MAYBE

'Pop* (timeout of 60.0 seconds)'
--------------------------------
Answer:           MAYBE
Input Problem:    innermost runtime-complexity with respect to
  Rules:
    {  a(x1) -> b(x1)
     , a(b(b(x1))) -> c(x1)
     , a(c(x1)) -> c(b(a(a(x1))))}

Proof Output:    
  The input cannot be shown compatible