MAYBE
Time: 0.011

Problem:
 Equations:
  pAC(pAC(x1,x2),x3) -> pAC(x1,pAC(x2,x3))
  pAC(x1,x2) -> pAC(x2,x1)
  pAC(x1,pAC(x2,x3)) -> pAC(pAC(x1,x2),x3)
  pAC(x2,x1) -> pAC(x1,x2)
 TRS:
  pAC(a(),x) -> pAC(b(),g(a()))

Proof:
 Open