Canonical lin_mulmx_linear := Linear lin_mulmx_is_linear.
End AssocLeft.
Section LinMulRow.
Variables m n : nat.
Definition lin_mul_row u : 'M[R]_(m * n, n) := lin1_mx (mulmx u \o vec_mx).

(* Specifications: *)
Lemma lin_mul_row_is_linear : linear lin_mul_row.
Canonical lin_mul_row_additive := Additive lin_mul_row_is_linear.