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_baseAspace (E0 : {subfield L0}) :
(F1 <= E0)%VS -> {E | E0 = baseAspace E & E0 =i E}.