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From: Chris.Holt@newcastle.ac.uk (Chris Holt)
Newsgroups: comp.lang.prolog
Subject: Re: general data structures are impossible
Message-ID: <1991Feb19.235323.7748@newcastle.ac.uk>
Date: 19 Feb 91 23:53:23 GMT
References: <1991Feb12.013413.24312@cs.ubc.ca> <4765@goanna.cs.rmit.oz.au> <17914@cs.utexas.edu> <4789@goanna.cs.rmit.oz.au>
Sender: news@newcastle.ac.uk
Organization: University of Newcastle upon Tyne, UK, NE1 7RU
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ok@goanna.cs.rmit.oz.au (Richard A. O'Keefe) writes:
>In article <17914@cs.utexas.edu>, turpin@cs.utexas.edu (Russell Turpin) writes:
>> It takes greater mathematical sophistication to understand
>> infinite data structures.  I can explain a circular queue to
>> the average sophomore taking a Pascal class in about three
>> minutes.

>What, for example, is the task for which `cones' are an appropriate
>tool?  (I've never met them before, so this is a genuine question.
>From the brief description we've had so far, I've no idea what they
>represent or what the operations on them are.)

Not cones, exactly, but: Given a large data base, with many ways
of accessing a given piece of data (e.g. "snow" can be accessed
via "white", "crystalline", and "cold"); where updates are allowed
(since one cannot create an entire new copy of the data base with
the updated value).  There has to be an axiom that insists that
the terminus of all the access paths is always the same.  And the
usual declarative model, although fine for trees, isn't good enough
for graphs.  Does this help?
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 Chris.Holt@newcastle.ac.uk      Computing Lab, U of Newcastle upon Tyne, UK
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