proposition: Lemma sum_fdist_binary_swap a : \sum_(a' in A) fdist_binary a a' = \sum_(a' in A) fdist_binary a' a.
proof: Proof. by rewrite 2!Set2sumE /= !fdist_binaryE !(eq_sym a). Qed.
imports: mathcomp(all_ssreflect ssralg fingroup perm matrix) mathcomp(all_algebra vector reals normedtype) mathcomp(mathcomp_extra boolp) mathcomp(Rstruct) ssrR logb realType_ext ssr_ext ssralg_ext bigop_ext