proposition: Lemma entropy_fdist_perm n (P : {fdist 'rV[A]_n}) (s : 'S_n) : `H (fdist_perm P s) = `H P.
proof: Proof. rewrite /entropy; congr (- _) => /=; apply/esym. rewrite (@reindex_inj _ _ _ _ (@col_perm _ _ _ s) xpredT); last first. exact: col_perm_inj. by apply eq_bigr => v _; rewrite fdist_permE. 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