YES
Time: 0.015

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-KBO Processor:
  precedence:
   pAC > zero > b > i > a
   weight function:
    w0 = 1
    w(b) = 15
    w(zero) = 6
    w(i) = 4
    w(a) = 3
    w(pAC) = 0
   problem:
    Equations:
     
    TRS:
     
   Qed