Revive type class elaboration #2450
Description
We discovered recently (#2434) that some of the code to reason about type classes is not tested in the test suite. As discussed in the comments there, we have disabled tests that could be reenabled, and we have other tests that could be considered for inclusion.
A project idea has spontaneously materialized, then, where these tests could guide fixing of the code and improving the documentation. In addition, we also have a paper discussing how the code is intended to work [link].
The code in question is an implementation of section 3.2 of this paper. The paper should provide the context necessary to understand the purpose of this part of Liquid Haskell.
After the tests are passing, we could assess whether these tests and the others reasonably cover the paper's promises.