| Oracle FAQ | Your Portal to the Oracle Knowledge Grid | |
Home -> Community -> Usenet -> comp.databases.theory -> Re: set-valued values
paul c <toledobythesea_at_oohay.ac> wrote in news:TX2eh.439310$1T2.321088
@pd7urf2no:
> It's a conundrum for me. On one hand, if the empty set is contained in
> one extension, de Morgan tells us it is not in the other. On the other
> hand, its lack of an attribute seems to make it a member of both sets.
The relational theory is build on void -- the empty set.
Proof: one postulates the empty set existance. Then one gets the natural numbers in von Neumann numerals:
0 def. {}
1 def. {{}} = {0}
2 def. {{}, {{}}} = {0, 1}
The rest is easy :] -- the rational numbers, real and the rest of mathematique follows. Of course, the relational theory is one part of mathematique. QED.
-- TegiReceived on Fri Dec 08 2006 - 07:26:51 CST
>
> p
>
![]() |
![]() |