MAYBE We are left with following problem, upon which TcT provides the certificate MAYBE. Strict Trs: { ge(x, 0()) -> true() , ge(0(), s(y)) -> false() , ge(s(x), s(y)) -> ge(x, y) , minus(x, 0()) -> x , minus(0(), y) -> 0() , minus(s(x), s(y)) -> minus(x, y) , id_inc(x) -> x , id_inc(x) -> s(x) , div(x, y) -> if(ge(y, s(0())), ge(x, y), x, y) , if(true(), true(), x, y) -> id_inc(div(minus(x, y), y)) , if(true(), false(), x, y) -> 0() , if(false(), b, x, y) -> div_by_zero() } Obligation: innermost runtime complexity Answer: MAYBE The input cannot be shown compatible Arrrr..