MAYBE
Time: 0.004200
TRS:
 {  -(x, 0()) -> x,
  -(s x, s y) -> -(x, y),
    +(0(), y) -> y,
    +(s x, y) -> s +(x, y),
    *(x, 0()) -> 0(),
    *(x, s y) -> +(x, *(x, y)),
    f(s x, y) -> f(-(*(s x, s y), s *(s x, y)), *(y, y))}
 DP:
  DP:
   {-#(s x, s y) -> -#(x, y),
      +#(s x, y) -> +#(x, y),
      *#(x, s y) -> +#(x, *(x, y)),
      *#(x, s y) -> *#(x, y),
      f#(s x, y) -> -#(*(s x, s y), s *(s x, y)),
      f#(s x, y) -> *#(y, y),
      f#(s x, y) -> *#(s x, y),
      f#(s x, y) -> *#(s x, s y),
      f#(s x, y) -> f#(-(*(s x, s y), s *(s x, y)), *(y, y))}
  TRS:
  {  -(x, 0()) -> x,
   -(s x, s y) -> -(x, y),
     +(0(), y) -> y,
     +(s x, y) -> s +(x, y),
     *(x, 0()) -> 0(),
     *(x, s y) -> +(x, *(x, y)),
     f(s x, y) -> f(-(*(s x, s y), s *(s x, y)), *(y, y))}
  EDG:
   {(-#(s x, s y) -> -#(x, y), -#(s x, s y) -> -#(x, y))
    (*#(x, s y) -> *#(x, y), *#(x, s y) -> *#(x, y))
    (*#(x, s y) -> *#(x, y), *#(x, s y) -> +#(x, *(x, y)))
    (f#(s x, y) -> -#(*(s x, s y), s *(s x, y)), -#(s x, s y) -> -#(x, y))
    (f#(s x, y) -> f#(-(*(s x, s y), s *(s x, y)), *(y, y)), f#(s x, y) -> f#(-(*(s x, s y), s *(s x, y)), *(y, y)))
    (f#(s x, y) -> f#(-(*(s x, s y), s *(s x, y)), *(y, y)), f#(s x, y) -> *#(s x, s y))
    (f#(s x, y) -> f#(-(*(s x, s y), s *(s x, y)), *(y, y)), f#(s x, y) -> *#(s x, y))
    (f#(s x, y) -> f#(-(*(s x, s y), s *(s x, y)), *(y, y)), f#(s x, y) -> *#(y, y))
    (f#(s x, y) -> f#(-(*(s x, s y), s *(s x, y)), *(y, y)), f#(s x, y) -> -#(*(s x, s y), s *(s x, y)))
    (f#(s x, y) -> *#(s x, s y), *#(x, s y) -> +#(x, *(x, y)))
    (f#(s x, y) -> *#(s x, s y), *#(x, s y) -> *#(x, y))
    (*#(x, s y) -> +#(x, *(x, y)), +#(s x, y) -> +#(x, y))
    (f#(s x, y) -> *#(y, y), *#(x, s y) -> +#(x, *(x, y)))
    (f#(s x, y) -> *#(y, y), *#(x, s y) -> *#(x, y))
    (+#(s x, y) -> +#(x, y), +#(s x, y) -> +#(x, y))
    (f#(s x, y) -> *#(s x, y), *#(x, s y) -> +#(x, *(x, y)))
    (f#(s x, y) -> *#(s x, y), *#(x, s y) -> *#(x, y))}
   STATUS:
    arrows: 0.790123
    SCCS (4):
     Scc:
      {f#(s x, y) -> f#(-(*(s x, s y), s *(s x, y)), *(y, y))}
     Scc:
      {-#(s x, s y) -> -#(x, y)}
     Scc:
      {*#(x, s y) -> *#(x, y)}
     Scc:
      {+#(s x, y) -> +#(x, y)}
     
     SCC (1):
      Strict:
       {f#(s x, y) -> f#(-(*(s x, s y), s *(s x, y)), *(y, y))}
      Weak:
      {  -(x, 0()) -> x,
       -(s x, s y) -> -(x, y),
         +(0(), y) -> y,
         +(s x, y) -> s +(x, y),
         *(x, 0()) -> 0(),
         *(x, s y) -> +(x, *(x, y)),
         f(s x, y) -> f(-(*(s x, s y), s *(s x, y)), *(y, y))}
      Open
     
     
     
     SCC (1):
      Strict:
       {-#(s x, s y) -> -#(x, y)}
      Weak:
      {  -(x, 0()) -> x,
       -(s x, s y) -> -(x, y),
         +(0(), y) -> y,
         +(s x, y) -> s +(x, y),
         *(x, 0()) -> 0(),
         *(x, s y) -> +(x, *(x, y)),
         f(s x, y) -> f(-(*(s x, s y), s *(s x, y)), *(y, y))}
      Open
     
     SCC (1):
      Strict:
       {*#(x, s y) -> *#(x, y)}
      Weak:
      {  -(x, 0()) -> x,
       -(s x, s y) -> -(x, y),
         +(0(), y) -> y,
         +(s x, y) -> s +(x, y),
         *(x, 0()) -> 0(),
         *(x, s y) -> +(x, *(x, y)),
         f(s x, y) -> f(-(*(s x, s y), s *(s x, y)), *(y, y))}
      Open
     
     SCC (1):
      Strict:
       {+#(s x, y) -> +#(x, y)}
      Weak:
      {  -(x, 0()) -> x,
       -(s x, s y) -> -(x, y),
         +(0(), y) -> y,
         +(s x, y) -> s +(x, y),
         *(x, 0()) -> 0(),
         *(x, s y) -> +(x, *(x, y)),
         f(s x, y) -> f(-(*(s x, s y), s *(s x, y)), *(y, y))}
      Open