TRS:
 {         gt(0(), y) -> false(),
        gt(s(x), 0()) -> true(),
       gt(s(x), s(y)) -> gt(x, y),
         plus(0(), y) -> y,
        plus(s(x), y) -> s(plus(x, y)),
          double(0()) -> 0(),
         double(s(x)) -> s(s(double(x))),
        average(x, y) -> aver(plus(x, y), 0()),
         aver(sum, z) -> if(gt(sum, double(z)), sum, z),
   if(true(), sum, z) -> aver(sum, s(z)),
  if(false(), sum, z) -> z}
 Fail