fact: Definition additive := forall F, (forall i : nat, measurable (F i)) -> trivIset setT F -> forall n, mu (\big[setU/set0]_(i < n) F i) = \sum_(i < n) mu (F i).
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)