Semantic Subtyping

Theoretical work on semantic subtyping was a great source of inspiration. However, the implementation of ALT does not use any of the algorithms that where the result of this research.

It is clear however, that set-theoretic types are firmly routed in theory. May be it will turn out that the current implementation is faulty and broken beyond repair. Then it is good to know that we can fall back to semantic sub typing and their algorithms.