Re: RM formalism supporting partial information

From: David Cressey <>
Date: Sun, 18 Nov 2007 14:28:36 GMT
Message-ID: <o_X%i.2690$Jy1.596_at_trndny02>

"Jan Hidders" <> wrote in message

> PS. Note that I am oversimplifying because I left out the headers,
> which need to be taken into account to get a completely correct
> definition of "information content" in this setting. The relation with
> header {a,b} and body {(a=1, b=null)} does not necessarily have the
> same information content as the one with header {a} and body {(a=1)}.
> But considering that (1) it is not hard to see how to add that and (2)
> it would make the definitions more complex without really adding to
> the essential insight, I left them out anyway.


I am sure you are right about this. What's not clear to me is whether the difference in "information content" between the two cases you give is relevant to the information content in the context of the subject matter, or whether it's a difference in information content that's relevant only in the context of the implementation we are looking at.

I suspect that this quandary is exactly what's responsible for so much misinterpretation of NULLs in the world of application programming. Received on Sun Nov 18 2007 - 15:28:36 CET

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