ref: cf81dd19f0c898fa6036d1f88cbe822eb8a2b4bf
dir: /test/occur.myr/
use std /* checks that f is not an infinite type (ie, the type doesn't exist within itself). If 'f' typechecked, it's type would be: f : (std.exit((-> (-> ... ad infinitum ...)))) */ const f = { std.exit(f) }