proposition: Lemma fimfun_prod I r (P : {pred I}) (f : I -> {fimfun aT >-> rT}) (x : aT) : (\sum_(i <- r | P i) f i) x = \sum_(i <- r | P i) f i x.
proof: Proof. by elim/big_rec2: _ => //= i y ? Pi <-. Qed.
imports: HB(structures) mathcomp(all_ssreflect ssralg ssrnum ssrint interval finmap) mathcomp(mathcomp_extra boolp classical_sets fsbigop) mathcomp(functions cardinality set_interval) signed reals ereal topology normedtype sequences