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Re: Generic or specific

From: Mark Preston <mark_at_mpreston.demon.co.uk>
Date: 2000/04/13
Message-ID: <38f49205.1074818@news.demon.co.uk>#1/1

On Tue, 11 Apr 2000 16:51:50 +0300, gkiourtas michail <michgkio_at_otenet.gr> wrote:

>For a lending library project:
>a) Is book and a copy of this book an unary relationship?
How many copies of a book can there be? More than one, of course, and so the relationship cannot be unary.
>b) Is book a generic entity and a copy of it a specific entity?
'Books' is a generic entity and each book a specific example of such an entity.

-- 
Mark A Preston BSc, FIAP
The Magpie's Nest
mark_at_mpreston.demon.co.uk
Received on Thu Apr 13 2000 - 00:00:00 CDT

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