MAYBE

We are left with following problem, upon which TcT provides the
certificate MAYBE.

Strict Trs:
  { leq(0(), y) -> true()
  , leq(s(x), 0()) -> false()
  , leq(s(x), s(y)) -> leq(x, y)
  , if(true(), x, y) -> x
  , if(false(), x, y) -> y
  , -(x, 0()) -> x
  , -(s(x), s(y)) -> -(x, y)
  , mod(0(), y) -> 0()
  , mod(s(x), 0()) -> 0()
  , mod(s(x), s(y)) ->
    if(leq(y, x), mod(-(s(x), s(y)), s(y)), s(x)) }
Obligation:
  innermost runtime complexity
Answer:
  MAYBE

The input cannot be shown compatible

Arrrr..