Dear Jean-Marc,

> let $idd := $elt[d]/@id

Shouldn’t it be '$d' instead of 'd' ?

  let $idd := $elt[$d]/@id

Cheers,
Christian

> return ($elt[$d]/@id,$idd)
>
> output : id="yolo".
>
> (Hence missing the second "yolo", because the correct query is : let $idd :=
> $elt[$d]/@id)
>
> However I can't figure out why the BaseX compiler ran this query ? Shouldn't
> it refused the compilation and point out this error ?
>
> Cheers,
>
> Jean-Marc
>
>
>