Project files for miniKanren language levels, as outlined in my paper, Little Logic Languages for Relational Programming, presented at the Scheme and Functional Programming Workshop of 2014. From the abstract:
The miniKanren relational programming language, though designed and used as a language with which to teach relational programming, can be immensely frustrating when it comes to debugging programs, especially when the programmer is a novice. In order to address the varying levels of programmer sophistication, we introduce a suite of different language levels. We introduce the first of these languages, and provide experimental results that demonstrate its effectiveness in helping beginning programmers discover and prevent mistakes.