+val tag_operations : t -> Tag.operations
+
+val start_tag : t -> node -> tn_symbol
+val is_terminal : t -> [< any_type ] Node.t -> bool
+val is_non_terminal : t -> [< any_type ] Node.t -> bool
+external terminal : [< any_type ] Node.t -> t_symbol = "%identity"
+external non_terminal : [< any_type ] Node.t -> n_symbol = "%identity"
+val nil_symbol : t_symbol
+val tag : t_symbol -> Tag.t
+val start_first_child : t -> node -> node
+val start_next_sibling : t -> node -> node
+val get_rule : t -> n_symbol -> rhs
+val get_conf : rhs -> conf
+val get_rank : rhs -> int
+val get_id1_rank : rhs -> int
+val get_id2_rank : rhs -> int
+val get_id2_pos : rhs -> int
+val get_id1 : rhs -> tn_symbol
+val get_id2 : rhs -> tn_symbol