Problem:
 +(0(),x) -> x
 +(x,0()) -> x
 +(1(),-(1())) -> 0()
 +(-(1()),1()) -> 0()
 -(0()) -> 0()
 -(-(x)) -> x
 -(+(x,y)) -> +(-(x),-(y))
 +(+(x,y),z) -> +(x,+(y,z))
 +(x,y) -> +(y,x)

Proof:
 Church Rosser Transformation Processor (ac):
  f5_AC(0(),x) -> x
  f5_AC(x,0()) -> x
  f5_AC(1(),-(1())) -> 0()
  f5_AC(-(1()),1()) -> 0()
  -(0()) -> 0()
  -(-(x)) -> x
  -(f5_AC(x,y)) -> f5_AC(-(x),-(y))
  AC critical peaks: joinable
  AC-KBO Processor:
   precedence:
    - > f5_AC > 1 > 0
    weight function:
     w0 = 1
     w(0) = 7
     w(f5_AC) = 5
     w(1) = 1
     w(-) = 0
    problem:
     
    Qed