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Re: why hierarchy?

From: Neo <neo55592_at_hotmail.com>
Date: 31 Jul 2006 14:47:58 -0700
Message-ID: <1154382478.788949.200950@75g2000cwc.googlegroups.com>


>>> how you would represent something like "A person called Bob is friends with a person called Tom" in your system (obviously that's a bidirectional relationship).
>>
>> (new 'bob 'person)
>> (new 'tom 'person)
>> (new 'friend 'verb)
>> (create bob friend tom)
>> (create tom friend bob)
>
> A better question would be to ask if the requirements change and one
> needs to record when the friendship began, how does dbd record the bob
> and tom have been friends since October 12, 1993 ?

(new 'since)
(new '10/12/1993 'date)
(create bob friend tom since 10/12/1993)
(create tom friend bob since 10/12/1993)

Note: date modelled in simplified manner. Also since could instead be begin, start, etc. Received on Mon Jul 31 2006 - 16:47:58 CDT

Original text of this message

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