start :: fn {
    a := (1,2)
    a[0] <=> 1
    a[1] <=> 2

    b := (1,)
    b[0] <=> 1

    empty := ()
    c := (empty,)
    c[0] <=> ()

    d := (1,2)
    d[0] <=> d[0]

    {
        q := d[0]
        w := d[0]
        q + w
        q - w
        q * w
    }
}