# Re: Binary Relations, draft 1

• To: support@yandy.com
• Subject: Re: Binary Relations, draft 1
• From: Ulrik Vieth <vieth@thphy.uni-duesseldorf.de>
• Date: Fri, 20 Nov 1998 13:01:47 +0100
• Content-Length: 1440


> Just to confuse the lower case <-> upper case, upright <-> slanted,
> variable <-> constant, single letter <-> multi letter soup some more,
> note that often vectors are written with upright bold letters.
> Particularly in engineering and some applied math.

Yes, indeed, but mostly for lack of easy access to bold italics,
as they should be according to the rules applicable in physics.

> This usually trips up plain TeX users when they get to a vector
> commonly used to denote angular velocity namely a bold omega.  Until
> they find CMMIB.  They are then so happy, that the slant does not
> bother them any.

Indeed, \vec{\omega} is a common thing, but that's not the only case.
I've also seen \vec{\mu}, \vec{\sigma}, \vec{\epsilon} and, of course,
\vec{\nabla}, so the implication is that you need a full alphabet.

The real trouble starts when you get to tensors, which should be
typeset in bold sans serif inclined according to the rules.  Now,
tell me how to make bold sans serif inclined \tens{\epsilon}
(or any other lc. greek) clearly distinguishable from bold italic?

Cheers, Ulrik.

P.S.  Why are we discussing all this?  I thought we've been through
all of it sometime last year.  Probably the only conclusion we can
find is that we a need a complete set of Latin/Greek uc/lc alphabets
in as many styles we can get, including upright, italics,
bold upright, bold italics, bold sans, bold sans inclined, ...