YES
Time: 0.118

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

Proof:
 AC-KBO Processor:
  precedence:
   i > pAC > b ~ a ~ zero
   weight function:
    w0 = 2
    w(b) = 11
    w(a) = 9
    w(zero) = 4
    w(i) = w(pAC) = 0
   problem:
    Equations:
     
    TRS:
     
   Qed