>>56
"Secondly, I can look at this semantically."
You could, but linguistics has very, very little place in math. You can't call a mathematician wrong on a linguistic basis if he's got the concept right. If the proof's wording sucks, come on in. Else, gtfo.
ABCDEFGHIJKLMNOPQRSTUVWXY and Z are all also defined symbols which hold meaning for you. But are they really letters? According to you, these would be defined symbols that represent what we call "letters." Hiragana are letters, too. But Hiragana can be represented by combinations of two or more of the 26 symbols I just named.