proposition: Lemma conjg_Rmul x y : x ^ y = [~ y, x^-1] * x.
proof: Proof. by rewrite commgEr invgK mulgKV. Qed.
imports: mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat fintype) mathcomp(bigop finset binomial fingroup morphism) mathcomp(automorphism quotient gfunctor)