troff character names for Greek fonts
Mark Brader
> I'm working on ditroff font width tables for Greek fonts for our
> Autologic APS-Micro 5 phototypesetter. There are quite a few
> characters on the APS's Greek fonts that I haven't seen before
> on other devices' Greek fonts ...
> ...
> coppa (a Byzantine character? not Greek...)
> sampi
Perhaps these characters are provided so that one of the old Greek
numeral systems can be typeset. That system was one of the ones
that assigned every letter of the alphabet a numeric value. The
values assigned were 1,2,3,...9, 10,20,30,...90, 100,200,300,...900.
Unfortunately the Greek alphabet is only 24 letters long. To make
it up to the required 27, 3 obsolete characters were inserted:
van between eta and zeta (thus = 6)
koppa between pi and rho (thus = 90)
sampi after omega (thus = 900).
Van looks rather like an s with the top stretched up; if it's not on the
font, I suppose the alternate lower case sigma is close. Koppa is a Q
with the tail pointing straight down, and sampi is like a backwards C
overstruck with an upward-slanted = sign.
Reference: "A History of Mathematical Notations" by Florian Cajori, vol. 1,
1928, reprinted 1974.
Mark Brader
P.S. [1] Please direct any followups to the appropriate single newsgroup.
[2] With all the remarks flying around lately about inaccurate values
attempted to be assigned to pi, I'm surprised that nobody else
has pointed out that the ancient Greeks made it 80... :-)