proposition: Lemma conjgM x y z : x ^ (y * z) = (x ^ y) ^ z.
proof: Proof. by rewrite !conjgE invMg !mulgA. Qed.
imports: HB(structures) mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat seq choice) mathcomp(fintype div path tuple bigop prime finset)