[PING][PATCH][BZ #17787] Fix exponents in manual.

[Joseph Myers]

On Tue, 16 Jun 2015, Ondřej Bílka wrote:

> Ping, if you have better idea I would like it.

I've looked back at the previous discussion.  It seems clear enough that:

* It's a bad idea to duplicate parts of sentences that don't need 
duplicating.  Conditionals in the main manual should be around lines with 
nothing more than the single word using @math.

* It should be possible to use a Texinfo macro for this and so avoid any 
conditionals at all in the main manual.  Something like (untested)

@iftex
@macro twoexp{exp}
2^{\exp\}
@end macro
@end iftex
@ifnottex
@macro twoexp{exp}
2^{exp}
@end macro
@end itnottex

(and then use @twoexp{63} etc.).

-- 
Joseph S. Myers
joseph@codesourcery.com