Re: [xsl] comparing attributes if missing at times

[Michael Kay <mike@xxxxxxxxxxxx>]

On 26 Mar 2014, at 12:41, Szabo, Patrick (LNG-VIE)
<patrick.szabo@xxxxxxxxxxxxx> wrote:
:
>
> <xsl:for-each-group select="elem" group-starting-with="elem[@x !=
preceding-sibling::elem[1]/@x]">

Like all the other comparison operators, "!=" is implicitly existential. That
is, A!=B means "some a in A, b in B satisfies a!=b".

This is handy for "=", because you can say author="Smith" and it gives a
reasonable answer if there is more than one author.

It's very rarely useful for "!=", which is why most people advise against
using it. Use not(A = B) instead,

Michael Kay
Saxonica