+type rank = { td : StateSet.t;
+ bu : StateSet.t;
+ exit : StateSet.t }
+
+val get_states_by_rank : t -> rank array
+(** return an array of states (sources, states) ordered by ranks.
+*)
+
+val get_max_rank : t -> int
+(** return the maximal rank of a state in the automaton, that is the
+ maximum number of runs needed to fuly evaluate the automaton.
+*)
+