YES
Time: 0.015

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:
  zero(sharp()) -> sharp()
  plusAC(x,sharp()) -> x
  plusAC(zero(x),zero(y)) -> zero(plusAC(x,y))
  plusAC(zero(x),one(y)) -> one(plusAC(x,y))
  plusAC(one(x),one(y)) -> zero(plusAC(x,plusAC(y,one(sharp()))))

Proof:
 AC-KBO Processor:
  precedence:
   one ~ zero ~ sharp ~ plusAC
   weight function:
    w0 = 8
    w(one) = 15
    w(sharp) = 9
    w(zero) = 1
    w(plusAC) = 0
   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:
     
   Qed