--- a/src/Provers/astar.ML Thu Mar 14 12:21:07 1996 +0100
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,59 +0,0 @@
-(* Title: astar
- ID: $Id$
- Author: Norbert Voelker, FernUniversitaet Hagen
- Remarks: Implementation of A*-like proof procedure by modification
- of the existing code for BEST_FIRST and best_tac so that the
- current level of search is taken into account.
-*)
-
-(*Insertion into priority queue of states, marked with level *)
-fun insert_with_level (lnth: int*int*thm, []) = [lnth]
- | insert_with_level ((l,m,th), (l',n,th')::nths) =
- if n<m then (l',n,th') :: insert_with_level ((l,m,th), nths)
- else if n=m andalso eq_thm(th,th')
- then (l',n,th')::nths
- else (l,m,th)::(l',n,th')::nths;
-
-(*For creating output sequence*)
-fun some_of_list [] = None
- | some_of_list (x::l) = Some (x, Sequence.seqof (fn () => some_of_list l));
-
-infix THEN_ASTAR;
-val trace_ASTAR = ref false;
-
-fun tf0 THEN_ASTAR (satp, costf, tac) =
- let val tf = tracify trace_ASTAR tac;
- fun bfs (news,nprfs,level) =
- let fun cost thm = (level,costf level thm,thm)
- in (case partition satp news of
- ([],nonsats)
- => next (foldr insert_with_level (map cost nonsats, nprfs))
- | (sats,_) => some_of_list sats)
- end and
- next [] = None
- | next ((level,n,prf)::nprfs) =
- (if !trace_ASTAR
- then writeln("level = " ^ string_of_int level ^
- " cost = " ^ string_of_int n ^
- " queue length =" ^ string_of_int (length nprfs))
- else ();
- bfs (Sequence.list_of_s (tf prf), nprfs,level+1))
- fun tf st = bfs (Sequence.list_of_s (tf0 st), [], 0)
- in traced_tac tf end;
-
-(*Ordinary ASTAR, with no initial tactic*)
-fun ASTAR (satp,costf) tac = all_tac THEN_ASTAR (satp,costf,tac);
-
-(* ASTAR with weight weight_ASTAR as a classical prover *)
-val weight_ASTAR = ref 5;
-
-fun astar_tac cs =
- SELECT_GOAL ( ASTAR (has_fewer_prems 1
- , fn level =>(fn thm =>size_of_thm thm + !weight_ASTAR *level))
- (step_tac cs 1));
-
-fun slow_astar_tac cs =
- SELECT_GOAL ( ASTAR (has_fewer_prems 1
- , fn level =>(fn thm =>size_of_thm thm + !weight_ASTAR *level))
- (slow_step_tac cs 1));
-