proposition: Lemma symmetry : P |= X _|_ Y | Z -> P |= Y _|_ X | Z.
proof: Proof. move=> H b a c. rewrite /cinde_rv in H. rewrite cpr_eq_pairC. rewrite H. by rewrite mulRC. Qed.
imports: mathcomp(all_ssreflect ssralg matrix) Reals mathcomp(Rstruct) ssrR Reals_ext logb ssr_ext ssralg_ext bigop_ext fdist proba jfdist_cond