(RULES
  a -> a
  a -> g(a)
  a -> f(f(a, a), a)
  f(g(a), f(a, a)) -> f(g(a), f(a, a))
)
(COMMENT -f "a:0 g:1 f:2" -r 4 -v 0 -d 2 -s 6 "NFP & ~CR")