fact: Hypothesis eqvI : forall x (inU : x \in V1) (inV : x \in V2), inl (Sub x inU) = inr (Sub x inV) %[mod eqv_clot h].
imports: Coq(Morphisms RelationClasses) mathcomp(all_ssreflect) GraphTheory(edone finite_quotient preliminaries bij) GraphTheory(equiv digraph setoid_bigop structures)