MAYBE
Time: 0.055

Problem:
 Equations:
  pAC(pAC(x3,x4),x5) -> pAC(x3,pAC(x4,x5))
  pAC(x3,x4) -> pAC(x4,x3)
  pAC(x3,pAC(x4,x5)) -> pAC(pAC(x3,x4),x5)
  pAC(x4,x3) -> pAC(x3,x4)
 TRS:
  pAC(x,zero()) -> x
  pAC(i(x),x) -> zero()
  m(one(),x) -> x
  m(x,one()) -> x
  m(x,m(y,z)) -> m(m(x,y),z)
  m(z,pAC(x,y)) -> pAC(m(z,x),m(z,y))
  m(pAC(x,y),z) -> pAC(m(x,z),m(y,z))

Proof:
 Open