(VAR f x xs y ) (RULES app(app(times, x), 0) -> 0 app(app(times, x), app(s, y)) -> app(app(plus, app(app(times, x), y)), x) app(app(plus, x), 0) -> x app(app(plus, 0), x) -> x app(app(plus, x), app(s, y)) -> app(s, app(app(plus, x), y)) app(app(plus, app(s, x)), y) -> app(s, app(app(plus, 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)) app(app(filter, f), nil) -> nil app(app(filter, f), app(app(cons, x), xs)) -> app(app(app(app(filter2, app(f, x)), f), x), xs) app(app(app(app(filter2, true), f), x), xs) -> app(app(cons, x), app(app(filter, f), xs)) app(app(app(app(filter2, false), f), x), xs) -> app(app(filter, f), xs) )