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