(VAR x)
(RULES
  f(a,a) -> g(f(a,a))
  a -> b
  f(b,x) -> g(f(x,x))
  f(x,b) -> g(f(x,x))
)
(COMMENT
doi:10.1007/3-540-61064-2_39
[10] Example 8
submitted by: Takahito Aoto, Junichi Yoshida, and Yoshihito Toyama
)