fact: Definition mentions (A: eqType) (l: pairs A) := flatten [seq [::x.1;x.2] | x <- l].
imports: HB(structures) Coq(Setoid Morphisms) mathcomp(all_ssreflect) GraphTheory(edone finite_quotient preliminaries bij equiv) GraphTheory(setoid_bigop structures pttdom mgraph mgraph2 rewriting)