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Re: Fraud Number 3: U-Gene

From: Cimode <cimode_at_hotmail.com>
Date: 20 Jun 2006 06:33:56 -0700
Message-ID: <1150810436.032464.218080@b68g2000cwa.googlegroups.com>

Tony D wrote:
> Cimode wrote:
> > > But I'm not sure how you could confuse an attribute with a relvar.
> > As I stated B4 if their definition are too similar to be clearly
> > distinguished..It's an open highway for unexperienced audiences to
> > confuse both. This is the last explanation I will give on that
> > point...I have already answered above and I will stop reexplaining....
> >
>
> But a variable is time varying; an attribute is, for want of a better
> word, an attribute of a relation *value*, so it can't change. I simply
> don't see how this confusion can come about.
In the perspective of any definition of what a function is, it is not the variable that is time varying but the "variable filler".

Try to imagine a bus at different point during the day circuit and people that get up in the bus in each station.

Now consider the bus as a variable and the people as value. (variable placeholders)...What is time varying? the bus? or the set of people that get in the bus?

The fact that the set of people are drawn from the *citizen* domain and are unique is a different concept. it is the concept of *uniqueness* you are confusing with the concept of variability...

> > *change* is a verb that leads to confusion in defining the relationship
> > between variables and values. *change* supposes a modification of
> > state which. I prefer the definition of variable as a *value holder*
> > which give a much more clearer indication .
> >
>
> I don't see that. Values never change. Which value is indicated by a
> variable can.

Neither values, variable or function change. I told you this term is confusing but you choose to ignore my warning. Could you stop using that term..Use "vary" instead

> > You are confusing domain and type...
> I'm not confusing them; I'm saying that I don't see a need for the
> separation between them that you're describing. Can you say why you
> would separate them in such a way ?

Because you must define at some point in time what makes a difference between *possible* values and *permissible* values...*possible* values are domain values. *permissible* values is a definition of restrictions should be applied in extraction of possible values from a specific domain. For instance, if you consider an domain representing all integer and consider the following relation

odd_numbers(odd_number datatype1)....If you do not make a difference between datatype1 (data type) and the domain of integer (domain) , how do you actually implement integrity verification in values stored? odd_number must only contain odd numbers not all integers..Right?

I am sorry but I can not make more explicit example and analogy...You really need to get further in RM education. Received on Tue Jun 20 2006 - 08:33:56 CDT

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