proposition: Lemma nat_of_rV_ord0 (y : 'rV_0) : nat_of_rV y = O.
proof: Proof. by rewrite /nat_of_rV Nto_natE tuple_of_row_ord0. Qed.
imports: mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(fintype tuple) BinPos BinNat PArith ssr_ext mathcomp(bigop zmodp ssralg matrix) ssralg_ext f2