(VAR x)
(RULES
c0 -> c2
c1 -> c2
f0(c0, c1) -> c3
f0(x, c2) -> f0(c2, c2)
f0(c2, x) -> f0(c2, c2)
c3 -> f0(c0, c2)
c3 -> f0(c2, c1)
)