Input TRS: 1: app(nil(),y) -> y 2: app(add(n,x),y) -> add(n,app(x,y)) 3: reverse(nil()) -> nil() 4: reverse(add(n,x)) -> app(reverse(x),add(n,nil())) 5: shuffle(nil()) -> nil() 6: shuffle(add(n,x)) -> add(n,shuffle(reverse(x))) Number of Rules: 6 Direct POLO(Sum) ... removes: 5 I(nil) = 0 I(app) = x1 + x2 I(add) = x1 + x2 I(reverse) = x1 I(shuffle) = x1 + 1 Number of Rules: 5 Direct POLO(Sum) ...Direct QLPOS ...Direct QKBOS ... failed.