proposition: Lemma addr_max_min x y : max x y + min x y = x + y.
proof: Proof. by rewrite addrC addr_min_max. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(ssrAC div fintype path bigop order finset fingroup) mathcomp(ssralg poly)