+ let simplification_step ~new_cl cl (alist,atable) bag maxvar new_clause =
+ let atable1 =
+ if new_cl then atable else
+ IDX.index_unit_clause atable cl
+ in
+ (* 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
+ | None -> (Some cl, None) (* new_clause has been discarded *)
+ | Some (bag, 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 ->
+ match simplify ctable maxvar bag c with
+ |None -> acc (* an active clause as been discarded *)
+ |Some (bag, c1) ->
+ if (c1 == c) then
+ bag, newa, c :: alist,
+ IDX.index_unit_clause atable c
+ else
+ bag, c1 :: newa, alist, atable)
+ (bag,[],[],IDX.DT.empty) alist
+ in
+ if new_cl then
+ (Some cl, Some (clause, (alist,atable), newa, bag))
+ else
+ (* if new_clause is not cl, we simplify cl with clause *)
+ match simplify ctable maxvar bag cl with
+ | None ->
+ (* cl has been discarded *)
+ (None, Some (clause, (alist,atable), newa, bag))
+ | Some (bag,cl1) ->
+ (Some cl1, Some (clause, (alist,atable), newa, bag))
+ ;;
+
+ 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)) ->
+ keep_simplified_aux ~new_cl:(cl!=clause) clause (alist,atable)
+ bag (newa@newc)
+ else
+ match newc with
+ | [] -> Some (cl, bag, (alist,atable))
+ | hd::tl ->
+ match simplification_step ~new_cl cl
+ (alist,atable) bag maxvar hd with
+ | (None,None) -> assert false
+ | (Some _,None) ->
+ keep_simplified_aux ~new_cl cl (alist,atable) bag tl
+ | (None, Some _) -> None
+ | (Some cl1, Some (clause, (alist,atable), newa, bag)) ->
+ let alist,atable =
+ (clause::alist, IDX.index_unit_clause atable clause)
+ in
+ keep_simplified_aux ~new_cl:(cl!=cl1) cl1 (alist,atable)
+ bag (newa@tl)
+ 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 =