(VAR x y u v)
(RULES
f(true, x, y) -> f(gt(x, y), x, round(s(y)))
round(0) -> 0
round(s(0)) -> s(s(0))
round(s(s(x))) -> s(s(round(x)))
gt(0, v) -> false
gt(s(u), 0) -> true
gt(s(u), s(v)) -> gt(u, v)
)