Lemma subvs_inj : injective vsval. Proof. exact: val_inj. Qed.
Lemma congr_subvs u v : u = v -> vsval u = vsval v.Proof. exact: congr1. Qed.

Lemma vsval_is_linear :f. by []. Qed.
Canonical vsval_additive := Additive vsval_is_linear.
Canonical vsval_linear := AddLinear vsval_is_linear.

Proof. by rewrite unlock; apply: projv_