proposition: Lemma biglub_bigcup (I : Type) (S : neset I) (F : I -> neset L) : |_| (\bigcup_(i in S) F i)%:ne = |_| (biglub @` (F @` S))%:ne.
proof: Proof. by rewrite biglub_bignesetU. Qed.
imports: HB(structures) Reals mathcomp(all_ssreflect ssralg ssrnum) mathcomp(mathcomp_extra boolp classical_sets Rstruct reals) mathcomp(finmap) Reals_ext realType_ext classical_sets_ext ssrR fdist fsdist convex