(VAR x y )
(RULES 
        f(0) -> true
        f(1) -> false
        f(s(x)) -> f(x)
        if(true, s(x), s(y)) -> s(x)
        if(false, s(x), s(y)) -> s(y)
        g(x, c(y)) -> c(g(x, y))
        g(x, c(y)) -> g(x, if(f(x), c(g(s(x), y)), c(y)))
        
)