Returns all but the first item in a sequence.
fn:tail( $arg as item()*item()*The function returns the value of the expression subsequence($arg, 2)
The expression fn:tail(1 to 5) returns (2, 3, 4, 5).
The expression fn:tail(("a", "b", "c")) returns ("b", "c").
The expression fn:tail("a") returns ().
The expression fn:tail(()) returns ().
The expression fn:tail([1,2,3]) returns ().
If $arg is the empty sequence, or a sequence containing a single item, then
the empty sequence is returned.
