MAYBE

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

Strict Trs:
  { plus(0(), x) -> x
  , plus(s(x), y) -> s(plus(p(s(x)), y))
  , p(s(0())) -> 0()
  , p(s(s(x))) -> s(p(s(x)))
  , times(0(), y) -> 0()
  , times(s(x), y) -> plus(y, times(p(s(x)), y))
  , fac(0(), x) -> x
  , fac(s(x), y) -> fac(p(s(x)), times(s(x), y))
  , factorial(x) -> fac(x, s(0())) }
Obligation:
  innermost runtime complexity
Answer:
  MAYBE

The input cannot be shown compatible

Arrrr..