Canonical r2v_linear := Linear (can2_linear v2rK r2vK).
End Iso.
Section Vspace.
Variables (K : fieldType) (vT : vectType K).
Local Coercion dim : vectType >-> nat.
Definition b2mx n (X : n.-tuple vT) := \matrix_i v2r (tnth X i).

Lemma b2mxK n (X : n.-tuple vT) i : r2v (row i (b2mx X)) = X`_i.
Let lin_b2mx n (X : n.-tuple vT) k :
\sum_(i < n) k i *: X`_i = r2v (\row_i k i *m b2mx X).