(* $Id: index.mli 9822 2009-06-03 15:37:06Z tassi $ *)
-module Superposition (B : Terms.Blob) =
+module Superposition (B : Orderings.Blob) =
struct
module IDX = Index.Index(B)
module Unif = FoUnif.Founif(B)
module Subst = FoSubst
- module Order = Orderings.Orderings(B)
+ module Order = B
module Utils = FoUtils.Utils(B)
module Pp = Pp.Pp(B)
- exception Success of B.t Terms.bag * int * B.t Terms.unit_clause
-
- let debug s = prerr_endline s;;
- let debug _ = ();;
+ exception Success of
+ B.t Terms.bag
+ * int
+ * B.t Terms.unit_clause
+ * B.t Terms.substitution
+
+ (* let debug s = prerr_endline (Lazy.force s);; *)
+ let debug _ = ();;
let enable = true;;
let rec list_first f = function
let rec aux bag pos ctx id = function
| Terms.Leaf _ as t -> f bag t pos ctx id
| Terms.Var _ as t -> bag,t,id
- | Terms.Node l as t->
+ | Terms.Node (hd::l) as t->
let bag,t,id1 = f bag t pos ctx id in
if id = id1 then
let bag, l, _, id =
let bag,newt,id = aux bag newpos newctx id t in
if post = [] then bag, pre@[newt], [], id
else bag, pre @ [newt], List.tl post, id)
- (bag, [], List.tl l, id) l
+ (bag, [hd], List.tl l, id) l
in
bag, Terms.Node l, id
- else bag,t,id1
+ else bag,t,id1
+ (* else aux bag pos ctx id1 t *)
+ | _ -> assert false
in
aux bag pos ctx id t
;;
+
+ let visit bag pos ctx id t f =
+ let rec aux bag pos ctx id subst = function
+ | Terms.Leaf _ as t ->
+ let bag,subst,t,id = f bag t pos ctx id
+ in assert (subst=[]); bag,t,id
+ | Terms.Var i as t ->
+ let t= Subst.apply_subst subst t in
+ bag,t,id
+ | Terms.Node (hd::l) ->
+ let bag, l, _, id =
+ List.fold_left
+ (fun (bag,pre,post,id) t ->
+ let newctx = fun x -> ctx (Terms.Node (pre@[x]@post)) in
+ let newpos = (List.length pre)::pos in
+ let bag,newt,id = aux bag newpos newctx id subst t in
+ if post = [] then bag, pre@[newt], [], id
+ else bag, pre @ [newt], List.tl post, id)
+ (bag, [hd], List.map (Subst.apply_subst subst) (List.tl l), id) l
+ in
+ let bag,subst,t,id1 = f bag (Terms.Node l) pos ctx id
+ in
+ if id1 = id then (assert (subst=[]); bag,t,id)
+ else aux bag pos ctx id1 subst t
+ | _ -> assert false
+ in
+ aux bag pos ctx id [] t
+ ;;
let build_clause bag filter rule t subst id id2 pos dir =
let proof = Terms.Step(rule,id,id2,dir,pos,subst) in
let t = Subst.apply_subst subst t in
- if filter t then
+ if filter subst then
let literal =
match t with
| Terms.Node [ Terms.Leaf eq ; ty; l; r ] when B.eq B.eqP eq ->
let prof_demod_u = HExtlib.profile ~enable "demod.unify";;
let prof_demod_r = HExtlib.profile ~enable "demod.retrieve_generalizations";;
let prof_demod_o = HExtlib.profile ~enable "demod.compare_terms";;
+ let prof_demod_s = HExtlib.profile ~enable "demod.apply_subst";;
let demod table varlist subterm =
let cands =
try
let subst =
prof_demod_u.HExtlib.profile
- (Unif.unification (varlist@vl) varlist subterm) side
+ (Unif.unification (* (varlist@vl) *) varlist subterm) side
in
- let side = Subst.apply_subst subst side in
- let newside = Subst.apply_subst subst newside in
- if o = Terms.Incomparable then
+ let side =
+ prof_demod_s.HExtlib.profile
+ (Subst.apply_subst subst) side
+ in
+ let newside =
+ prof_demod_s.HExtlib.profile
+ (Subst.apply_subst subst) newside
+ in
+ if o = Terms.Incomparable || o = Terms.Invertible then
let o =
prof_demod_o.HExtlib.profile
(Order.compare_terms newside) side in
prof_demod.HExtlib.profile (demod table varlist) x
;;
- let demodulate_once_old ~jump_to_right bag (id, literal, vl, pr) table =
- match literal with
+ let mydemod table varlist subterm =
+ let cands =
+ prof_demod_r.HExtlib.profile
+ (IDX.DT.retrieve_generalizations table) subterm
+ in
+ list_first
+ (fun (dir, ((id,lit,vl,_) as c)) ->
+ debug (lazy("candidate: "
+ ^ Pp.pp_unit_clause c));
+ match lit with
+ | Terms.Predicate _ -> assert false
+ | Terms.Equation (l,r,_,o) ->
+ let side, newside = if dir=Terms.Left2Right then l,r else r,l in
+ try
+ let subst =
+ prof_demod_u.HExtlib.profile
+ (Unif.unification (* (varlist@vl) *) varlist subterm) side
+ in
+ let iside =
+ prof_demod_s.HExtlib.profile
+ (Subst.apply_subst subst) side
+ in
+ let inewside =
+ prof_demod_s.HExtlib.profile
+ (Subst.apply_subst subst) newside
+ in
+ if o = Terms.Incomparable || o = Terms.Invertible then
+ let o =
+ prof_demod_o.HExtlib.profile
+ (Order.compare_terms inewside) iside in
+ (* Riazanov, pp. 45 (ii) *)
+ if o = Terms.Lt then
+ Some (newside, subst, id, dir)
+ else
+ ((*prerr_endline ("Filtering: " ^
+ Pp.pp_foterm side ^ " =(< || =)" ^
+ Pp.pp_foterm newside ^ " coming from " ^
+ Pp.pp_unit_clause uc );*)None)
+ else
+ Some (newside, subst, id, dir)
+ with FoUnif.UnificationFailure _ -> None)
+ (IDX.ClauseSet.elements cands)
+ ;;
+
+ let ctx_demod table vl bag t pos ctx id =
+ match mydemod table vl t with
+ | None -> (bag,[],t,id)
+ | Some (newside, subst, id2, dir) ->
+ let inewside = Subst.apply_subst subst newside in
+ match build_clause bag (fun _ -> true)
+ Terms.Demodulation (ctx inewside) subst id id2 pos dir
+ with
+ | None -> assert false
+ | Some (bag,(id,_,_,_)) ->
+ (bag,subst,newside,id)
+ ;;
+
+ let rec demodulate bag (id, literal, vl, pr) table =
+ debug (lazy "demodulate...");
+ match literal with
| Terms.Predicate t -> assert false
| Terms.Equation (l,r,ty,_) ->
- let left_position = if jump_to_right then None else
- first_position [2]
- (fun x -> Terms.Node [ Terms.Leaf B.eqP; ty; x; r ]) l
- (demod table vl)
- in
- match left_position with
- | Some (newt, subst, id2, dir, pos) ->
- begin
- match build_clause bag (fun _ -> true) Terms.Demodulation
- newt subst id id2 pos dir
- with
- | None -> assert false
- | Some x -> Some (x,false)
- end
- | None ->
- match first_position
- [3] (fun x -> Terms.Node [ Terms.Leaf B.eqP; ty; l; x ]) r
- (demod table vl)
- with
- | None -> None
- | Some (newt, subst, id2, dir, pos) ->
- match build_clause bag (fun _ -> true)
- Terms.Demodulation newt subst id id2 pos dir
- with
- | None -> assert false
- | Some x -> Some (x,true)
+ let bag,l,id1 =
+ visit bag [2]
+ (fun x -> Terms.Node [ Terms.Leaf B.eqP; ty; x; r ]) id l
+ (ctx_demod table vl)
+ in
+ let bag,_,id2 =
+ visit bag [3]
+ (fun x -> Terms.Node [ Terms.Leaf B.eqP; ty; l; x ]) id1 r
+ (ctx_demod table vl)
+ in
+ let cl,_,_ = Terms.get_from_bag id2 bag in
+ bag,cl
;;
-
+
let parallel_demod table vl bag t pos ctx id =
match demod table vl t with
| None -> (bag,t,id)
(bag,newside,id)
;;
- let demodulate_once ~jump_to_right bag (id, literal, vl, pr) table =
- match literal with
- | Terms.Predicate t -> assert false
- | Terms.Equation (l,r,ty,_) ->
- let bag,l,id1 = if jump_to_right then (bag,l,id) else
- parallel_positions bag [2]
- (fun x -> Terms.Node [ Terms.Leaf B.eqP; ty; x; r ]) id l
- (parallel_demod table vl)
- in
- let jump_to_right = id1 = id in
- let bag,r,id2 =
- parallel_positions bag [3]
- (fun x -> Terms.Node [ Terms.Leaf B.eqP; ty; l; x ]) id1 r
- (parallel_demod table vl)
- in
- if id = id2 then None
- else
- let cl,_,_ = Terms.get_from_bag id2 bag in
- Some ((bag,cl),jump_to_right)
- ;;
-
- let rec demodulate ~jump_to_right bag clause table =
- match demodulate_once ~jump_to_right bag clause table with
- | None -> bag, clause
- | Some ((bag, clause),r) -> demodulate ~jump_to_right:r
- bag clause table
- ;;
-
- let rec demodulate_old ~jump_to_right bag clause table =
- match demodulate_once_old ~jump_to_right bag clause table with
- | None -> bag, clause
- | Some ((bag, clause),r) -> demodulate_old ~jump_to_right:r
- bag clause table
- ;;
-
let are_alpha_eq cl1 cl2 =
let get_term (_,lit,_,_) =
match lit with
with FoUnif.UnificationFailure _ -> false
;;
- let demodulate bag clause table =
-(* let (bag1,c1), (_,c2) =*)
- demodulate ~jump_to_right:false bag clause table
-(* demodulate_old ~jump_to_right:false bag clause table *)
-(* in
- if are_alpha_eq c1 c2 then bag1,c1
- else begin
- prerr_endline (Pp.pp_unit_clause c1);
- prerr_endline (Pp.pp_unit_clause c2);
- prerr_endline "Bag :";
- prerr_endline (Pp.pp_bag bag1);
- assert false
- end*)
- ;;
let prof_demodulate = HExtlib.profile ~enable "demodulate";;
let demodulate bag clause x =
prof_demodulate.HExtlib.profile (demodulate bag clause) x
;;
(* move away *)
- let is_identity_clause ~unify = function
+ let is_identity_clause = function
| _, Terms.Equation (_,_,_,Terms.Eq), _, _ -> true
- | _, Terms.Equation (l,r,_,_), vl, proof when unify ->
- (try ignore(Unif.unification vl [] l r); true
- with FoUnif.UnificationFailure _ -> false)
| _, Terms.Equation (_,_,_,_), _, _ -> false
| _, Terms.Predicate _, _, _ -> assert false
;;
+ let is_identity_goal = function
+ | _, Terms.Equation (_,_,_,Terms.Eq), _, _ -> Some []
+ | _, Terms.Equation (l,r,_,_), vl, proof ->
+ (try Some (Unif.unification (* vl *) [] l r)
+ with FoUnif.UnificationFailure _ -> None)
+ | _, Terms.Equation (_,_,_,_), _, _ -> None
+ | _, Terms.Predicate _, _, _ -> assert false
+ ;;
+
let build_new_clause bag maxvar filter rule t subst id id2 pos dir =
let maxvar, _vl, subst = Utils.relocate maxvar (Terms.vars_of_term
(Subst.apply_subst subst t)) subst in
in
bag, maxvar, res
;;
-
let rewrite_eq ~unify l r ty vl table =
let retrieve = if unify then IDX.DT.retrieve_unifiables
| [] -> None
| (id2,dir,c,vl1)::tl ->
try
- let subst = Unif.unification (vl@vl1) locked_vars c t in
+ let subst = Unif.unification (* (vl@vl1) *) locked_vars c t in
Some (id2, dir, subst)
with FoUnif.UnificationFailure _ -> aux tl
in
let l = Subst.apply_subst subst l in
let r = Subst.apply_subst subst r in
try
- let subst1 = Unif.unification vl [] l r in
+ let subst1 = Unif.unification (* vl *) [] l r in
let lit =
match lit with Terms.Predicate _ -> assert false
| Terms.Equation (l,r,ty,o) ->
let (id,_,_,_) = cl in
let actives = List.map (fun (i,_,_,_) -> i) actives in
let (res,_) = orphan_murder bag actives id in
- if res then debug "Orphan murdered"; res
+ if res then debug (lazy "Orphan murdered"); res
;;
let prof_orphan_murder = HExtlib.profile ~enable "orphan_murder";;
let orphan_murder bag actives x =
;;
(* demodulate and check for subsumption *)
- let simplify table maxvar bag clause =
- if is_identity_clause ~unify:false clause then bag,None
+ let simplify table maxvar bag clause =
+ debug (lazy "simplify...");
+ if is_identity_clause clause then bag,None
(* else if orphan_murder bag actives clause then bag,None *)
else let bag, clause = demodulate bag clause table in
- if is_identity_clause ~unify:false clause then bag,None
+ if is_identity_clause clause then bag,None
else
match is_subsumed ~unify:false bag maxvar clause table with
| None -> bag, Some clause
| bag,(None, Some _) -> bag,None
| bag,(Some cl1, Some (clause, (alist,atable), newa)) ->
let alist,atable =
- (clause::alist, IDX.index_unit_clause atable clause)
+ (clause::alist, IDX.index_unit_clause atable clause)
in
keep_simplified_aux ~new_cl:(cl!=cl1) cl1 (alist,atable)
bag (newa@tl)
let bag, clause =
if no_demod then bag, clause else demodulate bag clause table
in
- if List.exists (are_alpha_eq clause) g_actives then None else
- if (is_identity_clause ~unify:true clause)
- then raise (Success (bag, maxvar, clause))
- else
+ if List.exists (are_alpha_eq clause) g_actives then None
+ else match (is_identity_goal clause) with
+ | Some subst -> raise (Success (bag,maxvar,clause,subst))
+ | None ->
let (id,lit,vl,_) = clause in
- if vl = [] then Some (bag,clause)
+ (* this optimization makes sense only if we demodulated, since in
+ that case the clause should have been turned into an identity *)
+ if (vl = [] && not(no_demod))
+ then Some (bag,clause)
else
let l,r,ty =
match lit with
table (Some(bag,maxvar,clause,Subst.id_subst)) with
| None -> Some (bag,clause)
| Some (bag,maxvar,cl,subst) ->
- prerr_endline "Goal subsumed";
- raise (Success (bag,maxvar,cl))
+ debug (lazy "Goal subsumed");
+ raise (Success (bag,maxvar,cl,subst))
(*
- else match is_subsumed ~unify:true bag maxvar clause table with
+ match is_subsumed ~unify:true bag maxvar clause table with
| None -> Some (bag, clause)
| Some ((bag,maxvar),c) ->
prerr_endline "Goal subsumed";
raise (Success (bag,maxvar,c))
-*)
+*)
;;
let prof_simplify_goal = HExtlib.profile ~enable "simplify_goal";;
let side, newside = if dir=Terms.Left2Right then l,r else r,l in
try
let subst =
- Unif.unification (varlist@vl) [] subterm side
+ Unif.unification (* (varlist@vl)*) [] subterm side
in
- if o = Terms.Incomparable then
+ if o = Terms.Incomparable || o = Terms.Invertible then
let side = Subst.apply_subst subst side in
let newside = Subst.apply_subst subst newside in
let o = Order.compare_terms side newside in
(all_positions [3]
(fun x -> Terms.Node [ Terms.Leaf B.eqP; ty; l; x ])
r (superposition table vl))
+ | Terms.Equation (l,r,ty,Terms.Invertible)
| Terms.Equation (l,r,ty,Terms.Gt) ->
fold_build_new_clause bag maxvar id Terms.Superposition
(fun _ -> true)
(all_positions [2]
(fun x -> Terms.Node [ Terms.Leaf B.eqP; ty; x; r ])
l (superposition table vl))
- | Terms.Equation (l,r,ty,Terms.Incomparable) ->
- fold_build_new_clause bag maxvar id Terms.Superposition
- (function (* Riazanov: p.33 condition (iv) *)
- | Terms.Node [Terms.Leaf eq; ty; l; r ] when B.eq B.eqP eq ->
- Order.compare_terms l r <> Terms.Eq
- | _ -> assert false)
- ((all_positions [3]
- (fun x -> Terms.Node [ Terms.Leaf B.eqP; ty; l; x ])
- r (superposition table vl)) @
- (all_positions [2]
- (fun x -> Terms.Node [ Terms.Leaf B.eqP; ty; x; r ])
- l (superposition table vl)))
+ | Terms.Equation (l,r,ty,Terms.Incomparable) ->
+ let filtering avoid subst = (* Riazanov: p.33 condition (iv) *)
+ let l = Subst.apply_subst subst l in
+ let r = Subst.apply_subst subst r in
+ let o = Order.compare_terms l r in
+ o <> avoid && o <> Terms.Eq
+ in
+ let bag, maxvar,r_terms =
+ fold_build_new_clause bag maxvar id Terms.Superposition
+ (filtering Terms.Gt)
+ (all_positions [3]
+ (fun x -> Terms.Node [ Terms.Leaf B.eqP; ty; l; x ])
+ r (superposition table vl))
+ in
+ let bag, maxvar, l_terms =
+ fold_build_new_clause bag maxvar id Terms.Superposition
+ (filtering Terms.Lt)
+ (all_positions [2]
+ (fun x -> Terms.Node [ Terms.Leaf B.eqP; ty; x; r ])
+ l (superposition table vl))
+ in
+ bag, maxvar, r_terms @ l_terms
| _ -> assert false
;;
in
bag, (alist, List.fold_left IDX.index_unit_clause IDX.DT.empty alist)
in*)
- debug "Simplified active clauses with fact";
+ debug (lazy "Simplified active clauses with fact");
(* We superpose active clauses with current *)
let bag, maxvar, new_clauses =
List.fold_left
bag, maxvar, newc @ acc)
(bag, maxvar, []) alist
in
- debug "First superpositions";
+ debug (lazy "First superpositions");
(* We add current to active clauses so that it can be *
* superposed with itself *)
let alist, atable =
current :: alist, IDX.index_unit_clause atable current
in
- debug "Indexed";
+ debug (lazy "Indexed");
let fresh_current, maxvar = Utils.fresh_unit_clause maxvar current in
(* We need to put fresh_current into the bag so that all *
* variables clauses refer to are known. *)
let bag, maxvar, additional_new_clauses =
superposition_with_table bag maxvar fresh_current atable
in
- debug "Another superposition";
+ debug (lazy "Another superposition");
let new_clauses = new_clauses @ additional_new_clauses in
- debug (Printf.sprintf "Demodulating %d clauses"
- (List.length new_clauses));
+ (* debug (lazy (Printf.sprintf "Demodulating %d clauses"
+ (List.length new_clauses))); *)
let bag, new_clauses =
HExtlib.filter_map_monad (simplify atable maxvar) bag new_clauses
in
- debug "Demodulated new clauses";
+ debug (lazy "Demodulated new clauses");
bag, maxvar, (alist, atable), new_clauses
;;
let bag, maxvar, new_goals =
superposition_with_table bag maxvar goal atable
in
- debug "Superposed goal with active clauses";
+ debug(lazy "Superposed goal with active clauses");
(* We simplify the new goals with active clauses *)
let bag, new_goals =
List.fold_left
| Some (bag,g) -> bag,g::acc)
(bag, []) new_goals
in
- debug "Simplified new goals with active clauses";
+ debug (lazy "Simplified new goals with active clauses");
bag, maxvar, List.rev new_goals
;;
projects / helm.git / blobdiff