;;
(* move away *)
- let is_identity_clause = function
+ let is_identity_clause ~unify = function
| _, Terms.Equation (_,_,_,Terms.Eq), _, _ -> true
- | _, Terms.Equation (l,r,_,_), vl, proof ->
+ | _, Terms.Equation (l,r,_,_), vl, proof when unify ->
(try ignore(Unif.unification vl [] l r); true
with FoUnif.UnificationFailure _ -> false)
| _, Terms.Predicate _, _, _ -> assert false
+ | _ -> false
;;
let build_new_clause bag maxvar filter rule t subst vl id id2 pos dir =
(* demodulate and check for subsumption *)
let simplify table maxvar bag clause =
let bag, clause = demodulate bag clause table in
- if is_identity_clause clause then None
+ if is_identity_clause ~unify:false clause then bag,None
else
match is_subsumed ~unify:false bag maxvar clause table with
- | None -> Some (bag, clause)
- | Some _ -> None
+ | None -> bag, Some clause
+ | Some _ -> bag, None
;;
let one_pass_simplification new_clause (alist,atable) bag maxvar =
match simplify atable maxvar bag new_clause with
- | None -> None (* new_clause has been discarded *)
- | Some (bag, clause) ->
+ | bag,None -> 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 ->
match simplify ctable maxvar bag c with
- |None -> acc (* an active clause as been discarded *)
- |Some (bag, c1) ->
+ |bag,None -> acc (* an active clause as been discarded *)
+ |bag,Some c1 ->
bag, c :: alist, IDX.index_unit_clause atable c)
(bag,[],IDX.DT.empty) alist
in
* - 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) ->
+ | bag,None -> (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
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) ->
+ |bag,None -> acc (* an active clause as been discarded *)
+ |bag,Some c1 ->
if (c1 == c) then
bag, newa, c :: alist,
IDX.index_unit_clause atable c
else
(* if new_clause is not cl, we simplify cl with clause *)
match simplify ctable maxvar bag cl with
- | None ->
+ | bag,None ->
(* cl has been discarded *)
(None, Some (clause, (alist,atable), newa, bag))
- | Some (bag,cl1) ->
+ | bag,Some cl1 ->
(Some cl1, Some (clause, (alist,atable), newa, bag))
;;
(* this is like simplify but raises Success *)
let simplify_goal maxvar table bag g_actives clause =
let bag, clause = demodulate bag clause table in
- if (is_identity_clause clause)
+ if (is_identity_clause ~unify:true clause)
then raise (Success (bag, maxvar, clause))
else match is_subsumed ~unify:true bag maxvar clause table with
| None ->
debug (Printf.sprintf "Demodulating %d clauses"
(List.length new_clauses));
let bag, new_clauses =
- HExtlib.filter_map_acc (simplify atable maxvar) bag new_clauses
+ HExtlib.filter_map_monad (simplify atable maxvar) bag new_clauses
in
debug "Demodulated new clauses";
bag, maxvar, (alist, atable), new_clauses