(VAR f x xs y)
(RULES
  app(app(map, f), nil) -> nil
  app(app(map, f), app(app(cons, x), xs)) -> app(app(cons, app(f, x)), app(app(map, f), xs))
  app(app(minus, x), 0) -> x
  app(app(minus, app(s, x)), app(s, y)) -> app(app(minus, app(p, app(s, x))), app(p, app(s, y)))
  app(p, app(s, x)) -> x
  app(app(div, 0), app(s, y)) -> 0
  app(app(div, app(s, x)), app(s, y)) -> app(s, app(app(div, app(app(minus, x), y)), app(s, y)))
)