[plt-scheme] Re: Why "lambda"?

From: Erich Rast (erich at snafu.de)
Date: Mon Jun 1 05:44:00 EDT 2009

> Insofar as the message is - there's a good reason why we do this
> (clarity, avoids ambiguity, makes no difference if you abstract
> etc...). No. I ain't swallowing it.

I tried to avoid it, but can't resist any longer. :O

There is a good reason for Greek letters and it's not just convention.
I'm not sure how much you've been exposed to formal logic so far, but at
least in this domain I'd say it's impossible to have a clear, correct
and concise notation without using additional letters such as the Greek
ones. Arbitrary symbols, usually taken from a huge Latex symbol list,
are harder to read than Greek letters, and when you write down a
complete logic including some meta-theorems, you'll quickly run out of
ordinary Roman letters. Having the Greek alphabet is a matter of
necessity when  you're doing logic, because you frequently need
different *types* of letters. Try to distinguish normal, italic and
boldface 'A' on the blackboard---impossible. Even upper vs. lower-case
letters can be a pain to write on the blackboard.

IMHO, the most important thing with 'strange' letters is that (a) you
have to know how to pronounce them, and (b) they need to be easily
writable on the blackboard. Greek letters are fine with both respects
and beat any kind of hand-made symbol at anytime. Personally, I have
problems with Kyrillic, some of the less common Hebrew letters, and old
German Fraktur fonts, though. Yes, I've seen logic books that used the
whole Kyrillic alphabet, which might be easy for a Russian logician, but
is hard to read for someone who never learned Russian. Fraktur, on the
other hand, is not hard to read, but in my opinion impossible to write
and read on the blackboard.

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