Re: position last and attributes

On 20/09/2012, Ihe Onwuka <ihe.onwuka@xxxxxxxxxxxxxx> wrote:
> On Thu, Sep 20, 2012 at 12:30 PM, Andrew Welch <andrew.j.welch@xxxxxxxxx>
> wrote:
>>> <A 1st="1" second="2" third="3" fourth="4" fifth="5"/>
>>>
>>> now tell me what are the first and last attributes of  A.
>>
>> Ok, but first (as hopefully this will explain it):
>>
>> 1. What is the position() of @third ?
>>
>> 2. Why do:
>>
>> @second/position()
>>
>> @third/position()
>>
>> both return 1?
>>
>
> No. I'm moving on from the orthogonal conversation to one that is
> conducted on my terms since you are the one trying to understand me.
>
>  <A 1st="1" second="2" third="3" fourth="4" fifth="5"/>
>
> 1.  what are the first and last attributes of  A.
> 2. what are A/@*[1] and A/@*[last()]
>
> Is there a definitive  answer to 1 (I say no).

Correct, because the question does not make sense: you are asking
about non-existing properties of a *set*.

> Are there definitive answers to 2 (Well a processor will always give
> you one if the set is not empty).

No - we know that this is implementation dependent.

>
> Is A/@* a representation of the attributes of A. (I say yes).

It has the same cardinality. All values of this representation are
contained in the other representation. There is a bijection between these two.

> Is A/@* a faithful representation of the attributes of A?

No: it has lost the set-ness.

>
> If A/@* is a faithful representation of the attributes of A why does
> it yields answers to questions that the original representation can't
> answer.

Because the transformation has added new properties. You might add the
colours of the rainbow, too, and it will answer questions such as
"Which is red?"

>
> So what if A/@* is not a faithful representation. Should I present the
> answers it gives me as a universal truth.

No, it's the truth about the transformation process from one to the other.

-W