GRINDEF in lower case

[KMP at MIT-MC (Kent M. Pitman)]

Well, I don't agree that lower case code is more readable than uppercase
code. Fortunately, my reason for not implementing that needn't be dependent
on this dislike: We had some discussion a while back in which I and others
pointed out that you cannot correctly decide what to downcase and what
to leave upcased. There is no way to distinguish between code that was typed
in by |...| from stuff that was not. Eg, 

	(+ |X| X)

would print out as 

	(+ x x)

under your scheme since after reading there is no way to detect the input
syntax that was used. This would break code, so we can't do it. Besides that,
it would be slow, but that's a lesser issue and not the criterial one.
-kmp