proposition: Lemma eq_symconnect r1 r2 : r1 =2 r2 -> symconnect r1 =2 symconnect r2.
proof: Proof. by move=> r1Er2 x y; rewrite /symconnect !(eq_connect r1Er2). Qed.
imports: mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice fintype tuple) mathcomp(bigop finset finfun perm fingraph path div) bigmin