2 ||M|| This file is part of HELM, an Hypertextual, Electronic
3 ||A|| Library of Mathematics, developed at the Computer Science
4 ||T|| Department, University of Bologna, Italy.
6 ||T|| HELM is free software; you can redistribute it and/or
7 ||A|| modify it under the terms of the GNU General Public License
8 \ / version 2 or (at your option) any later version.
9 \ / This software is distributed as is, NO WARRANTY.
10 V_______________________________________________________________ *)
12 (* $Id: orderings.ml 9869 2009-06-11 22:52:38Z denes $ *)
14 let debug s = prerr_endline s ;;
17 module Paramod (B : Terms.Blob) = struct
18 exception Failure of string * B.t Terms.bag * int * int
19 type bag = B.t Terms.bag * int
21 module FU = FoUnif.Founif(B)
22 module IDX = Index.Index(B)
23 module Sup = Superposition.Superposition(B)
24 module Utils = FoUtils.Utils(B)
25 module WeightOrderedPassives =
27 type t = B.t Terms.passive_clause
28 let compare = Utils.compare_passive_clauses_weight
31 module AgeOrderedPassives =
33 type t = B.t Terms.passive_clause
34 let compare = Utils.compare_passive_clauses_age
37 module WeightPassiveSet = Set.Make(WeightOrderedPassives)
38 module AgePassiveSet = Set.Make(AgeOrderedPassives)
40 let add_passive_clause ?(no_weight=false) (passives_w,passives_a) cl =
41 let cl = if no_weight then (0,cl)
42 else Utils.mk_passive_clause cl in
43 WeightPassiveSet.add cl passives_w, AgePassiveSet.add cl passives_a
46 let remove_passive_clause (passives_w,passives_a) cl =
47 let passives_w = WeightPassiveSet.remove cl passives_w in
48 let passives_a = AgePassiveSet.remove cl passives_a in
52 let add_passive_clauses (passives_w,passives_a) new_clauses =
53 let new_clauses_w,new_clauses_a = List.fold_left add_passive_clause
54 (WeightPassiveSet.empty,AgePassiveSet.empty) new_clauses
56 (WeightPassiveSet.union new_clauses_w passives_w,
57 AgePassiveSet.union new_clauses_a passives_a)
60 let is_passive_set_empty (passives_w,passives_a) =
61 if (WeightPassiveSet.is_empty passives_w) then begin
62 assert (AgePassiveSet.is_empty passives_a); true
64 assert (not (AgePassiveSet.is_empty passives_a)); false
68 let passive_set_cardinal (passives_w,_) = WeightPassiveSet.cardinal passives_w
70 let passive_empty_set =
71 (WeightPassiveSet.empty,AgePassiveSet.empty)
74 let pick_min_passive ~use_age (passives_w,passives_a) =
75 if use_age then AgePassiveSet.min_elt passives_a
76 else WeightPassiveSet.min_elt passives_w
79 let mk_clause bag maxvar (t,ty) =
80 let (proof,ty) = B.saturate t ty in
81 let c, maxvar = Utils.mk_unit_clause maxvar ty proof in
82 let bag, c = Utils.add_to_bag bag c in
86 let mk_passive (bag,maxvar) = mk_clause bag maxvar;;
87 let mk_goal (bag,maxvar) = mk_clause bag maxvar;;
89 (* TODO : global age over facts and goals (without comparing weights) *)
90 let select ~use_age passives g_passives =
91 if is_passive_set_empty passives then begin
92 assert (not (is_passive_set_empty g_passives));
93 let g_cl = pick_min_passive ~use_age:use_age g_passives in
94 (true,snd g_cl,passives,remove_passive_clause g_passives g_cl)
96 else let cl = pick_min_passive ~use_age:use_age passives in
97 if is_passive_set_empty g_passives then
98 (false,snd cl,remove_passive_clause passives cl,g_passives)
100 let g_cl = pick_min_passive ~use_age:use_age g_passives in
101 if (fst cl <= fst g_cl) then
102 (false,snd cl,remove_passive_clause passives cl,g_passives)
104 (true,snd g_cl,passives,remove_passive_clause g_passives g_cl)
107 let backward_infer_step bag maxvar actives passives
108 g_actives g_passives g_current =
109 (* superposition left, simplifications on goals *)
110 debug "infer_left step...";
111 let bag, maxvar, new_goals =
112 Sup.infer_left bag maxvar g_current actives
114 debug "Performed infer_left step";
115 bag, maxvar, actives, passives, g_current::g_actives,
116 (add_passive_clauses g_passives new_goals)
119 let forward_infer_step bag maxvar actives passives g_actives
125 * A' = demod [e'] A *
128 * new = supright e'' A'' *
129 * new'= demod A'' new *
131 debug "Forward infer step...";
132 let bag, maxvar, actives, new_clauses =
133 Sup.infer_right bag maxvar current actives
135 debug "Demodulating goals with actives...";
136 (* keep goals demodulated w.r.t. actives and check if solved *)
140 match Sup.simplify_goal maxvar (snd actives) bag acc c with
142 | Some (bag,c) -> bag,c::acc)
145 let ctable = IDX.index_unit_clause IDX.DT.empty current in
146 let bag, maxvar, new_goals =
148 (fun (bag,m,acc) g ->
149 let bag, m, ng = Sup.infer_left bag m g
150 ([current],ctable) in
152 (bag,maxvar,[]) g_actives
154 bag, maxvar, actives,
155 add_passive_clauses passives new_clauses, g_actives,
156 add_passive_clauses g_passives new_goals
160 bag maxvar iterno max_steps timeout
161 actives passives g_actives g_passives
163 let iterno = iterno + 1 in
164 if iterno = max_steps then
165 raise (Failure ("No iterations left !",bag,maxvar,iterno));
166 (* timeout check: gettimeofday called only if timeout set *)
170 if Unix.gettimeofday () > timeout then
171 raise (Failure ("Timeout !",bag,maxvar,iterno)));
173 let use_age = iterno mod 10 = 0 in
175 let rec aux_select passives g_passives =
176 let backward,current,passives,g_passives =
177 select ~use_age:false passives g_passives
180 match Sup.simplify_goal maxvar (snd actives) bag g_actives current with
181 | None -> aux_select passives g_passives
182 | Some x -> let bag,g_current = x in
183 backward_infer_step bag maxvar actives passives
184 g_actives g_passives g_current
186 (* debug ("Selected fact : " ^ Pp.pp_unit_clause current); *)
187 match Sup.keep_simplified current actives bag maxvar with
188 (* match Sup.one_pass_simplification current actives bag maxvar with*)
189 | None -> aux_select passives g_passives
190 | Some x -> let (current, bag, actives) = x in
191 forward_infer_step bag maxvar actives passives
192 g_actives g_passives current
195 (* prerr_endline "Bag :"; prerr_endline (Pp.pp_bag bag);
196 prerr_endline "Active table :";
197 (List.iter (fun x -> prerr_endline (Pp.pp_unit_clause x))
200 let bag,maxvar,actives,passives,g_actives,g_passives =
201 aux_select passives g_passives
204 (Printf.sprintf "Number of active goals : %d"
205 (List.length g_actives));
207 (Printf.sprintf "Number of passive goals : %d"
208 (passive_set_cardinal g_passives));
210 (Printf.sprintf "Number of actives : %d" (List.length (fst actives)));
212 (Printf.sprintf "Number of passives : %d"
213 (passive_set_cardinal passives));
215 bag maxvar iterno max_steps timeout
216 actives passives g_actives g_passives
219 let paramod ~max_steps ?timeout (bag,maxvar) ~g_passives ~passives =
220 let initial_timestamp = Unix.gettimeofday () in
221 let passives = add_passive_clauses passive_empty_set passives in
222 let g_passives = add_passive_clauses passive_empty_set g_passives in
223 let g_actives = [] in
224 let actives = [], IDX.DT.empty in
227 bag maxvar 0 max_steps timeout actives passives g_actives g_passives
229 | Sup.Success (bag, _, (i,_,_,_)) ->
231 let rec traverse ongoal (accg,acce) i =
232 match Terms.M.find i bag with
233 | (id,_,_,Terms.Exact _),_ ->
234 if ongoal then [i],acce else
235 if (List.mem i acce) then accg,acce else accg,acce@[i]
236 | (_,_,_,Terms.Step (_,i1,i2,_,_,_)),_ ->
237 if (not ongoal) && (List.mem i acce) then accg,acce
240 traverse false (traverse ongoal (accg,acce) i1) i2
242 if ongoal then i::accg,acce else accg,i::acce
244 let gsteps,esteps = traverse true ([],[]) i in
245 (List.rev esteps)@gsteps
248 (Printf.sprintf "Found proof, %fs"
249 (Unix.gettimeofday() -. initial_timestamp));
251 prerr_endline "Proof:";
253 prerr_endline (Pp.pp_unit_clause (fst(Terms.M.find x bag)))) l;
256 | Failure (msg,_bag,_maxvar,iterno) ->
258 prerr_endline (Printf.sprintf "FAILURE in %d iterations" iterno);