Re: Yet another relational programming language

From: paul c <>
Date: Thu, 10 Sep 2009 22:53:29 GMT
Message-ID: <Jrfqm.44477$PH1.1801_at_edtnps82>

Vadim Tropashko wrote:

Vadim, just curious about a perhaps not very common case:

supposing attributes c and s are constrained to the values {1,2} and these predicates:

"c is a customer":

"s is a supplier"


In an unconstrained version of D&D algebra,

"c is a custome OR s is a supplier":

C <OR> S:
c s
1 1
1 2
2 2

In rellattice I presume the result of C v S would be something like
"table_dee", is that right?

If so, can one use negation in rellatice to get the same result or is there another way?

Received on Thu Sep 10 2009 - 17:53:29 CDT

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