let X = {1,2,3,4,5,6} in

find [f:X -> X] {
    all x (f(f(x)) = x)
    AND
    all x (f(x) != x)
    AND
    find [g: X -> X] {
        f != g
        AND
        all x (g(x) != x)
        AND
        g*g = f*f
    }
}
