Start a library for bootstrapped meta rules for "the mathematical notation"

[bvssvni]

The notation I use for reasoning about API designs is based on PistonDevelopers/piston#736. This notation has the benefit that it can express path semantics between functions without needing to encode that information into the types, so it is very easy to use for reasoning.

I have tested piston-meta by writing the rules manually and think it also would serve as a good test case for testing bootstrapping meta rules. With bootstrapped rules, we would have a better guess if there is a good idea to share a meta language across libraries. The bootstrapped rules for the mathematical notation could also open up possibilities for further research projects.

[bvssvni]

I've created https://github.com/PistonDevelopers/math_notation.

Closing.