proposition: Lemma bigsetU_measurable I r (P : pred I) (F : I -> set T) : (forall i, P i -> measurable (F i)) -> measurable (\big[setU/set0]_(i <- r | P i) F i).
proof: Proof. by move=> mF; elim/big_ind : _ => //; exact: measurableU. 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)