MAYBE

Problem:
 -(x,0()) -> x
 -(s(x),s(y)) -> -(x,y)
 p(s(x)) -> x
 f(s(x),y) -> f(p(-(s(x),y)),p(-(y,s(x))))
 f(x,s(y)) -> f(p(-(x,s(y))),p(-(s(y),x)))

Proof:
 DP Processor:
  DPs:
   -#(s(x),s(y)) -> -#(x,y)
   f#(s(x),y) -> -#(y,s(x))
   f#(s(x),y) -> p#(-(y,s(x)))
   f#(s(x),y) -> -#(s(x),y)
   f#(s(x),y) -> p#(-(s(x),y))
   f#(s(x),y) -> f#(p(-(s(x),y)),p(-(y,s(x))))
   f#(x,s(y)) -> -#(s(y),x)
   f#(x,s(y)) -> p#(-(s(y),x))
   f#(x,s(y)) -> -#(x,s(y))
   f#(x,s(y)) -> p#(-(x,s(y)))
   f#(x,s(y)) -> f#(p(-(x,s(y))),p(-(s(y),x)))
  TRS:
   -(x,0()) -> x
   -(s(x),s(y)) -> -(x,y)
   p(s(x)) -> x
   f(s(x),y) -> f(p(-(s(x),y)),p(-(y,s(x))))
   f(x,s(y)) -> f(p(-(x,s(y))),p(-(s(y),x)))
  Usable Rule Processor:
   DPs:
    -#(s(x),s(y)) -> -#(x,y)
    f#(s(x),y) -> -#(y,s(x))
    f#(s(x),y) -> p#(-(y,s(x)))
    f#(s(x),y) -> -#(s(x),y)
    f#(s(x),y) -> p#(-(s(x),y))
    f#(s(x),y) -> f#(p(-(s(x),y)),p(-(y,s(x))))
    f#(x,s(y)) -> -#(s(y),x)
    f#(x,s(y)) -> p#(-(s(y),x))
    f#(x,s(y)) -> -#(x,s(y))
    f#(x,s(y)) -> p#(-(x,s(y)))
    f#(x,s(y)) -> f#(p(-(x,s(y))),p(-(s(y),x)))
   TRS:
    f8(x,y) -> x
    f8(x,y) -> y
    -(s(x),s(y)) -> -(x,y)
    -(x,0()) -> x
    p(s(x)) -> x
   CDG Processor:
    DPs:
     -#(s(x),s(y)) -> -#(x,y)
     f#(s(x),y) -> -#(y,s(x))
     f#(s(x),y) -> p#(-(y,s(x)))
     f#(s(x),y) -> -#(s(x),y)
     f#(s(x),y) -> p#(-(s(x),y))
     f#(s(x),y) -> f#(p(-(s(x),y)),p(-(y,s(x))))
     f#(x,s(y)) -> -#(s(y),x)
     f#(x,s(y)) -> p#(-(s(y),x))
     f#(x,s(y)) -> -#(x,s(y))
     f#(x,s(y)) -> p#(-(x,s(y)))
     f#(x,s(y)) -> f#(p(-(x,s(y))),p(-(s(y),x)))
    TRS:
     f8(x,y) -> x
     f8(x,y) -> y
     -(s(x),s(y)) -> -(x,y)
     -(x,0()) -> x
     p(s(x)) -> x
    graph:
     f#(s(x),y) -> f#(p(-(s(x),y)),p(-(y,s(x)))) ->
     f#(s(x),y) -> -#(y,s(x))
     f#(s(x),y) -> f#(p(-(s(x),y)),p(-(y,s(x)))) ->
     f#(s(x),y) -> p#(-(y,s(x)))
     f#(s(x),y) -> f#(p(-(s(x),y)),p(-(y,s(x)))) ->
     f#(s(x),y) -> -#(s(x),y)
     f#(s(x),y) -> f#(p(-(s(x),y)),p(-(y,s(x)))) ->
     f#(s(x),y) -> p#(-(s(x),y))
     f#(s(x),y) -> f#(p(-(s(x),y)),p(-(y,s(x)))) ->
     f#(s(x),y) -> f#(p(-(s(x),y)),p(-(y,s(x))))
     f#(s(x),y) -> f#(p(-(s(x),y)),p(-(y,s(x)))) ->
     f#(x,s(y)) -> -#(s(y),x)
     f#(s(x),y) -> f#(p(-(s(x),y)),p(-(y,s(x)))) ->
     f#(x,s(y)) -> p#(-(s(y),x))
     f#(s(x),y) -> f#(p(-(s(x),y)),p(-(y,s(x)))) ->
     f#(x,s(y)) -> -#(x,s(y))
     f#(s(x),y) -> f#(p(-(s(x),y)),p(-(y,s(x)))) ->
     f#(x,s(y)) -> p#(-(x,s(y)))
     f#(s(x),y) -> f#(p(-(s(x),y)),p(-(y,s(x)))) ->
     f#(x,s(y)) -> f#(p(-(x,s(y))),p(-(s(y),x)))
     f#(s(x),y) -> -#(s(x),y) -> -#(s(x),s(y)) -> -#(x,y)
     f#(s(x),y) -> -#(y,s(x)) ->
     -#(s(x),s(y)) -> -#(x,y)
     f#(x,s(y)) -> f#(p(-(x,s(y))),p(-(s(y),x))) ->
     f#(s(x),y) -> -#(y,s(x))
     f#(x,s(y)) -> f#(p(-(x,s(y))),p(-(s(y),x))) ->
     f#(s(x),y) -> p#(-(y,s(x)))
     f#(x,s(y)) -> f#(p(-(x,s(y))),p(-(s(y),x))) ->
     f#(s(x),y) -> -#(s(x),y)
     f#(x,s(y)) -> f#(p(-(x,s(y))),p(-(s(y),x))) ->
     f#(s(x),y) -> p#(-(s(x),y))
     f#(x,s(y)) -> f#(p(-(x,s(y))),p(-(s(y),x))) ->
     f#(s(x),y) -> f#(p(-(s(x),y)),p(-(y,s(x))))
     f#(x,s(y)) -> f#(p(-(x,s(y))),p(-(s(y),x))) ->
     f#(x,s(y)) -> -#(s(y),x)
     f#(x,s(y)) -> f#(p(-(x,s(y))),p(-(s(y),x))) ->
     f#(x,s(y)) -> p#(-(s(y),x))
     f#(x,s(y)) -> f#(p(-(x,s(y))),p(-(s(y),x))) ->
     f#(x,s(y)) -> -#(x,s(y))
     f#(x,s(y)) -> f#(p(-(x,s(y))),p(-(s(y),x))) ->
     f#(x,s(y)) -> p#(-(x,s(y)))
     f#(x,s(y)) -> f#(p(-(x,s(y))),p(-(s(y),x))) ->
     f#(x,s(y)) -> f#(p(-(x,s(y))),p(-(s(y),x)))
     f#(x,s(y)) -> -#(s(y),x) -> -#(s(x),s(y)) -> -#(x,y)
     f#(x,s(y)) -> -#(x,s(y)) -> -#(s(x),s(y)) -> -#(x,y)
     -#(s(x),s(y)) -> -#(x,y) -> -#(s(x),s(y)) -> -#(x,y)
    Restore Modifier:
     DPs:
      -#(s(x),s(y)) -> -#(x,y)
      f#(s(x),y) -> -#(y,s(x))
      f#(s(x),y) -> p#(-(y,s(x)))
      f#(s(x),y) -> -#(s(x),y)
      f#(s(x),y) -> p#(-(s(x),y))
      f#(s(x),y) -> f#(p(-(s(x),y)),p(-(y,s(x))))
      f#(x,s(y)) -> -#(s(y),x)
      f#(x,s(y)) -> p#(-(s(y),x))
      f#(x,s(y)) -> -#(x,s(y))
      f#(x,s(y)) -> p#(-(x,s(y)))
      f#(x,s(y)) -> f#(p(-(x,s(y))),p(-(s(y),x)))
     TRS:
      -(x,0()) -> x
      -(s(x),s(y)) -> -(x,y)
      p(s(x)) -> x
      f(s(x),y) -> f(p(-(s(x),y)),p(-(y,s(x))))
      f(x,s(y)) -> f(p(-(x,s(y))),p(-(s(y),x)))
     SCC Processor:
      #sccs: 2
      #rules: 3
      #arcs: 25/121
      DPs:
       f#(s(x),y) -> f#(p(-(s(x),y)),p(-(y,s(x))))
       f#(x,s(y)) -> f#(p(-(x,s(y))),p(-(s(y),x)))
      TRS:
       -(x,0()) -> x
       -(s(x),s(y)) -> -(x,y)
       p(s(x)) -> x
       f(s(x),y) -> f(p(-(s(x),y)),p(-(y,s(x))))
       f(x,s(y)) -> f(p(-(x,s(y))),p(-(s(y),x)))
      Open
      
      DPs:
       -#(s(x),s(y)) -> -#(x,y)
      TRS:
       -(x,0()) -> x
       -(s(x),s(y)) -> -(x,y)
       p(s(x)) -> x
       f(s(x),y) -> f(p(-(s(x),y)),p(-(y,s(x))))
       f(x,s(y)) -> f(p(-(x,s(y))),p(-(s(y),x)))
      Open