Re: boolean datatype ... wtf?

On 29 sep, 15:46, paul c <toledobythe..._at_oohay.ac> wrote:
> On 29/09/2010 4:51 AM, Paul Mansour wrote:
> ...
>
>
>
> > What is the problem with a Boolean data type?
> > .
> > It is fundamental - so fundamental  that in TTM it is the only
> > required scalar data type:  “We require that at least one built-in
> > scalar type be supported : Namely, type “Boolean” (BOOLEAN in Tutorial
> > D”).
>
> > Date and Darwen go on to give the obvious reasons for this.
>
> > The fact that DEE and DUM may be interpreted as TRUE and FALSE is not
> > relevant.  The result of A=B or A>B is not a relation.
>
> Aren't A=B and A>B relations?

Here we go again ...

But then again, incidentally, he did not say that 'A=B' isn't a relation. He said that _THE RESULT OF_ 'A=B' isn't a relation.

Conceptually, it could be argued that what a language implementation achieves when it evaluates an expression such as 'A=B', is to join a tuple {A,B} with the EQUALS relation (which is implicitly defined by the system) of the pertinent type, and then check whether the result of that join is empty or not ...

Fair bit of hairsplitting going on, if you ask me ... Received on Wed Sep 29 2010 - 16:07:21 CEST