proposition: Lemma chain_rule_RV : `H(X, Y) = `H `p_X + `H(Y | X).
proof: Proof. rewrite /joint_entropy_RV. rewrite chain_rule fst_RV2. congr (_ + _). by rewrite fdistX_RV2. Qed.
imports: mathcomp(all_ssreflect all_algebra fingroup perm matrix) Reals mathcomp(Rstruct) ssrR Reals_ext realType_ext ssr_ext ssralg_ext bigop_ext logb ln_facts fdist jfdist_cond proba binary_entropy_function divergence