proposition: Lemma measurable_indic d (T : measurableType d) (R : realType) (D A : set T) : measurable A -> measurable_fun D (\1_A : T -> R).
proof: Proof. by move=> mA; apply/measurable_funTS; rewrite (_ : \1__ = mindic R mA). 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