DougC desperately and mebbe even disparately aarghs in
:
: Mebbe I just append all the previous chapters together, and then do a
: search for "Rg", Ri" and "Rt" and see if any other instances come up....
Nah ... don't waste your time ... it's a lower case "t" in print, in RDH4 ...
Anomaly or not. Congrats on finding and pointing it out; it does seem odd...

What would the "t" stand for in the author's mind?

BTW, WRT publishing etc;- even rather representing;- you had an earlier post;

Brief searches even on Greek let alone maths throw up useful indications,

http://www.cs.tut.fi/~jkorpela/math/ and
http://donald.phast.umass.edu/kicons/greek.html for instance; a world ...

Take your time, and seek the best, as well as you can - and collaborate! ;=}))
--
RdM