TIMEOUT

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

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

Computation stopped due to timeout after 10.0 seconds.

Arrrr..