Path: utzoo!attcan!uunet!wuarchive!zaphod.mps.ohio-state.edu!ub!mdeck
From: mdeck@sybil.cs.Buffalo.EDU (Mary Deck)
Newsgroups: comp.text.tex
Subject: TeX and marks
Keywords: mark
Message-ID: <41700@eerie.acsu.Buffalo.EDU>
Date: 19 Oct 90 21:55:12 GMT
Sender: news@acsu.Buffalo.EDU
Organization: State University of New York at Buffalo/Comp Sci
Lines: 41
Nntp-Posting-Host: sybil.cs.buffalo.edu
Originator: mdeck@sybil.cs.Buffalo.EDU

Hi, all.  I'm trying to help a professor TeX a book he's writing.
It's chock fullof exercises.  He wants to put the exercise numbers in
the odd-numbered pages' headlines.  Ok.  So I \mark{\the\exrno} (where
\exrno is a count register) in the exercise macro.  No problem.

If \botmark is the same as \topmark, there are no exercises on the
given (odd) page; he wants "Conventions" in the headline of such
pages.  If \firstmark is the same as \botmark, there is one exercise
on the page; "Problem x" should appear in the headline.  Otherwise,
there are more than one exercises on the page; "Problems y--z" should
be in the headline.  So, in the headline macro, I said

	\if\topmark\botmark{Conventions}
	\else\if\firsmark\botmark{Problem \firstmark}
	     \else{Problems \firstmark--\botmark}
	\fi\fi

But, since that didn't work, I tried writing some stuff to a file to
see what TeX was doing.  It *really* surprised me to find out that
\if\topmark\topmark, \if\firstmark\firstmark, and \if\botmark\botmark
are rarely true.  (What?!?!  Something doesn't equal itself?!?!)  I
wrote to the junk file (with \write) the values of \topmark,
\firstmark, and \botmark.  Even when they printed out the same, they
did not test the same. ???

What I would like to know is:
1)  WHY are those \if's not always true?
2)  How can I compare marks?

I am by no means a TeX wiz, but my boss (who's about the closest thing
we have around here) can't figure this out, either, so I don't feel so
bad. :) 

Loads of thanks in advance....

					....Mary
---
Mary M. Deck,  Student Assistant,  User Services
University Computing Services, State University of New York at Buffalo
mdeck@cs.buffalo.edu [Unix]
acsgmmd@ubvms.cc.buffalo.edu [VAX/VMS]