proposition: Lemma negligibleP A : measurable A -> mu.-negligible A <-> mu A = 0.
proof: Proof. move=> mA; split => [[B [mB mB0 AB]]|mA0]; last by exists A; split. by apply/eqP; rewrite -measure_le0 -mB0 le_measure ?inE. Qed.
imports: mathcomp(all_ssreflect all_algebra finmap) mathcomp(mathcomp_extra boolp classical_sets functions) mathcomp(cardinality fsbigop ) reals ereal signed topology normedtype sequences esum numfun HB(structures)