Problem:
 +(0(),y) -> y
 +(s(x),y) -> s(+(x,y))
 -(0(),y) -> 0()
 -(x,0()) -> x
 -(s(x),s(y)) -> -(x,y)

Proof:
 Bounds Processor:
  bound: 1
  enrichment: match
  automaton:
   final states: {4,3}
   transitions:
    -1(1,2) -> 4*
    -1(2,1) -> 4*
    -1(1,1) -> 4*
    -1(2,2) -> 4*
    01() -> 4*
    s1(6) -> 6,3
    +1(1,2) -> 6*
    +1(2,1) -> 6*
    +1(1,1) -> 6*
    +1(2,2) -> 6*
    +0(1,2) -> 3*
    +0(2,1) -> 3*
    +0(1,1) -> 3*
    +0(2,2) -> 3*
    00() -> 1*
    s0(2) -> 2*
    s0(1) -> 2*
    -0(1,2) -> 4*
    -0(2,1) -> 4*
    -0(1,1) -> 4*
    -0(2,2) -> 4*
    1 -> 6,4,3
    2 -> 6,4,3
  problem:
   
  Qed