ref: 2fd5ae3c5599fdd067ed11f3a58fb03da587db28
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) }