Re: [xsl] things about grouping

[Ihe Onwuka <ihe.onwuka@xxxxxxxxx>]

On Thu, Nov 29, 2012 at 8:18 AM, Ihe Onwuka <ihe.onwuka@xxxxxxxxx> wrote:
> On Thu, Nov 29, 2012 at 8:15 AM, Andrew Welch <andrew.j.welch@xxxxxxxxx> wrote:
>>> the comma operator corresponds to union written as | (by definition a
>>> set is unordered so the additional ordering constraint imposed by the
>>> , operator is meaningless)
>>
>> The comma is just a way of separating items in sequence, whereas union
>> de-dupes and sorts into document order.
>>
>> select="@foo, @foo, @foo"
>>
>> vs
>>
>> select="@foo | @foo | @foo"
>>
>> the former selects a sequence of 3 items, the latter a sequence of 1.
>>
>
> ok but I'm translating , into a set-theoretic construct, in which
> domain a,b is indistinct from a|b - correct me if I have got that
> wrong.

sorry you mean the deduping........

well you are no longer dealing in sets ...... so if you apply a
set-theoretic construct then all bets are off and the law of the
jungle applies.