fact: Definition approxRN := [set g : T -> \bar R | [/\ forall x, 0 <= g x, mu.-integrable [set: T] g & forall E, measurable E -> \int[mu]_(x in E) g x <= nu E] ].
imports: mathcomp(all_ssreflect ssralg ssrnum ssrint interval) mathcomp(finmap fingroup perm rat) mathcomp(mathcomp_extra boolp classical_sets cardinality) mathcomp(functions fsbigop set_interval) HB(structures) reals ereal signed topology numfun normedtype sequences esum measure realfun lebesgue_measure lebesgue_integral