Re: compound propositions
From: paul c <toledobythesea_at_oohay.ac>
Date: Mon, 15 Mar 2010 22:20:59 GMT
Message-ID: <fpynn.68195$Db2.35162_at_edtnps83>
Date: Mon, 15 Mar 2010 22:20:59 GMT
Message-ID: <fpynn.68195$Db2.35162_at_edtnps83>
Bob Badour wrote:
> paul c wrote:
>> Bob Badour wrote:
...
>> not knowing its purpose any more than a dbms designer can predict the
>> exact purpose some unknown db is used for, other than to say
>> intersection and quantification are involved. If you mean 'internal',
>> that which an algebra operates with, it is basically the expression
>> 'Customer[id] join Client[id]', standing for the intersection of the
>> set of Customer id's that match Client id's and vice-versa.
> > Actually, for join it is "'id' is a customer and a client". For union, > it would be "'id' is a customer or a client". > ...
Am pondering the significance of the other comments. Received on Mon Mar 15 2010 - 23:20:59 CET