ref: 5518b9657c07d4ee93ac1db4c97b6d4ec164d42b
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) }