Section AspaceTheory.
Variables (K : fieldType) (aT : FalgType K).
Implicit Types (u v e : aT) (U V : {vspace aT}) (A B : {aspace aT}).
Definition algid U := s2val (algid_subproof U).

Lemma prodv_sub U V A : (U <= A -> V <= A -> U * V <= A)%VS.