proposition: Lemma measurable_funeneg D (f : T -> \bar R) : measurable_fun D f -> measurable_fun D f^\-.
proof: Proof. by move=> mf; apply: measurable_maxe => //; exact: measurableT_comp. Qed.
imports: mathcomp(all_ssreflect ssralg ssrnum ssrint interval) mathcomp(finmap fingroup perm rat) mathcomp(mathcomp_extra boolp classical_sets functions) mathcomp(cardinality fsbigop) reals ereal signed topology numfun normedtype HB(structures) sequences esum measure real_interval realfun exp lebesgue_stieltjes_measure