fact: Definition merge (G: graph) (r : equiv_rel G) := {| vertex := quot r; edge := edge G; endpoint b e := \pi (endpoint b e); vlabel c := \big[cm_op/1]_(w | \pi w == c) vlabel w; elabel e := elabel e |}.
imports: Coq(Morphisms RelationClasses) mathcomp(all_ssreflect) GraphTheory(edone finite_quotient preliminaries bij) GraphTheory(equiv digraph setoid_bigop structures)