proposition: Lemma real_oppr_max : {in real &, {morph -%R : x y / max x y >-> min x y : R}}.
proof: Proof. by move=> x y xr yr; rewrite !(fun_if, if_arg) ltrN2; case: real_ltgtP => // ->. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(ssrAC div fintype path bigop order finset fingroup) mathcomp(ssralg poly)