# just another symbol: opm and omp needed?

• To: math-font-discuss@cogs.susx.ac.uk
• Subject: just another symbol: opm and omp needed?
• From: vieth@convex.rz.uni-duesseldorf.de (Ulrik Vieth)
• Date: Wed, 18 Aug 93 12:25:16 +0200

Hello,

Here are some other symbol I once needed: \opm, \omp. Why?
There is \oplus and \ominus and there is +, -, \pm and \mp,
but there's no \opm and \omp.

I once needed them in a context, where \oplus and \ominus were
used as subscripts to indicate symmetric and antisymmetric wave
functions that were normalized. It is easy to specificy formulas
that include both cases using \pm and \mp, but suddenly there
was no \opm and \omp. I constructed symbols using the circle from
the copyright sign, but that was not actually the perfect size.

Does anybody else need these symbols? Judging as an ignorant user,
who never actually designed characters with METAFONT, these symbols
should not be too difficult to make, since all that's needed is
the circle from \oplus and the \pm or \mp in the middle.
But I might be wrong about that ...

Perhaps it would have been better to use encircled + and - instead
of \opm and \omp in that case since \oplus and \ominus weren't use
as binary operators anyway.

Greetings,

Ulrik Vieth.