# Re: More on subscripts and superscripts

• To: math-font-discuss@cogs.susx.ac.uk
• Subject: Re: More on subscripts and superscripts
• From: alanje@cogs.susx.ac.uk (Alan Jeffrey)
• Date: Wed, 11 Aug 93 17:55 BST

>(?) _ in math mode can only be subscript OR \_, but not both. If _ is
>made active' via mathcode "8000, it will work all right inside a
>\write (or conversely, it will only break where it would have broken
>before). But generally, I agree with your next words:

I was worried about things like:

\catcode\_=\active
blah_blah $blah_blah \hbox{blah_blah} blah_blah$ blah_blah

inside an \edef or \write.  Just thinking about all the ways that
these sorts of macros can go wrong gives me the shivers!

>Agreed, except I would have put it the other way around: the decision
>to use syntax like {...\over...} for \over and friends was the design
>flaw that necessitated all the jury-rigging around \mathchoice and
>made it difficult to provide a current math style variable.

Absolutely.  I still have no idea why DEK adopted that syntax for
\over and friends.  Oh well...

Alan.