 The upshot of the foregoing discussion is that most test spaces can’t be embedded into any classical test space, and that even where such an embedding exists, it typically fails to account for some of the model’s states. However, there is one very important class of models for which a satisfactory classical interpretation is always possible. Let us call a test space \(\mathcal{A}\) semi-classical if its tests do not overlap; i.e., if \(E \cap F = \varnothing\) for \(E, F \in \mathcal{A}\), with \(E\ne F\).