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 print s = prerr_endline (Lazy.force s) ;;
26 (t Terms.bag * int * t Terms.substitution * int list) list
29 | Timeout of int * t Terms.bag
30 type bag = t Terms.bag * int
32 val empty_state : state
33 val bag_of_state : state -> bag
34 val replace_bag: state -> bag -> state
35 val mk_passive : bag -> input * input -> bag * t Terms.unit_clause
36 val mk_goal : bag -> input * input -> bag * t Terms.unit_clause
37 val forward_infer_step :
39 t Terms.unit_clause ->
53 g_passives:t Terms.unit_clause list ->
54 passives:t Terms.unit_clause list -> szsontology
56 state -> input* input -> szsontology
58 state -> input* input -> szsontology
63 state -> input* input -> szsontology
66 module Paramod (B : Orderings.Blob) = struct
68 module FU = FoUnif.Founif(B)
69 module IDX = Index.Index(B)
70 module Sup = Superposition.Superposition(B)
71 module Utils = FoUtils.Utils(B)
73 module WeightOrderedPassives =
75 type t = B.t Terms.passive_clause
76 let compare = Utils.compare_passive_clauses_weight
79 module AgeOrderedPassives =
81 type t = B.t Terms.passive_clause
82 let compare = Utils.compare_passive_clauses_age
85 module WeightPassiveSet = Set.Make(WeightOrderedPassives)
86 module AgePassiveSet = Set.Make(AgeOrderedPassives)
90 type bag = B.t Terms.bag * int
93 (B.t Terms.bag * int * B.t Terms.substitution * int list) list
96 | Timeout of int * B.t Terms.bag
97 exception Stop of szsontology
101 * Index.Index(B).active_set
102 * (IDX.DT.t * WeightPassiveSet.t * AgePassiveSet.t)
103 * B.t Terms.unit_clause list
104 * (WeightPassiveSet.t * AgePassiveSet.t)
110 (IDX.DT.empty,WeightPassiveSet.empty,AgePassiveSet.empty),
112 (WeightPassiveSet.empty,AgePassiveSet.empty)
115 let bag_of_state (bag,n,_,_,_,_) = bag,n
118 let replace_bag (_,_,a,b,c,d) (bag,n) = bag,n,a,b,c,d
121 let add_passive_clause ?(no_weight=false)
122 (passive_t,passives_w,passives_a) cl =
123 let pcl = if no_weight then (0,cl)
124 else Utils.mk_passive_clause cl in
125 IDX.index_unit_clause passive_t cl,
126 WeightPassiveSet.add pcl passives_w,
127 AgePassiveSet.add pcl passives_a
130 let add_passive_goal ?(no_weight=false) (passives_w,passives_a) g =
131 let g = if no_weight then (0,g)
132 else Utils.mk_passive_goal g in
133 WeightPassiveSet.add g passives_w, AgePassiveSet.add g passives_a
136 let remove_passive_clause (passive_t,passives_w,passives_a) cl =
137 let passive_t = IDX.remove_unit_clause passive_t (snd cl) in
138 let passives_w = WeightPassiveSet.remove cl passives_w in
139 let passives_a = AgePassiveSet.remove cl passives_a in
140 passive_t,passives_w,passives_a
143 let add_passive_clauses ?(no_weight=false) =
144 List.fold_left (add_passive_clause ~no_weight)
147 let add_passive_goals ?(no_weight=false)
148 (passives_w,passives_a) new_clauses =
149 let new_clauses_w,new_clauses_a =
150 List.fold_left (add_passive_goal ~no_weight)
151 (WeightPassiveSet.empty,AgePassiveSet.empty) new_clauses
153 (WeightPassiveSet.union new_clauses_w passives_w,
154 AgePassiveSet.union new_clauses_a passives_a)
157 let remove_passive_goal (passives_w,passives_a) cl =
158 let passives_w = WeightPassiveSet.remove cl passives_w in
159 let passives_a = AgePassiveSet.remove cl passives_a in
160 passives_w,passives_a
163 let is_passive_set_empty (_,passives_w,passives_a) =
164 if (WeightPassiveSet.is_empty passives_w) then begin
165 assert (AgePassiveSet.is_empty passives_a); true
167 assert (not (AgePassiveSet.is_empty passives_a)); false
171 let is_passive_g_set_empty (passives_w,passives_a) =
172 if (WeightPassiveSet.is_empty passives_w) then begin
173 assert (AgePassiveSet.is_empty passives_a); true
175 assert (not (AgePassiveSet.is_empty passives_a)); false
179 let passive_set_cardinal (_,passives_w,_)
180 = WeightPassiveSet.cardinal passives_w
183 let g_passive_set_cardinal (passives_w,_)
184 = WeightPassiveSet.cardinal passives_w
187 let passive_empty_set =
188 (IDX.DT.empty,WeightPassiveSet.empty,AgePassiveSet.empty)
191 let g_passive_empty_set =
192 (WeightPassiveSet.empty,AgePassiveSet.empty)
195 let pick_min_passive ~use_age (_,passives_w,passives_a) =
196 if use_age then AgePassiveSet.min_elt passives_a
197 else WeightPassiveSet.min_elt passives_w
200 let pick_min_g_passive ~use_age (passives_w,passives_a) =
201 if use_age then AgePassiveSet.min_elt passives_a
202 else WeightPassiveSet.min_elt passives_w
205 let mk_unit_clause bag maxvar (t,ty) =
206 let c, maxvar = Utils.mk_unit_clause maxvar (B.embed ty) (B.embed t) in
207 let bag, c = Terms.add_to_bag c bag in
212 let mk_clause bag maxvar (proof,ty) =
213 let (proof,ty) = B.saturate t ty in
214 let c, maxvar = Utils.mk_unit_clause maxvar ty proof in
215 let bag, c = Terms.add_to_bag c bag in
219 let mk_passive (bag,maxvar) = mk_unit_clause bag maxvar;;
221 let mk_goal (bag,maxvar) = mk_unit_clause bag maxvar;;
223 let initialize_goal (bag,maxvar,actives,passives,_,_) t =
224 let (bag,maxvar), g = mk_unit_clause bag maxvar t in
225 let g_passives = g_passive_empty_set in
226 (* if the goal is not an equation we returns an empty
229 if Terms.is_eq_clause g then add_passive_goal g_passives g
232 (bag,maxvar,actives,passives,[],g_passives)
235 (* TODO : global age over facts and goals (without comparing weights) *)
236 let select ~use_age passives g_passives =
237 if is_passive_set_empty passives then begin
238 if (is_passive_g_set_empty g_passives) then
239 raise (Stop GaveUp) (* we say we are incomplete *)
241 let g_cl = pick_min_g_passive ~use_age:use_age g_passives in
242 (true,g_cl,passives,remove_passive_goal g_passives g_cl)
244 else let cl = pick_min_passive ~use_age:use_age passives in
245 if is_passive_g_set_empty g_passives then
246 (false,cl,remove_passive_clause passives cl,g_passives)
248 let g_cl = pick_min_g_passive ~use_age:use_age g_passives in
249 let (id1,_,_,_),(id2,_,_,_) = snd cl, snd g_cl in
250 let cmp = if use_age then id1 <= id2
251 else fst cl <= fst g_cl
254 (false,cl,remove_passive_clause passives cl,g_passives)
256 (true,g_cl,passives,remove_passive_goal g_passives g_cl)
259 let backward_infer_step bag maxvar actives passives
260 g_actives g_passives g_current iterno =
261 (* superposition left, simplifications on goals *)
262 debug (lazy "infer_left step...");
263 let bag, maxvar, new_goals =
264 Sup.infer_left bag maxvar g_current actives
266 debug (lazy "Performed infer_left step");
267 let bag = Terms.replace_in_bag (g_current,false,iterno) bag in
268 bag, maxvar, actives, passives, g_current::g_actives,
269 (add_passive_goals g_passives new_goals)
272 let pp_clauses actives passives =
273 let actives_l, _ = actives in
274 let passive_t,_,_ = passives in
275 let wset = IDX.elems passive_t in
276 ("Actives :" ^ (String.concat ";\n"
277 (List.map Pp.pp_unit_clause actives_l)))
279 ("Passives:" ^(String.concat ";\n"
280 (List.map (fun (_,cl) -> Pp.pp_unit_clause cl)
281 (IDX.ClauseSet.elements wset))))
284 let forward_infer_step
285 ((bag,maxvar,actives,passives,g_actives,g_passives) as s)
291 * A' = demod [e'] A *
294 * new = supright e'' A'' *
295 * new'= demod A'' new *
297 debug (lazy "Forward infer step...");
298 debug (lazy("Number of actives : " ^ (string_of_int (List.length (fst actives)))));
299 noprint (lazy (pp_clauses actives passives));
300 match Sup.keep_simplified current actives bag maxvar
303 | bag,Some (current,actives) ->
304 debug (lazy ("simplified to " ^ (Pp.pp_unit_clause current)));
305 let bag, maxvar, actives, new_clauses =
306 Sup.infer_right bag maxvar current actives
310 ("New clauses :" ^ (String.concat ";\n"
311 (List.map Pp.pp_unit_clause new_clauses))));
312 debug (lazy "Demodulating goals with actives...");
313 (* keep goals demodulated w.r.t. actives and check if solved *)
318 Sup.simplify_goal ~no_demod:false maxvar (snd actives) bag acc c
321 | Some (bag,c1) -> bag,if c==c1 then c::acc else c::c1::acc)
324 let ctable = IDX.index_unit_clause IDX.DT.empty current in
325 let bag, maxvar, new_goals =
327 (fun (bag,m,acc) g ->
328 let bag, m, ng = Sup.infer_left bag m g ([current],ctable) in
330 (bag,maxvar,[]) g_actives
332 let bag = Terms.replace_in_bag (current,false,iterno) bag in
333 (* prerr_endline (Pp.pp_bag bag); *)
334 bag, maxvar, actives,
335 add_passive_clauses passives new_clauses, g_actives,
336 add_passive_goals g_passives new_goals
339 let debug_status (_,_,actives,passives,g_actives,g_passives) =
341 ((Printf.sprintf "Number of active goals : %d\n"
342 (List.length g_actives)) ^
343 (Printf.sprintf "Number of passive goals : %d\n"
344 (g_passive_set_cardinal g_passives)) ^
345 (Printf.sprintf "Number of actives : %d\n"
346 (List.length (fst actives))) ^
347 (Printf.sprintf "Number of passives : %d\n"
348 (passive_set_cardinal passives)))
352 (* we just check if any of the active goals is subsumed by a
353 passive clause, or if any of the passive goal is subsumed
354 by an active or passive clause *)
355 let last_chance (bag,maxvar,actives,passives,g_actives,g_passives) =
356 debug (lazy("Last chance " ^ string_of_float
357 (Unix.gettimeofday())));
358 let actives_l, active_t = actives in
359 let passive_t,wset,_ = passives in
362 ("Actives :" ^ (String.concat ";\n"
363 (List.map Pp.pp_unit_clause actives_l)))) in
364 let wset = IDX.elems passive_t in
367 ("Passives:" ^(String.concat ";\n"
368 (List.map (fun (_,cl) -> Pp.pp_unit_clause cl)
369 (IDX.ClauseSet.elements wset))))) in
371 WeightPassiveSet.fold
373 if List.exists (Sup.are_alpha_eq x) g_actives then acc
381 (debug (lazy("ckecking goal vs a: " ^ Pp.pp_unit_clause x));
382 Sup.simplify_goal ~no_demod:true maxvar active_t bag [] x))
388 (debug (lazy("ckecking goal vs p: " ^ Pp.pp_unit_clause x));
389 Sup.simplify_goal ~no_demod:true maxvar passive_t bag [] x))
390 (g_actives@g_passives));
391 raise (Stop (Timeout (maxvar,bag)))
393 let check_timeout = function
395 | Some timeout -> Unix.gettimeofday () > timeout
397 let rec given_clause ~useage
398 bag maxvar iterno weight_picks max_steps timeout
399 actives passives g_actives g_passives
401 let iterno = iterno + 1 in
402 if iterno = max_steps || check_timeout timeout then
403 last_chance (bag,maxvar,actives,passives,g_actives,g_passives)
405 let use_age = useage && (weight_picks = (iterno / 6 + 1)) in
406 let weight_picks = if use_age then 0 else weight_picks+1
409 let rec aux_select bag
410 (passives:IDX.DT.t * WeightPassiveSet.t * AgePassiveSet.t)
412 let backward,(weight,current),passives,g_passives =
413 select ~use_age passives g_passives
415 if use_age && weight > monster then
416 let bag,cl = Terms.add_to_bag current bag in
418 aux_select bag passives (add_passive_goal g_passives cl)
420 aux_select bag (add_passive_clause passives cl) g_passives
422 let bag = Terms.replace_in_bag (current,false,iterno) bag in
424 let _ = debug (lazy("Selected goal : " ^ Pp.pp_unit_clause current)) in
427 ~no_demod:false maxvar (snd actives) bag g_actives current
429 | None -> aux_select bag passives g_passives
430 | Some (bag,g_current) ->
431 backward_infer_step bag maxvar actives passives
432 g_actives g_passives g_current iterno
434 let _ = debug (lazy("Selected fact : " ^ Pp.pp_unit_clause current))
436 if Sup.orphan_murder bag (fst actives) current then
437 let _ = debug (lazy "Orphan murdered") in
438 let bag = Terms.replace_in_bag (current,true,iterno) bag in
439 aux_select bag passives g_passives
441 let s = bag,maxvar,actives,passives,g_actives,g_passives in
442 let s1 = forward_infer_step s current iterno
444 if s == s1 then aux_select bag passives g_passives
447 (*prerr_endline "Active table :";
448 (List.iter (fun x -> prerr_endline (Pp.pp_unit_clause x))
451 let (bag,maxvar,actives,passives,g_actives,g_passives) as status =
452 aux_select bag passives g_passives
454 debug (debug_status status);
456 bag maxvar iterno weight_picks max_steps timeout
457 actives passives g_actives g_passives
460 let check_and_infer ~no_demod iterno status current =
461 let bag,maxvar,actives,passives,g_actives,g_passives = status in
464 ~no_demod maxvar (snd actives) bag g_actives current
466 | None -> debug (lazy "None"); status
467 | Some (bag,g_current) ->
469 debug (lazy("Infer on goal : "
470 ^ Pp.pp_unit_clause g_current))
472 backward_infer_step bag maxvar actives passives
473 g_actives g_passives g_current iterno
475 (* similar to given_clause, but it merely works on goals,
476 in parallel, at each iteration *)
477 let rec goal_narrowing iterno max_steps timeout status
479 debug (debug_status status);
480 let iterno = iterno + 1 in
481 if iterno = max_steps || check_timeout timeout then
484 let _,_,_,_,_,g_passives = status in
485 let passive_goals = WeightPassiveSet.elements (fst g_passives) in
489 let bag,maxvar,actives,passives,g_actives,g_passives = acc in
491 remove_passive_goal g_passives g in
492 let current = snd g in
494 debug (lazy("Selected goal : " ^ Pp.pp_unit_clause current))
496 (* we work both on the original goal and the demodulated one*)
497 let acc = check_and_infer ~no_demod:false iterno acc current
498 in check_and_infer ~no_demod:true iterno acc current)
501 goal_narrowing iterno max_steps timeout newstatus
503 let compute_result bag i subst =
505 let rec traverse ongoal (accg,acce) i =
506 match Terms.get_from_bag i bag with
507 | (id,_,_,Terms.Exact _),_,_ ->
508 if ongoal then [i],acce else
509 if (List.mem i acce) then accg,acce else accg,acce@[i]
510 | (_,_,_,Terms.Step (_,i1,i2,_,_,_)),_,_ ->
511 if (not ongoal) && (List.mem i acce) then accg,acce
514 traverse false (traverse ongoal (accg,acce) i1) i2
516 if ongoal then i::accg,acce else accg,i::acce
518 let gsteps,esteps = traverse true ([],[]) i in
519 (List.rev esteps)@gsteps
521 debug (lazy ("steps: " ^ (string_of_int (List.length l))));
525 let (cl,_,_) = Terms.get_from_bag i bag in
526 max acc (Order.compute_unit_clause_weight cl)) 0 l in
527 debug (lazy ("Max weight : " ^ (string_of_int max_w)));
528 (* List.iter (fun id -> let ((_,lit,_,proof as cl),d,it) =
529 Terms.get_from_bag id bag in
532 (Printf.sprintf "Id : %d, selected at %d, weight %d,disc, by %s"
533 id it (Order.compute_unit_clause_weight cl)
534 (Pp.pp_proof_step proof))
537 (Printf.sprintf "Id : %d, selected at %d, weight %d by %s"
538 id it (Order.compute_unit_clause_weight cl)
539 (Pp.pp_proof_step proof))) l;*)
540 debug (lazy ("Proof:" ^
544 let cl,_,_ = Terms.get_from_bag x bag in
545 Pp.pp_unit_clause cl) l))));
546 Unsatisfiable [ bag, i, subst, l ]
548 let paramod ~useage ~max_steps ?timeout (bag,maxvar) ~g_passives ~passives =
549 let _initial_timestamp = Unix.gettimeofday () in
551 add_passive_clauses ~no_weight:true passive_empty_set passives
554 add_passive_goals ~no_weight:true g_passive_empty_set g_passives
556 let g_actives = [] in
557 let actives = [], IDX.DT.empty in
559 given_clause ~useage ~noinfer:false
560 bag maxvar 0 0 max_steps timeout actives passives g_actives g_passives
562 | Sup.Success (bag, _, (i,_,_,_),subst) ->
563 compute_result bag i subst
564 | Stop (Unsatisfiable _) -> Error "solution found!"
569 let bag,maxvar,actives,passives,g_actives,g_passives = s in
570 let (bag,maxvar), g = mk_goal (bag,maxvar) goal in
571 let bag, ((i,_,_,_) as g1) = Sup.demodulate bag g (snd actives) in
572 if g1 = g then GaveUp else compute_result bag i []
574 if Terms.is_eq_clause g then
578 let fast_eq_check s goal =
579 let (_,_,_,_,_,g_passives) as s = initialize_goal s goal in
580 if is_passive_g_set_empty g_passives then Error "not an equation"
583 goal_narrowing 0 2 None s
585 | Sup.Success (bag, _, (i,_,_,_),subst) ->
586 compute_result bag i subst
587 | Stop (Unsatisfiable _) -> Error "solution found!"
591 let nparamod ~useage ~max_steps ?timeout s goal =
592 let bag,maxvar,actives,passives,g_actives,g_passives
593 = initialize_goal s goal in
594 if is_passive_g_set_empty g_passives then Error "not an equation"
596 try given_clause ~useage ~noinfer:false
597 bag maxvar 0 0 max_steps timeout actives passives g_actives g_passives
599 | Sup.Success (bag, _, (i,_,_,_),subst) ->
600 compute_result bag i subst
601 | Stop (Unsatisfiable _) -> Error "solution found!"