TRS: { app(x, y) -> helpa(0(), plus(length(x), length(y)), x, y), plus(x, 0()) -> x, plus(x, s(y)) -> s(plus(x, y)), length(nil()) -> 0(), length(cons(x, y)) -> s(length(y)), helpa(c, l, ys, zs) -> if(ge(c, l), c, l, ys, zs), ge(x, 0()) -> true(), ge(0(), s(x)) -> false(), ge(s(x), s(y)) -> ge(x, y), if(true(), c, l, ys, zs) -> nil(), if(false(), c, l, ys, zs) -> helpb(c, l, greater(ys, zs), smaller(ys, zs)), greater(ys, zs) -> helpc(ge(length(ys), length(zs)), ys, zs), smaller(ys, zs) -> helpc(ge(length(ys), length(zs)), zs, ys), helpc(true(), ys, zs) -> ys, helpc(false(), ys, zs) -> zs, helpb(c, l, cons(y, ys), zs) -> cons(y, helpa(s(c), l, ys, zs))} Fail