Formalization of the interpreter

The interpreter needs to be formalized once the operational semantics is finished. This is a necessary step towards writing TransLucid in TransLucid. The key missing parts for writing TL in TL are:

1. Besfitting
2. Parsing (a form of bestfitting)
3. Printing (a form of bestfitting)
4, Libraries

We are close on all of these. But nothing is finalized.