proposition: Lemma fdistC12_RV3 : fdistC12 `p_[% X, Y, Z] = `p_[% Y, X, Z].
proof: Proof. by rewrite /fdistC12 /dist_of_RV fdistmap_comp. 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