proposition: Lemma integral0 D : \int_(x in D) (cst 0 x) = 0.
proof: Proof. by rewrite ge0_integralE// erestrict0 nnintegral0. Qed.
imports: HB(structures) mathcomp(all_ssreflect ssralg ssrnum ssrint interval finmap) mathcomp(mathcomp_extra boolp classical_sets functions) mathcomp(cardinality fsbigop ) signed reals ereal topology normedtype sequences real_interval esum measure lebesgue_measure numfun