proposition: Lemma fdist_prod_of_fdist_rV n (P : fdist R A) : fdist_prod_of_rV (P `^ n.+1) = P `x P `^ n.
proof: Proof. apply/fdist_ext => /= -[a b]. rewrite fdist_prod_of_rVE /= fdist_rVS fdist_prodE; congr (P _ * P `^ n _) => /=. by rewrite row_mx_row_ord0. by rewrite rbehead_row_mx. 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