YES
Time: 0.011

Problem:
 Equations:
  
 TRS:
  pAC(x,zero()) -> x
  pAC(x,i(x)) -> zero()
  pAC(i(x),x) -> zero()
  a(a(x)) -> x
  b(b(x)) -> x
  a(b(a(b(a(b(x)))))) -> x

Proof:
 AC-RPO Processor:
  precedence:
   b > a > pAC > zero > i
  status:
   
  problem:
   Equations:
    
   TRS:
    
  Qed