proposition: Lemma bigmax_idl P F : \big[max/x]_(i <- r | P i) F i = max x (\big[max/x]_(i <- r | P i) F i).
proof: Proof. by rewrite maxC big_id_idem //= maxxx. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat choice seq) mathcomp(path fintype tuple bigop finset div prime finfun) mathcomp(finset)