Sorry, I am not familiar with Rust. Although I try hard to understand this library, I cannot say that I understand it.

I have two questions here:

1. How to express uncertain state in type. In my example, it is implemented by union (enum) + Witness https://github.com/sdzx-1/polystate-examples/blob/fecaffb5b7...

2. I don't seem to see the possibility of combining state machines