MAYBE

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

Strict Trs:
  { rev(a()) -> a()
  , rev(b()) -> b()
  , rev(++(x, x)) -> rev(x)
  , rev(++(x, y)) -> ++(rev(y), rev(x)) }
Obligation:
  innermost runtime complexity
Answer:
  MAYBE

The input cannot be shown compatible

Arrrr..