(VAR f x xs y z ) (RULES app(app(., 1), x) -> x app(app(., x), 1) -> x app(app(., app(i, x)), x) -> 1 app(app(., x), app(i, x)) -> 1 app(app(., app(i, y)), app(app(., y), z)) -> z app(app(., y), app(app(., app(i, y)), z)) -> z app(app(., app(app(., x), y)), z) -> app(app(., x), app(app(., y), z)) app(i, 1) -> 1 app(i, app(i, x)) -> x app(i, app(app(., x), y)) -> app(app(., app(i, y)), app(i, x)) 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) )