MAYBE

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

Proof Output:    
  The input cannot be shown compatible