proposition: Lemma E_neg_RV : `E (`-- X) = - `E X.
proof: Proof. by rewrite /Ex/= big_morph_oppR/=; apply: eq_bigr => u _; rewrite mulNR. Qed.
imports: mathcomp(all_ssreflect ssralg ssrnum matrix) mathcomp(Rstruct reals) Reals Lra ssrR Reals_ext realType_ext logb ssr_ext ssralg_ext bigop_ext fdist