Strongly_connected_components.S

`sig
module Id : Identifiable.S
type directed_graph = Id.Set.t Id.Map.t
type component = Has_loop of Id.t list | No_loop of Id.t
val connected_components_sorted_from_roots_to_leaf :
Strongly_connected_components.S.directed_graph ->
Strongly_connected_components.S.component array
val component_graph :
Strongly_connected_components.S.directed_graph ->
(Strongly_connected_components.S.component * int list) array
end`