[Tuglist] Environment slide in pdfscreen.sty

David Kastrup tuglist@tug.org.in
12 Jun 2002 16:32:16 +0200

Manoj K N <knm@india.ti.com> writes:

> I knew what \makeatletter and \makeatother do, but was doing some
> experiments. My main concern was not LaTeX failing to understand the \def
> command, but why the first error I got was about c@\@captype being not
> defined. Reading latex.ltx, I felt that it should have been about the
> counter \@captype not being defined.

A counter xxx is stored in a control sequence of the name \c@xxx.  So
your error message _was_ about the counter \@captype.  However, LaTeX
tries to catch this error itself and warn the user, by checking for
the presence of \c@xxx, or in this case \c@\@captype (so to say).
Since it does this check by checking for
\csname c@\@captype\endcsname in this case, and since \@captype is
not defined, _TeX_ now complains that it cannot complete \csname
before LaTeX has a chance to complain that the completed \csname is
nothing that it could recognize as a counter.

David Kastrup, Kriemhildstr. 15, 44793 Bochum
Email: David.Kastrup@t-online.de