Comment 8 for bug 1058398

Should these functions return distinct values? In thinking about it, there's no real reason why they have to. For example:

    let $s1 := (1, 2, 2, 3)
    let $s2 := (2, 3, 4)
    return seq:value-intersect( $s1, $s2 )

COULD return:

    (2, 2, 3)

which would be the same as:

    $s1[ . = $s2 ]

without using distinct-values()