# Extra extra, get your red hot glyphs here...

• To: math-font-discuss@cogs.susx.ac.uk
• Subject: Extra extra, get your red hot glyphs here...
• From: alanje@cogs.susx.ac.uk (Alan Jeffrey)
• Date: Thu, 5 Aug 93 21:57 BST

On the topic of Justin's glyph list...

\item Two sized $\bigcirc$ with $\vee$ inside.  $\bigcirc \!\!\!\!\!\vee$ proposed name: ovee.
\item Two sized $\bigcirc$ with $\wedge$ inside.  $\bigcirc \!\!\!\!\!\wedge$ proposed name owedge.

As far as I'm aware nobody has *ever* used these glyphs in a paper.  I
put them in St Mary's Road because I needed them at the time, but I
shortly abandoned writing the paper they were going to be used in.
Please don't include them!  (If we are going to, we need to include <ovee>
and <owedge> as well as <bigovee> and <bigowedge> which are the ones you
described.)

\item alan J wrote:\\ \verb=\arrownot and \Arrownot, so that for
example= \\ \verb= \arrownot\mapsto is visually compatible with
\nrightarrow.= \\ \textit{That is not very clear to me.}
\item Alan: Add the building blocks' for the AMS negated relations,
for example a \verb|\arrownot| to build \verb|\nlongrightarrow|
and \verb|\nrightarrowfill|.

These are actually the same thing.  Since I wrote that, I've realized we
really need an arrow building kit', which is something I'm still kicking
ideas around for.  I'll post once I've got something coherent to say!

\item General parallel \texttt{\string\bigparallel}
\item Interleaving $|\!|\!|$
[bb: I'm not sure about the spacing or meaning but we've had
requests for triple verts as delimiters.]
\item General interleaving \string\biginterleaving

Interleaving' and parallel' are used in (at least) three different ways:

* as delimiters ||foo|| and |||foo|||.  These should come in
normal-sized and extensible versions.

* as binary operators p || q and p ||| q.  These can be the same glyphs
as for the normal-sized delimiters.

* as big' operators ||_i p_i and |||_i p_i (similar to \bigcup).  These
should come in textstyle and displaystyle versions.

The big operators aren't the same glyphs as the extensible delimiters.

\item A U' with a dot in it, and an upside down U' with a dot in
it.  Something like: $\bigcup\!\!\!\!\cdot$\ \ and
$\bigcap\!\!\!\!\cdot$

If we're including \bigcupdot and \bigcapdot, we should include \cupdot
and \capdot as well.

\item From JMR: something like this: $\raise .1cm \hbox{$|$}\!\_$
maybe the same upside down.

JMR: could you explain what this is, how it's used, why it isn't just
$\lfloor$, etc.

\item Possibly something like $\bar($ and $\bar)$ if the bar was
touching, maybe called banana brackets.

These aren't banana brackets!  Banana brackets look (sort of) like $(\!|$
and $|\!)$.  Or they look like bananas if you believe Jeremy...

The St. Mary Road font includes samples of them, in a
line-drawing style. Since I have not seen them in real use, I
cannot comment, if this style or rather the look of \& in cmr is
appropriate.}

The St Mary's Road ones are abominations.  The inverted ampersand should
have the same shape as the default ampersand, so in CM math, it should be
an inverted CMR ampersand.  It should go in the same font as the
ampersand (which almost certainly means MC).

\item lightning (wasy) --- I don't think this belongs in maths.

It is actually used though!  It means interrupt' in process theory, c.f.
Communicating Sequential Processes, Hoare, Prentice Hall 1985.  I don't
know how widely used outside process theory it is though...

\item Must not forget the three versions of the \# hash sign. I
believe some are geometric, and some aren't.

For those who are wondering, those are the slanted hash sign, the upright
hash sign, and the musical sharp sign (which isn't a hash sign at all!)

\item large operator symbols based on ampersand, asterisk, and pound
sign.

Gosh, do people really use these?  Does this mean we have to have the
ordinary <sterling> in the math fonts as well?  And if <sterling> why not
the other currency symbols?  I'm sure some mathematician will find a use
for the generic currency glyph, nobody else seems to have...

Alan.