proposition: Lemma d1 : \sum_(a <- finsupp d) d a = 1.
proof: Proof. by apply/eqP; case/andP: Hd. Qed.
imports: HB(structures) mathcomp(all_ssreflect ssralg ssrnum) mathcomp(finmap) Reals mathcomp(mathcomp_extra) mathcomp(classical_sets boolp cardinality Rstruct reals) mathcomp(ereal topology esum measure probability) ssrR realType_ext Reals_ext ssr_ext ssralg_ext bigop_ext fdist convex mathcomp(measure probability)