+ if PassiveSet.is_empty g_passives then
+ (false,snd cl,PassiveSet.remove cl passives,g_passives)
+ else
+ let g_cl = PassiveSet.min_elt g_passives in
+ if (fst cl <= fst g_cl) then
+ (false,snd cl,PassiveSet.remove cl passives,g_passives)
+ else
+ (true,snd g_cl,passives,PassiveSet.remove g_cl g_passives)
+ in
+
+ let backward_infer_step bag maxvar actives passives g_actives g_passives g_current =
+ (* superposition left, simplifications on goals *)
+ debug "infer_left step...";
+ debug ("Selected goal : " ^ Pp.pp_unit_clause g_current);
+ let bag, g_current =
+ Sup.simplify_goal maxvar (snd actives) bag g_current
+ in
+ debug "Simplified goal";
+ let bag, maxvar, new_goals =
+ Sup.infer_left bag maxvar g_current actives
+ in
+ debug "Performed infer_left step";
+ let new_goals = List.fold_left add_passive_clause
+ PassiveSet.empty new_goals
+ in
+ bag, maxvar, actives, passives, g_current::g_actives,
+ (PassiveSet.union new_goals g_passives)
+ in
+
+ let forward_infer_step bag maxvar actives passives g_actives
+ g_passives current =
+ (* forward step *)
+
+ (* e = select P *
+ * e' = demod A e *
+ * A' = demod [e'] A *
+ * A'' = A' + e' *
+ * e'' = fresh e' *
+ * new = supright e'' A'' *
+ * new'= demod A'' new *
+ * P' = P + new' *)
+ debug "Forward infer step...";
+ debug "Selected and simplified";
+ (* debug ("Fact after simplification :"
+ ^ Pp.pp_unit_clause current); *)
+ let bag, maxvar, actives, new_clauses =
+ Sup.infer_right bag maxvar current actives
+ in
+ debug "Demodulating goals with actives...";
+ debug ("Current : " ^ (Pp.pp_unit_clause current));
+ debug ("Active goal : " ^ (Pp.pp_unit_clause (List.hd g_actives)));
+ (* keep goals demodulated w.r.t. actives and check if solved *)
+ let bag, g_actives =
+ List.fold_left
+ (fun (bag,acc) c ->
+ let bag, c = Sup.simplify_goal maxvar (snd actives) bag c in
+ bag, c::acc)
+ (bag,[]) g_actives
+ in
+ debug (Pp.pp_unit_clause current);
+ debug (Pp.pp_unit_clause (List.hd g_actives));
+ let ctable = IDX.index_unit_clause IDX.DT.empty current in
+ let bag, maxvar, new_goals =
+ List.fold_left
+ (fun (bag,m,acc) g ->
+ let bag, m, ng = Sup.infer_left bag m g
+ ([current],ctable) in
+ bag,m,ng@acc)
+ (bag,maxvar,[]) g_actives
+ in
+ let new_clauses = List.fold_left add_passive_clause
+ PassiveSet.empty new_clauses in
+ let new_goals = List.fold_left add_passive_clause
+ PassiveSet.empty new_goals in
+ debug (string_of_int (PassiveSet.cardinal new_goals));
+ debug (string_of_int (PassiveSet.cardinal g_passives));
+ bag, maxvar, actives,
+ PassiveSet.union new_clauses passives, g_actives,
+ PassiveSet.union new_goals g_passives