proposition: Lemma lift_permV i j s : (lift_perm i j s)^-1 = lift_perm j i s^-1.
proof: Proof. by apply/eqP; rewrite eq_invg_mul lift_permM mulgV lift_perm1. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq path) mathcomp(choice fintype tuple finfun bigop finset binomial) mathcomp(fingroup morphism)