"Pruning" an xml "tree" based on nodes' ids

[Martin Probst]

> copy $x := ...
> transform (
>  delete nodes $x//branch[ID != (4, 8)], $x//leaf[ID != 15]
> )
> return $x

Whoops, that should have been

copy $x := ...
transform (
 delete nodes ($x//branch[every $x in (4, 8) satisfies ID != $x],
$x//leaf[ID != 15])
)
return $x

If you compare using != against a list, you need to use
every/satisfies, otherwise the expression will be true if only one of
the values is not equal to the list. Also, parentheses around the
delete nodes part are needed.

Martin