(module poly_id
  (fn id
    (type (forall (vars a) (fn-type (params a) (ret a))))
    (params x)
    (body x))
  (fn main
    (type (fn-type (params) (ret (con Unit)) (effects IO)))
    (params)
    (body (seq (do io/print_int (app id 42)) (do io/print_bool (app id true))))))