MAYBE

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

Strict Trs:
  { a__f(X1, X2, X3) -> f(X1, X2, X3)
  , a__f(a(), X, X) -> a__f(X, a__b(), b())
  , a__b() -> a()
  , a__b() -> b()
  , mark(a()) -> a()
  , mark(b()) -> a__b()
  , mark(f(X1, X2, X3)) -> a__f(X1, mark(X2), X3) }
Obligation:
  innermost runtime complexity
Answer:
  MAYBE

The input cannot be shown compatible

Arrrr..