proposition: Lemma poweRAC x r s : (x `^ r) `^ s = (x `^ s) `^ r.
proof: Proof. by rewrite -!poweRrM mulrC. Qed.
imports: mathcomp(all_ssreflect ssralg ssrint ssrnum matrix) mathcomp(interval rat) mathcomp(boolp classical_sets functions) mathcomp(mathcomp_extra) reals ereal signed topology normedtype landau sequences derive realfun itv convex