MAYBE
Trs:
 {ify(false(), x, y) -> divByZeroError(),
   ify(true(), x, y) -> if(ge(x, y), x, y),
       ge(0(), s(x)) -> false(),
      ge(s(x), s(y)) -> ge(x, y),
          ge(x, 0()) -> true(),
   if(false(), x, y) -> 0(),
    if(true(), x, y) -> s(div(minus(x, y), y)),
   minus(s(x), s(y)) -> minus(x, y),
       minus(x, 0()) -> x,
           div(x, y) -> ify(ge(y, s(0())), x, y)}
 Comment:
  We consider a duplicating trs.
  FAIL:
   Open