Date: Feb 11, 2013 3:08 AM
Author: William Elliot
Subject: Minimal Hausdorff Topology
On Mon, 11 Feb 2013, fom wrote:

> I am wondering about diagram for

> example 100, Minimal Hausdorff Topology.

From what book?

> The "special" basis neighborhoods in

> the diagram do not seem to coincide

> with the defining conditions.

>

> The second coordinate has j>n for that

> n indexing the basis neighborhood,

> but the diagram seems to indicate j<n.

It does not.

> Also, if I am correct about the error

> in the diagram, then should not the

> inequality be changed to j>=n so that

> there is a basis neighborhood associated

> with the first row of the diagram as

> with every other row?

>

No, it makes no difference if it's j >= n or j > n.

> I am probably just misreading the

> definition. But it has me confused.

>

It takes some study to understand.

There are orders, that of A and that of Z+.

The order for Z+ begins at the bottom with 1

and goes to the top. Notice how at the top

the rows of dots are closer that at the bottom

indicating a two dimensional dot, dot, dot.

for the rows.