proposition: Lemma measureU0 A B : measurable A -> measurable B -> mu B = 0 -> mu (A `|` B) = mu A.
proof: Proof. move=> mA mB B0; rewrite measureUfinr/= ?B0// adde0. by rewrite (@subset_measure0 _ _ _ _ (A `&` B) B) ?sube0//; exact: measurableI. 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)