MAYBE
Time: 0.010

Problem:
 Equations:
  plusAC(plusAC(x2,x3),x4) -> plusAC(x2,plusAC(x3,x4))
  plusAC(x2,x3) -> plusAC(x3,x2)
  plusAC(x2,plusAC(x3,x4)) -> plusAC(plusAC(x2,x3),x4)
  plusAC(x3,x2) -> plusAC(x2,x3)
 TRS:
  plusAC(0(),y) -> y
  plusAC(s(x),0()) -> s(x)
  plusAC(s(x),s(y)) -> s(plusAC(s(x),plusAC(y,0())))

Proof:
 Open