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Re: [zzdev] :zz: Ranks (was: Re: STILL NOT WORKING
- To: zzdev@xxxxxxxxxx
- Subject: Re: [zzdev] :zz: Ranks (was: Re: STILL NOT WORKING
- From: Mark-Jason Dominus <mjd@xxxxxxxxxx>
- Date: Wed, 28 Oct 1998 19:41:49 -0500
- In-reply-to: Your message of "Wed, 28 Oct 1998 17:02:40 +0900." <3.0.3.32.19981028170240.00f8f2e0@xxxxxxxxxxxxxxxxxxx>
- Reply-to: zzdev@xxxxxxxxxx
> "Rank" is the generalized term for "row" and "column",
There should be a word for a collection of connected cells in the same
rank. Example:
A--B--C--D P--Q--R
| |
N1-N2-N3-N4-N5-N6
Unless I misundestand youm all seven cells ABCD PQR are in the same
rank, but ABCD are in one blurfl and PQR are in a separate blurfl.
This is the thing I have been calling `pier', but I don't like that.
My vote is for `beam' unless you already have a name for it.
> However, a rank may be a loop.... Already a number of scientists
> have shaken their heads and mumbled nervously about this. We don't
> know any formal description that fits in known mathematics.
Oh, it's no trouble. Mathematicians call it a `product space', and
they are quite happy to take products of circles. If you take the
product of two line segments, you get a plane segment. If you take
the product of a segment and a circle, you get a cylinder. If you
take the product of two circles, you get a torus.
If you have a ZZ object in three dimensions all of which are
ringranks, there are a lot of mathematicians who will come along and
say, ``Ah, yes, S1-cubed.'' (S1 is topological jargon for the
circle.)
Hmm, I'm suddenly inspired to make a ZZ object that is shaped like a
Klein bottle. It shouldn't take long.