proposition: Lemma rmorph_prod I r (P : pred I) E : f (\prod_(i <- r | P i) E i) = \prod_(i <- r | P i) f (E i).
proof: Proof. exact: (big_morph f rmorphM rmorph1). Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat div seq) mathcomp(choice fintype finfun bigop prime binomial)