MAYBE
Trs:
 {    s(p(x)) -> x,
      p(s(x)) -> x,
   minus(0()) -> 0(),
  minus(s(x)) -> p(minus(x)),
  minus(p(x)) -> s(minus(x)),
    *(0(), y) -> 0(),
   *(s(x), y) -> +(*(x, y), y),
   *(p(x), y) -> +(*(x, y), minus(y)),
    +(0(), y) -> y,
   +(s(x), y) -> s(+(x, y)),
   +(p(x), y) -> p(+(x, y))}
 Comment:
  We consider a duplicating trs.
  FAIL:
   Open