# on \eth and \thorn

• To: math-font-discuss@cogs.susx.ac.uk
• Subject: on \eth and \thorn
• From: Ulrik Vieth <vieth@thphy.uni-duesseldorf.de>
• Date: Tue, 16 Dec 1997 14:55:25 +0100

Hi all,

I'm just trying to catch up with last week's mail.

Chris wrote:
> I do not think we should agonise too much about whether or not to
> include in a math encoding some particular symbol that is already
> available in some reasonably widely available font: eg the Icelandic
> letters.

Matthias replied:
> One could imagine a small package diffops' providing math access to a bunch
> of text symbols which are occasionally used as differential operators like
> \eth, \thorn, \dupright, etc. It would just be:
>
> \RequirePackage{amstext}
> \def\thorn{\text{\normalfont\th}}
> ...

> While I agree that it would be nice to have a generic way to access
> text symbols a la \text{<text symbol>}, I think the motivation for putting
> the most commonly used text symbols (\dupright,\eth,\thorn,...) in MC was to
> enable kerning to improve the appearance of things like \dupright\theta.
> This will always be a compromise, since only a small selection of the
> possibly needed text symbols can get a slot in MC. So we should take care
> to find the most frequently used ones.

True.  But I think it is wrong to throw \eth and \thorn into the same
category as the upright d'.  The upright d' and the upright \partial
are standard when typesetting mathematics strictly according to the
rules applicable in pyhsics and engineering, while \eth and \thorn are
a very specialized notation in a very specialized area, which was
probably invented by the author of a particular book, when he ran out
of letters that might otherwise be used to denote some special kinds
of differentials.  (Or are there any other references for their use?)

If you really want to go back to basics and throw out all the
questionable symbols, throwing out \eth and \thorn may well be
justified, but the upright d' should be considered indepently.

BTW, in the latest version of the paper I simply commented out the
paragraph on \eth and \thorn to save some space, so it currently
leaves this question open.

Cheers, Ulrik.