proposition: Lemma P_fssum' A : P A = \esum_(k in A `&` [set` finsupp d]) (d k)%:E.
proof: Proof. rewrite /P esum_mkcondr. apply eq_esum => i _. rewrite mem_setE. by case: finsuppP. 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)