fact: Definition preimage_classes d1 d2 (T1 : measurableType d1) (T2 : measurableType d2) (T : Type) (f1 : T -> T1) (f2 : T -> T2) := <<s preimage_class setT f1 measurable `|` preimage_class setT f2 measurable >>.
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)