ref: e119045a1d483c7dc7808c140a3659e41b9d160b
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 : (-> (-> (-> ... ad infinitum ...))) */ const f = { -> f }