module O: Defaultgraphs.GraphOper(G)
val transitive_reduction : G.t -> unit
transitive reduction. Uses the transitive reduction algorithm from The
Transitive Reduction of a Directed Graph, Aho, Garey and Ullman, 1972 -
with the proviso that we know that our graph already is a transitive
closure
module O: Graph.Oper.I(G)
module S: Set.Make(G.V)
val subgraph : G.t -> S.elt list -> G.t
extract the subgraph induced by the list l