Canonical baseAspace E := ASpace (baseAspace_suproof E).
Fact refBaseField_key : unit. Proof. by []. Qed.
Definition refBaseField := locked_with refBaseField_key (baseAspace 1).
Canonical refBaseField_unlockable := [unlockable of refBaseField].
Notation F1 := refBaseField.

Lemma module_baseVspace M0 :
(F1 * M0 <= M0)%VS -> {V | M0 = baseVspace V & M0 =i V}.