#7: The end(-to-end) in sight

We have verified all of the "zero-order" functions but for main.

Next up

Our goal for the next iteration (to 20th) is to implement the code generation phase of Xr0. Our reason for this detour from verifying the Lex program is that in verifying the parser we have found ourselves making significant refactors to the code with which we are no longer sure that the program still functions as intended. Generating a working program will allow us to test end to end.

Goal:

1. Implement C code generation [#19]

Stretch goals:

1. Simplify map and array data structures [#13]

2. Write a first-version of the "topological sort" mechanism [#16].