Re: 1GB Tables as Classes, or Tables as Types, and all that refuted

On Thu, 25 Nov 2004 21:25:51 +0100, "Rene de Visser" <Rene_de_Visser_at_hotmail.com> wrote:

>> The problem is how to describe such relation value and how to define
>> the operators of the type.
>
>The relation value is often described algebraically using a modal logic
>extended with quanfiers and relations.

Interesting.

>(Relations are of two basic types in AP5, defined or stored).
>In AP5 operaters are also relations.
>See my other posting for how a plus operator can be defined relationally.

Also interesting.

>values of a type <=> 1-ary relation value
>type <=> relation / relation definition / relation name

and operators.

IMHO when we are defining the set of values of a type in a statement like this:

type Lenght possrep { Integer constraint Lenght > 0 };

This is a domain definition and not a complete type definition because we still have not defined the operators.

>in AP5 relations are second class objects. i.e. there is a 1-1 relationship
>between relation / relation defintion and relation name.

Ok, but that relationship does not mean that the three things are the same thing.

Regards Received on Wed Dec 01 2004 - 17:01:48 CET