Re: Proposal: 6NF
From: Jan Hidders <hidders_at_gmail.com>
Date: 12 Oct 2006 05:31:15 -0700
Message-ID: <1160656275.240137.200620_at_e3g2000cwe.googlegroups.com>
Date: 12 Oct 2006 05:31:15 -0700
Message-ID: <1160656275.240137.200620_at_e3g2000cwe.googlegroups.com>
vc wrote:
>
> More interestingly, why bother with a trivial fact that Z may be
> [considered] a subset of R in whatever sense ?
Because you want a simple formalization of subtyping a la Cardelli and Wegner where subtyping coincides with being a subset. It means that the meanig of the + operation in (a + b) can be considered independent of the type of a and b.
- Jan Hidders