Sharp as mathematics

• To: math-font-discuss@cogs.susx.ac.uk
• Subject: Sharp as mathematics
• From: mdoob@CC.UManitoba.CA
• Date: Mon, 9 Aug 93 11:19:40 CDT

> can people give me examples of the musical sharp sign used in math
> documents

Sometimes $f^\sharp$ will be used to in categorical constructions derived
>from a morphism $f$. I can probably hunt up a real live example if it
is important.

The hash mark # (this is the thing above the three on my keyboard; is it
still an octothorpe after crossing the Atlantic?) is, of course, very
commonly used for set cardinality. It is called the pound symbol in
North America (don't blame me; I'm just the messanger). I've never
seen the currency symbol used in mathematics.

It has become common to used something like $K_{i=1}^\infty$ for continued
fractions.

Cheers,
Michael