proposition: Lemma fdistA21 : ((fdistA P)`2)`1 = (P`1)`2.
proof: Proof. by rewrite /fdistA /fdist_snd /fdist_fst /= !fdistmap_comp. 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