Unfortunately this does not work because, if the second sequence has only one 3 (and the first has two 3), I will still get two 3, while I should get only one.

>
> Or more FLOWR like
> for $a in (1,2,3,5,3)
> where $a . = (1,3,2)
> group by $o := $a
> return
> <c>{$a}</c>






> On 25. Nov 2020, at 09:11, Martin Honnen <martin.honnen@gmx.de> wrote:
>
> Am 25.11.2020 um 08:39 schrieb Martin Honnen:
>> Am 25.11.2020 um 06:37 schrieb Giuseppe G. A. Celano:
>>
>>> I have to compare two sequences and find common items, irrespective of
>>> their positions:
>>>
>>> for $a in (1,2,3,5,3)
>>> for $u in (1,3,2,3)
>>> where $a = $u
>>> group by $o := $a
>>> return
>>> <c>{$a}</c>
>>>
>>> This returns
>>> <c>1</c>
>>> <c>2</c>
>>> <c>3 3 3 3</c>
>>>
>>> I would like 3 to be repeated only twice (i.e., each item in the first
>>> sequence should pair only with one in the second sentence): is there an
>>> XQuery "trick" for that in the FLOWR expression?
>>
>> I think
>>
>> for $a in (1,2,3,5,3)[. = (1,3,2,3)]
>> group by $o := $a
>> return
>> <c>{$a}</c>
>>
>> would do that
>
> Or more FLOWR like
> for $a in (1,2,3,5,3)
> where $a . = (1,3,2,3)
> group by $o := $a
> return
> <c>{$a}</c>
>