proposition: Lemma prodr_undup_exp_count (I : eqType) r (P : pred I) (F : I -> R) : \prod_(i <- undup r | P i) F i ^+ count_mem i r = \prod_(i <- r | P i) F i.
proof: Proof. exact: big_undup_iterop_count. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat div seq) mathcomp(choice fintype finfun bigop prime binomial)