Re: Another attempt...

On 21/03/2008, Arjohn Kampman <arjohn.kampman@aduna-software.com> wrote:
>   > U - universal relation - a relation with no attributes but contains
>   > all possible tuples of applicable type.
>
>  > 0 - empty relation - the empty relation (no attributes no tuples).
>
>
> These are the definitions of DEE and DUM, not U and 0.
>

These definitions are paraphrasing the definitions on page 259.  I did
not intend to mislead.

The full definitions are:
Let U be the universal relation of type T - i.e., the relation contain
all possible tuples of the applicable tuple type.
Let 0 be the empty relation of type T.

Received on Sunday, 23 March 2008 13:21:55 UTC