,choices) = 
42012
2c3fe3cbebae
structure Timing: covers former start_timing/end_timing and Output.timeit etc;
wenzelm
parents:
41491
diff
changeset

1256 
let val start = Timing.start () 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1257 
in 
42369  1258 
case Seq.pull(EVERY' (rev tacs) 1 st) of 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1259 
NONE => (writeln ("PROOF FAILED for depth " ^ 
41491  1260 
string_of_int lim); 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1261 
if !trace then error "************************\n" 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1262 
else (); 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1263 
backtrack choices) 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1264 
 cell => (if (!trace orelse !stats) 
42012
2c3fe3cbebae
structure Timing: covers former start_timing/end_timing and Output.timeit etc;
wenzelm
parents:
41491
diff
changeset

1265 
then writeln (Timing.message (Timing.result start) ^ " for reconstruction") 
18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1266 
else (); 
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1267 
Seq.make(fn()=> cell)) 
4323
561242f8606b
Printing of statistics including time for search & reconstruction
paulson
parents:
4300
diff
changeset

1268 
end 
42369  1269 
in 
42801
da4ad5f98953
proper Proof.context  eliminated global operations;
wenzelm
parents:
42793
diff
changeset

1270 
prove (state, start, [initBranch (mkGoal concl :: hyps, lim)], cont) 
42369  1271 
> Seq.map (rotate_prems (1  i)) 
1272 
end 

1273 
handle PROVE => Seq.empty; 

2854  1274 

4391
cc3e8453d7f0
More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents:
4354
diff
changeset

1275 
(*Public version with fixed depth*) 
42793  1276 
fun depth_tac ctxt lim i st = timing_depth_tac (Timing.start ()) ctxt lim i st; 
4391
cc3e8453d7f0
More deterministic and therefore faster (sometimes) proof reconstruction
paulson
parents:
4354
diff
changeset

1277 

42616
92715b528e78
added Attrib.setup_config_XXX conveniences, with implicit setup of the background theory;
wenzelm
parents:
42477
diff
changeset

1278 
val (depth_limit, setup_depth_limit) = 
42801
da4ad5f98953
proper Proof.context  eliminated global operations;
wenzelm
parents:
42793
diff
changeset

1279 
Attrib.config_int @{binding blast_depth_limit} (K 20); 
15162
670ab8497818
depth limit (previously hardcoded with a value of 20) made a reference
webertj
parents:
14984
diff
changeset

1280 

42793  1281 
fun blast_tac ctxt i st = 
42801
da4ad5f98953
proper Proof.context  eliminated global operations;
wenzelm
parents:
42793
diff
changeset

1282 
((DEEPEN (1, Config.get ctxt depth_limit) (timing_depth_tac (Timing.start ()) ctxt) 0) i 
da4ad5f98953
proper Proof.context  eliminated global operations;
wenzelm
parents:
42793
diff
changeset

1283 
THEN flexflex_tac) st 
da4ad5f98953
proper Proof.context  eliminated global operations;
wenzelm
parents:
42793
diff
changeset

1284 
handle TRANS s => (if !trace then warning ("blast: " ^ s) else (); Seq.empty); 
2854  1285 

1286 

2924
af506c35b4ed
Control over excessive branching by applying a log2 penalty
paulson
parents:
2894
diff
changeset

1287 

18525
ce1ae48c320f
avoid implicit assumptions about consts Not, op =, *Goal*, *False*;
wenzelm
parents:
18177
diff
changeset

1288 
(*** For debugging: these apply the prover to a subgoal and return 
2924
af506c35b4ed
Control over excessive branching by applying a log2 penalty
paulson
parents:
2894
diff
changeset

1289 
the resulting tactics, trace, etc. ***) 
af506c35b4ed
Control over excessive branching by applying a log2 penalty
paulson
parents:
2894
diff
changeset

1290 

32740  1291 
val fullTrace = Unsynchronized.ref ([]: branch list list); 
2924 