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