proposition: Lemma step_conodes_ok : part step_conodes = end_node |: conodes c.
proof: Proof. rewrite /step_conodes. destruct Bool.bool_dec => //. by rewrite Hcond /=. Qed.
imports: mathcomp(all_ssreflect ssralg fingroup zmodp poly ssrnum) mathcomp(matrix perm) ssr_ext ssralg_ext fdist subgraph_partition tanner