MAYBE

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

Strict Trs:
  { acka(y(), n) -> s(n)
  , acka(a(m), y()) -> acka(m, s(0()))
  , acka(a(m), a(n)) -> acka(m, ackb(s(m), n))
  , s(n) -> a(n)
  , s(n) -> b(n)
  , 0() -> y()
  , 0() -> z()
  , ackb(z(), n) -> s(n)
  , ackb(b(m), z()) -> ackb(m, s(0()))
  , ackb(b(m), b(n)) -> acka(m, ackb(s(m), n)) }
Obligation:
  innermost runtime complexity
Answer:
  MAYBE

The input cannot be shown compatible

Arrrr..