Re: Is {{}} a valid construct?

From: Marshall <marshall.spight_at_gmail.com>
Date: 6 Feb 2007 15:40:24 -0800
Message-ID: <1170805224.527000.160450_at_m58g2000cwm.googlegroups.com>


On Feb 6, 3:18 pm, "Neo" <neo55..._at_hotmail.com> wrote:
> Please ignore prior example, the following is more accurate as apple
> and orange are infact sets (and so are red, stem, orange, pulp, etc
> recursively)
>
> U = {{}, {red, stem}, {orange, pulp}} [1]
> NOT {red, stem} => {{}, {orange, pulp}} [2]
> NOT {orange, pulp} => {{}, {red, stem}} [3]
> NOT {} => {{red, stem}, {orange, pulp}} [4]
> -or-
> {{}, {red, stem}, {orange, pulp}}

Syntax errors again. Lines 2 and 3 attempt to complement sets that do not appear in U. For example, in line 2, you attempt to complement a set that contains red. However red is not an element of U.
Lines 2 and 3 are malformed and meaningless. Your confusion about them leads directly to your thinking that there is some problem with 4.

U                           =   {{}, {red, stem}, {orange, pulp}}
NOT {{red, stem}}     = {{}, {orange, pulp}}
NOT {{orange, pulp}}  = {{}, {red, stem}}
NOT {}                    = {{},{red, stem}, {orange, pulp}}
NOT {{}}                    = {{red, stem}, {orange, pulp}}


Marshall Received on Wed Feb 07 2007 - 00:40:24 CET

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