Re: deductive databases

From: Jan Hidders <jan.hidders_at_REMOVETHIS.pandora.be>
Date: Fri, 20 May 2005 18:49:32 GMT
Message-ID: <0jqje.96619$Rk1.5615685@phobos.telenet-ops.be>

Torkel Franzen wrote:
> Jan Hidders <jan.hidders_at_REMOVETHIS.pandora.be> writes:
>

>>"There exists a formula over two binary predicates R and S that is true 
>>iff S is the transitive closure of R."

>
> True in what structure?

In a structure with the two binary relations R and S. The formula should be true for precisely those structures in which S is the transitive closure of R.

Jan Hidders

Received on Fri May 20 2005 - 13:49:32 CDT