0 QTRS
app(id, x) → x app(add, 0) → id app(app(add, app(s, x)), y) → app(s, app(app(add, x), y)) 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))