The elements of this monoid kind of look like type signatures for Forth words. I was already playing with the idea of a sort of concurrent forth-like where each

The elements of this monoid kind of look like type signatures for Forth words. I was already playing with the idea of a sort of concurrent forth-like where each word sort of gets its own stack context. I'm really interested in neat models that provide partial evaluation, so I will be giving this some thought.