Re: Types and "join compatibility"
From: Marshall Spight <marshall.spight_at_gmail.com>
Date: 30 Jul 2005 16:59:48 -0700
Message-ID: <1122767988.111262.20180_at_z14g2000cwz.googlegroups.com>
Date: 30 Jul 2005 16:59:48 -0700
Message-ID: <1122767988.111262.20180_at_z14g2000cwz.googlegroups.com>
paul c wrote:
> Marshall Spight wrote:
>
> > ...
> > (read ":" as "has type"; P for parent, C for child)
> > Relation PR : (a : P)
> > Relation CR : (a : C)
> >
> > What is the type of PR join CR?
> >
> > Date&Darwen's TTM says it's a relation of type (a : P).
> > ...
>
> where does it say that?