(VAR x y)
(RULES
  s(p(x)) -> x
  p(s(x)) -> x
  m(x,0) -> x
  m(x, s(y)) -> p(m(x,y))
  m(x,p(y)) -> s(m(x,y))
  m(p(x), y) -> p(m(x,y))
  m(s(x), y) -> s(m(x, y))
  a(x, 0) -> x
  a(0, x) -> x
  a(x, s(y)) -> s(a(x,y))
  a(x, p(y)) -> p(a(x,y))
  a(s(x), y) -> s(a(x,y))
  a(p(x), y) -> p(a(x,y))
)