Re: RM and definition of relations/tuples
From: Martin Zapf <Martin_Zapf_at_gmx.net>
Date: Wed, 23 Nov 2005 23:05:16 +0100
Message-ID: <dm2p2s$l7o$1_at_online.de>
Date: Wed, 23 Nov 2005 23:05:16 +0100
Message-ID: <dm2p2s$l7o$1_at_online.de>
> On the page 32 of the Alice book I see Cartesian product definition for
> unnamed perspective, and function definition for named perspective,
> although both are informal ones. This leaves no doubt that you have
> meant
>
> t: attribute_name -> U_i dom(A_i)
>
> That is
>
> t: attribute_name -> dom(A_1) U ... U dom(A_n)
>
I exactly meant this. Received on Wed Nov 23 2005 - 23:05:16 CET