proposition: Lemma en_in_step_conodes : en \in step_conodes c sp ep en.
proof: Proof. by rewrite step_conodes_ok // !inE eqxx. Qed.
imports: mathcomp(all_ssreflect ssralg fingroup zmodp poly ssrnum) mathcomp(matrix perm) ssr_ext ssralg_ext fdist subgraph_partition tanner