(CONDITIONTYPE ORIENTED)
(VAR x' x'' x y' y y'')
(RULES
  f(x', x'') -> g(x) | x' == x, x'' == x
  f(y', h(y'')) -> g(y) | y' == y, y'' == y
)
(COMMENT
  \cite{TO94}, Example 2
  doi: 10.1007/3-540-60381-6_19
)