proposition: Lemma oarc_injR e x y y' u u' : oarc G e x u y -> oarc G e x u' y' -> y = y'.
proof: Proof. case => E [b] [? ? ?] [_ [b'] [? ? ?]]. subst. by destruct b; destruct b'. Qed.
imports: HB(structures) Coq(Relation_Definitions Morphisms RelationClasses) mathcomp(all_ssreflect) GraphTheory(edone finite_quotient preliminaries bij equiv) GraphTheory(setoid_bigop structures pttdom rewriting) GraphTheory(finmap_plus)