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