Date: Sep 30, 2017 4:18 PM
Author: Me
Subject: Re: No Below Zero... or a name for the absence of quantity...
On Saturday, September 30, 2017 at 9:39:41 PM UTC+2, mitchr...@gmail.com wrote:

> You cannot take away more than is there.

Indeed.

> You cannot subtract more quantity is there.

In a certain sense, yes.

> You can only subtract an equal or less quantity

> than is there.

In a certain sense, yes.

You will find this properties in set theory. A set is empty or not empty, there is no "negative" set.

For example:

{1, 2, 3} \ {1, 2, 3, 4} = {}

Not something like

-{4} or {-4} or whatever.

Same in the context of the natural numbers,

For n,m e IN with n < m, "n - m" is simply not defined.