Review higher-rank and impredicative types
The ticket is a placeholder to remind me to work through the test cases for impredicative and higher rank types in the new typechecker. For now, I'm marking many of them as
expect_broken on this ticket, although I think many of them really should fail.
- Many tests in
boxy/(see also #1330 (closed) for Church2)
- #2193 (closed)
- #2846 (closed)
- #4347 (closed)
- Lennart's blog post has an interesting use case of impredicative polymorphism; it worked in 7.0, but alas not in the new typechecker.