> I wonder if you could make something like Afl-fuzz but point it at your test cases, until it brute-forces some code that makes all your tests pass :) You can throw the syntax of all the modules it should be using at it.

AIUI prolog kind of works like that. You give it what it can use and what it needs to produce, and it'll fill in the implementation.

(In practice it's slow as hell and figuring out how to tell it the information in the "right" way so that it can "figure out" the proper implementation is a black art.)