Re: All hail Neo!
From: Marshall Spight <marshall.spight_at_gmail.com>
Date: 26 Apr 2006 13:21:07 -0700
Message-ID: <1146082867.320207.326470_at_t31g2000cwb.googlegroups.com>
Date: 26 Apr 2006 13:21:07 -0700
Message-ID: <1146082867.320207.326470_at_t31g2000cwb.googlegroups.com>
Bob Badour wrote:
>
> Since null reduces expressibility relative to the RM,
Consider a language, let's say SQL:1992, but with all references to NULL removed. Call it L-N. Consider the same source language but without removing NULL; call it L+N.
For every expression that can be written in L-N, there exists an identical expression in L+N. Furthermore, there exist expressions in L+N that cannot be written in L-N; namely those that use NULL. Hence, L+N is strictly more expressive than L-N.
Let us say you manage to demonstrate an encoding for L-N such that expressions in L+N that use null can be expressed in L-N. All that would do is show that they are equally expressive.
Marshall Received on Wed Apr 26 2006 - 22:21:07 CEST