proposition: Lemma comparable_arg_maxP: extremum_spec >=%O P F (arg_max i0 P F).
proof: Proof. apply: extremum_inP => // [x _|y x z _ _ _|]; [exact: lexx|exact: ge_trans|]. by move=> x y xP yP; rewrite orbC [_ || _]F_comparable. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat choice seq) mathcomp(path fintype tuple bigop finset div prime finfun) mathcomp(finset)