scales (cf. e.g. [@Isham]). In the following we want to develop such a model theory in more detail.

As far as we can see, such a philosophy is also shared by ‘t Hooft who emphasized this point in quite a few papers (see e.g. [@H1],[@H2],[@H3],[@H4]). We quote from [@H2]:

> […it may still be possible that the quantum mechanical nature of the phenomenological laws of nature at the atomic scale can be attributed to an underlying law that is deterministic at the Planck scale but with chaotic effects at all larger scales…Since, according to our philosophy, quantum states are identified with equivalence classes…]{}

Furthermore:

> […It is the author’s suspicion however, that these hidden variable theories failed because they were based far too much upon notions from everyday life and ‘ordinary physics’ and in particular because general relativistic effects have not been taken into account properly.]{}

While ’t Hooft usually chooses his model theories from the cellular automaton (CA) class, we are adopting a point of view which is on the one hand more general and flexible but, on the other hand, technically more difficult and complex. Instead of a relatively rigid underlying geometric substratum in the case of CA 