> On 24 Feb 2018, at 00:18, G. Ken Holman g.ken.holman@xxxxxxxxx
<xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx> wrote:
>
> Ignore that second expression ... I wrote it too hastily and I'm now back at
my desk to think about it.
>
> This would work I think:
>
>  <xsl:value-of select="some $this in .//* satisfies
>                        some $that in $elements-to-keep
>                        satisfies $this is $that"/>
>

I think that's equivalent to saying that the intersection of the two sets is
non empty:

select="exists(.//* intersect $elements-to-keep)"

Michael Kay
Saxonica