struct
module IDX = Index.Index(B)
module Unif = FoUnif.Founif(B)
- module Subst = FoSubst (*.Subst(B)*)
+ module Subst = FoSubst
module Order = Orderings.Orderings(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 s = prerr_endline s;;
+ let debug _ = ();;
let rec list_first f = function
| [] -> None
;;
let first_position pos ctx t f =
+ let inject_pos pos ctx = function
+ | None -> None
+ | Some (a,b,c,d,e) -> Some(ctx a,b,c,d,e,pos)
+ in
let rec aux pos ctx = function
- | Terms.Leaf _ as t -> f t pos ctx
+ | Terms.Leaf _ as t -> inject_pos pos ctx (f t)
| Terms.Var _ -> None
| Terms.Node l as t->
- match f t pos ctx with
- | Some _ as x -> x
+ match f t with
+ | Some _ as x -> inject_pos pos ctx x
| None ->
let rec first pre post = function
| [] -> None
aux pos ctx t
;;
- let vars_of_term t =
- let rec aux acc = function
- | Terms.Leaf _ -> acc
- | Terms.Var i -> if (List.mem i acc) then acc else i::acc
- | Terms.Node l -> List.fold_left aux acc l
- in aux [] t
+ let parallel_positions bag pos ctx id t f =
+ 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->
+ let bag,t,id1 = f bag t pos ctx id in
+ if id = id1 then
+ 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 t in
+ if post = [] then bag, pre@[newt], [], id
+ else bag, pre @ [newt], List.tl post, id)
+ (bag, [], List.tl l, id) l
+ in
+ bag, Terms.Node l, id
+ else bag,t,id1
+ in
+ aux bag pos ctx id t
;;
let build_clause bag filter rule t subst vl id id2 pos dir =
| t -> Terms.Predicate t
in
let bag, uc =
- Utils.add_to_bag bag (0, literal, vars_of_term t, proof)
+ Terms.add_to_bag (0, literal, Terms.vars_of_term t, proof) bag
in
Some (bag, uc)
else
(* ============ simplification ================= *)
- let demod table varlist subterm pos context =
+ let demod table varlist subterm =
let cands = IDX.DT.retrieve_generalizations table subterm in
list_first
(fun (dir, (id,lit,vl,_)) ->
let subst, varlist =
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 = Subst.apply_subst subst side in
- let newside = Subst.apply_subst subst newside in
let o = Order.compare_terms newside side in
(* Riazanov, pp. 45 (ii) *)
if o = Terms.Lt then
- Some (context newside, subst, varlist, id, pos, dir)
+ Some (newside, subst, varlist, id, dir)
else
((*prerr_endline ("Filtering: " ^
Pp.pp_foterm side ^ " =(< || =)" ^
Pp.pp_foterm newside ^ " coming from " ^
Pp.pp_unit_clause uc );*)None)
else
- Some (context newside, subst, varlist, id, pos, dir)
+ Some (newside, subst, varlist, id, dir)
with FoUnif.UnificationFailure _ -> None)
(IDX.ClauseSet.elements cands)
;;
- let demodulate_once ~jump_to_right bag (id, literal, vl, pr) table =
- (* debug ("Demodulating : " ^ (Pp.pp_unit_clause (id, literal, vl, pr)));*)
+ let demodulate_once_old ~jump_to_right bag (id, literal, vl, pr) table =
match literal with
| Terms.Predicate t -> assert false
| Terms.Equation (l,r,ty,_) ->
(demod table vl)
in
match left_position with
- | Some (newt, subst, varlist, id2, pos, dir) ->
+ | Some (newt, subst, varlist, id2, dir, pos) ->
begin
match build_clause bag (fun _ -> true) Terms.Demodulation
newt subst varlist id id2 pos dir
(demod table vl)
with
| None -> None
- | Some (newt, subst, varlist, id2, pos, dir) ->
+ | Some (newt, subst, varlist, id2, dir, pos) ->
match build_clause bag (fun _ -> true)
Terms.Demodulation newt subst varlist id id2 pos dir
with
| Some x -> Some (x,true)
;;
+ let parallel_demod table vl bag t pos ctx id =
+ match demod table vl t with
+ | None -> (bag,t,id)
+ | Some (newside, subst, vl, id2, dir) ->
+ match build_clause bag (fun _ -> true)
+ Terms.Demodulation (ctx newside) subst vl id id2 pos dir
+ with
+ | None -> assert false
+ | Some (bag,(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
bag clause table
;;
- let demodulate bag clause table = demodulate ~jump_to_right:false
- 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
+ | Terms.Predicate _ -> assert false
+ | Terms.Equation (l,r,ty,_) ->
+ Terms.Node [Terms.Leaf B.eqP; ty; l ; r]
+ in
+ try ignore(Unif.alpha_eq (get_term cl1) (get_term cl2)) ; true
+ 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*)
;;
(* move away *)
let rec deep_eq ~unify l r ty pos contextl contextr table acc =
match acc with
| None -> None
- | Some(bag,maxvar,[],subst) -> assert false
- | Some(bag,maxvar,(id,_,vl,_)::clauses,subst) ->
+ | Some(bag,maxvar,(id,lit,vl,p),subst) ->
let l = Subst.apply_subst subst l in
let r = Subst.apply_subst subst r in
try
let subst1,vl1 = Unif.unification vl [] l r in
- Some(bag,maxvar,clauses,Subst.concat subst1 subst)
+ let lit =
+ match lit with Terms.Predicate _ -> assert false
+ | Terms.Equation (l,r,ty,o) ->
+ Terms.Equation (FoSubst.apply_subst subst1 l,
+ FoSubst.apply_subst subst1 r, ty, o)
+ in
+ Some(bag,maxvar,(id,lit,vl1,p),Subst.concat subst1 subst)
with FoUnif.UnificationFailure _ ->
match rewrite_eq ~unify l r ty vl table with
| Some (id2, dir, subst1) ->
+ let newsubst = Subst.concat subst1 subst in
let id_t =
- Terms.Node[Terms.Leaf B.eqP;ty;contextl r;contextr r] in
+ FoSubst.apply_subst newsubst
+ (Terms.Node[Terms.Leaf B.eqP;ty;contextl r;contextr r])
+ in
(match
build_new_clause bag maxvar (fun _ -> true)
- Terms.Superposition id_t subst1 [] id id2 (2::pos) dir
+ Terms.Superposition id_t
+ subst1 [] id id2 (pos@[2]) dir
with
| Some ((bag, maxvar), c) ->
- Some(bag,maxvar,c::clauses,Subst.concat subst1 subst)
+ Some(bag,maxvar,c,newsubst)
| None -> assert false)
| None ->
match l,r with
footail postl, footail postr))
(acc,[a],List.tl la,List.tl lb) la lb
in acc
- | Terms.Var _, _
- | _, Terms.Var _ -> assert false
| _,_ -> None
;;
+ let rec orphan_murder bag acc i =
+ match Terms.get_from_bag i bag with
+ | (_,_,_,Terms.Exact _),discarded,_ -> (discarded,acc)
+ | (_,_,_,Terms.Step (_,i1,i2,_,_,_)),true,_ -> (true,acc)
+ | (_,_,_,Terms.Step (_,i1,i2,_,_,_)),false,_ ->
+ if (List.mem i acc) then (false,acc)
+ else match orphan_murder bag acc i1 with
+ | (true,acc) -> (true,acc)
+ | (false,acc) ->
+ let (res,acc) = orphan_murder bag acc i2 in
+ if res then res,acc else res,i::acc
+ ;;
+
+ let orphan_murder bag actives cl =
+ 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
+ ;;
+
(* demodulate and check for subsumption *)
let simplify table maxvar bag clause =
- let bag, clause = demodulate bag clause table in
+ if is_identity_clause ~unify:false 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
else
match is_subsumed ~unify:false bag maxvar clause table with
| Some _ -> bag, None
;;
+ let simplify table maxvar bag clause =
+ match simplify table maxvar bag clause with
+ | bag, None ->
+ let (id,_,_,_) = clause in
+ let (_,_,iter) = Terms.get_from_bag id bag in
+ Terms.replace_in_bag (clause,true,iter) bag, None
+ | bag, Some clause -> bag, Some clause
+ (*let (id,_,_,_) = clause in
+ if orphan_murder bag clause then
+ Terms.M.add id (clause,true) bag, Some clause
+ else bag, Some clause*)
+ ;;
+
let one_pass_simplification new_clause (alist,atable) bag maxvar =
match simplify atable maxvar bag new_clause with
- | bag,None -> None (* new_clause has been discarded *)
+ | bag,None -> bag,None (* new_clause has been discarded *)
| bag,(Some clause) ->
let ctable = IDX.index_unit_clause IDX.DT.empty clause in
let bag, alist, atable =
List.fold_left
- (fun (bag, alist, atable as acc) c ->
+ (fun (bag, alist, atable) c ->
match simplify ctable maxvar bag c with
- |bag,None -> acc (* an active clause as been discarded *)
+ |bag,None -> (bag,alist,atable)
+ (* an active clause as been discarded *)
|bag,Some c1 ->
bag, c :: alist, IDX.index_unit_clause atable c)
(bag,[],IDX.DT.empty) alist
in
- Some (clause, bag, (alist,atable))
+ bag, Some (clause, (alist,atable))
;;
let simplification_step ~new_cl cl (alist,atable) bag maxvar new_clause =
(* Simplification of new_clause with : *
* - actives and cl if new_clause is not cl *
* - only actives otherwise *)
- match simplify atable1 maxvar bag new_clause with
- | bag,None -> (Some cl, None) (* new_clause has been discarded *)
+ match
+ simplify atable1 maxvar bag new_clause with
+ | bag,None -> bag,(Some cl, None) (* new_clause has been discarded *)
| bag,Some clause ->
(* Simplification of each active clause with clause *
* which is the simplified form of new_clause *)
let ctable = IDX.index_unit_clause IDX.DT.empty clause in
let bag, newa, alist, atable =
List.fold_left
- (fun (bag, newa, alist, atable as acc) c ->
+ (fun (bag, newa, alist, atable) c ->
match simplify ctable maxvar bag c with
- |bag,None -> acc (* an active clause as been discarded *)
+ |bag,None -> (bag, newa, alist, atable)
+ (* an active clause as been discarded *)
|bag,Some c1 ->
if (c1 == c) then
bag, newa, c :: alist,
(bag,[],[],IDX.DT.empty) alist
in
if new_cl then
- (Some cl, Some (clause, (alist,atable), newa, bag))
+ bag, (Some cl, Some (clause, (alist,atable), newa))
else
(* if new_clause is not cl, we simplify cl with clause *)
match simplify ctable maxvar bag cl with
| bag,None ->
(* cl has been discarded *)
- (None, Some (clause, (alist,atable), newa, bag))
+ bag,(None, Some (clause, (alist,atable), newa))
| bag,Some cl1 ->
- (Some cl1, Some (clause, (alist,atable), newa, bag))
+ bag,(Some cl1, Some (clause, (alist,atable), newa))
;;
let keep_simplified cl (alist,atable) bag maxvar =
let rec keep_simplified_aux ~new_cl cl (alist,atable) bag newc =
if new_cl then
match simplification_step ~new_cl cl (alist,atable) bag maxvar cl with
- | (None, _) -> assert false
- | (Some _, None) -> None
- | (Some _, Some (clause, (alist,atable), newa, bag)) ->
+ | _,(None, _) -> assert false
+ | bag,(Some _, None) -> bag,None
+ | bag,(Some _, Some (clause, (alist,atable), newa)) ->
keep_simplified_aux ~new_cl:(cl!=clause) clause (alist,atable)
bag (newa@newc)
else
match newc with
- | [] -> Some (cl, bag, (alist,atable))
+ | [] -> bag, Some (cl, (alist,atable))
| hd::tl ->
match simplification_step ~new_cl cl
(alist,atable) bag maxvar hd with
- | (None,None) -> assert false
- | (Some _,None) ->
+ | _,(None,None) -> assert false
+ | bag,(Some _,None) ->
keep_simplified_aux ~new_cl cl (alist,atable) bag tl
- | (None, Some _) -> None
- | (Some cl1, Some (clause, (alist,atable), newa, bag)) ->
+ | bag,(None, Some _) -> bag,None
+ | bag,(Some cl1, Some (clause, (alist,atable), newa)) ->
let alist,atable =
(clause::alist, IDX.index_unit_clause atable clause)
in
keep_simplified_aux ~new_cl:true cl (alist,atable) bag []
;;
- let are_alpha_eq cl1 cl2 =
- let get_term (_,lit,_,_) =
- match lit with
- | Terms.Predicate _ -> assert false
- | Terms.Equation (l,r,ty,_) ->
- Terms.Node [Terms.Leaf B.eqP; ty; l ; r]
- in
- try ignore(Unif.alpha_eq (get_term cl1) (get_term cl2)) ; true
- with FoUnif.UnificationFailure _ -> false
-;;
-
(* this is like simplify but raises Success *)
- let simplify_goal maxvar table bag g_actives clause =
- let bag, clause = demodulate bag clause table in
+ let simplify_goal ~no_demod maxvar table bag g_actives clause =
+ 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
let (id,lit,vl,_) = clause in
- let l,r,ty =
- match lit with
- | Terms.Equation(l,r,ty,_) -> l,r,ty
- | _ -> assert false
- in
- match deep_eq ~unify:true l r ty [] (fun x -> x) (fun x -> x)
- table (Some(bag,maxvar,[clause],Subst.id_subst)) with
- | None ->
- if List.exists (are_alpha_eq clause) g_actives then None
- else Some (bag, clause)
- | Some (bag,maxvar,cl,subst) ->
- debug "Goal subsumed";
- raise (Success (bag,maxvar,List.hd cl))
-*)
+ if vl = [] then Some (bag,clause)
+ else
+ let l,r,ty =
+ match lit with
+ | Terms.Equation(l,r,ty,_) -> l,r,ty
+ | _ -> assert false
+ in
+ match deep_eq ~unify:true l r ty [] (fun x -> x) (fun x -> x)
+ 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))
+(*
else match is_subsumed ~unify:true bag maxvar clause table with
- | None ->
- if List.exists (are_alpha_eq clause) g_actives then None
- else Some (bag, clause)
+ | None -> Some (bag, clause)
| Some ((bag,maxvar),c) ->
- debug "Goal subsumed";
- raise (Success (bag,maxvar,c))
+ prerr_endline "Goal subsumed";
+ raise (Success (bag,maxvar,c))
+*)
;;
(* =================== inference ===================== *)
else
((*prerr_endline ("Filtering: " ^
Pp.pp_foterm side ^ " =(< || =)" ^
- Pp.pp_foterm newside ^ " coming from " ^
- Pp.pp_unit_clause uc );*)None)
+ Pp.pp_foterm newside);*)None)
else
Some (context newside, subst, varlist, id, pos, dir)
with FoUnif.UnificationFailure _ -> None)
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, fresh_current = Utils.add_to_bag bag fresh_current in
+ let bag, fresh_current = Terms.add_to_bag fresh_current bag in
(* We superpose current with active clauses *)
let bag, maxvar, additional_new_clauses =
superposition_with_table bag maxvar fresh_current atable
let infer_left bag maxvar goal (_alist, atable) =
(* We superpose the goal with active clauses *)
+ if (match goal with (_,_,[],_) -> true | _ -> false) then bag, maxvar, []
+ else
let bag, maxvar, new_goals =
superposition_with_table bag maxvar goal atable
in
let bag, new_goals =
List.fold_left
(fun (bag, acc) g ->
- match simplify_goal maxvar atable bag [] g with
+ match simplify_goal ~no_demod:false maxvar atable bag [] g with
| None -> assert false
| Some (bag,g) -> bag,g::acc)
(bag, []) new_goals
projects / helm.git / blobdiff