(VAR u x y z )
(RULES 
        inc(s(x)) -> s(inc(x))
        inc(0) -> s(0)
        plus(x, y) -> ifPlus(eq(x, 0), minus(x, s(0)), x, inc(x))
        ifPlus(false, x, y, z) -> plus(x, z)
        ifPlus(true, x, y, z) -> y
        minus(s(x), s(y)) -> minus(x, y)
        minus(0, x) -> 0
        minus(x, 0) -> x
        minus(x, x) -> 0
        eq(s(x), s(y)) -> eq(x, y)
        eq(0, s(x)) -> false
        eq(s(x), 0) -> false
        eq(0, 0) -> true
        eq(x, x) -> true
        times(x, y) -> timesIter(x, y, 0)
        timesIter(x, y, z) -> ifTimes(eq(x, 0), minus(x, s(0)), y, z, plus(y, z))
        ifTimes(true, x, y, z, u) -> z
        ifTimes(false, x, y, z, u) -> timesIter(x, y, u)
        f -> g
        f -> h
        
)