-val compteur : int ref
-(**the counter of nodes*)
+val query_tree_size : int ref
+(**the size of query_tree*)
val element_by_tag : Naive_tree.t -> QNameSet.t -> Tree.NodeKind.t -> Bitvector.t
(** [element_by_tag t tag] returns all the nodes whose tag equal to [tag] in the tree [t]. *)