val simplify :
Index.Index(B).DT.t ->
+ int ->
B.t Terms.bag ->
B.t Terms.unit_clause ->
(B.t Terms.bag * B.t Terms.unit_clause) option
B.t Terms.unit_clause ->
Index.Index(B).active_set ->
B.t Terms.bag ->
+ int ->
(B.t Terms.unit_clause * B.t Terms.bag * Index.Index(B).active_set) option
B.t Terms.unit_clause ->
Index.Index(B).active_set ->
B.t Terms.bag ->
+ int ->
(B.t Terms.unit_clause * B.t Terms.bag * Index.Index(B).active_set) option