Guide to LaTeX (4th Edition) (Tools and Techniques

C.4. T E X error messages 427
the text processing. This message appears when one of these buffers is
full and can no longer be used. The name of the buffer and its maximum
size are printed in the square brackets of the error indicator. With this
message, the T E X processing is terminated. The source of this problem is
hardly ever due to insufficient memory, no matter how much complicated
text is being processed, but rather to an error in the text itself. The
methods described in Section C.6 may be applied to try to detect the true
error.
The following descriptions of the various buffers should help to decide
whether the storage capacity allotted to T E X really is too small and to
explain what one might do to correct this.
buffer size The problem here can be that the text in the argument of a sectioning,
\caption, \addcontentsline, or \addtocontents command is
too long. The message then normally appears when the \end{document}
command is processed, but may also arise at one of \tableofcontents,
\listoffigures, or \listoftables. The way to avoid this is to use the
optional argument for the short form of the heading text (Sections 3.3.3
and 7.4). Indeed, such a long entry in the table of contents is a nuisance
anyway and should be shortened. After the correction has been made in the
input text, the previous L AT E X.aux file must be deleted before reprocessing.
This problem can occur on a PC if a word processing program has been
used to generate the input text instead of a text editor. Some of these
programs put an entire paragraph into a single line even though the text
on the monitor is broken up into lines.
exception dictionary The list of hyphenation exceptions that have been entered
with the \hyphenation commands has become too large. Words
used less frequently should be removed and their possible word divisions
indicated explicitly with the \- command.
hash size The source file contains too many command definitions or uses too
many cross-reference markers. This does not mean that the input text
really needs all these commands, for it may be that the user has developed
a large collection of private commands that are stored in a single file and
read into every document, whether they are all applicable or not.
input stack size An overflow of this buffer is probably due to a mistake in a
command definition. For example, the command defined with
\newcommand{\com}{One more \com}
produces One more {One more {...One more \com}...}} going on for
ever, since it continually calls itself. Actually, it does not go on for ever,
but only until this buffer is full.
main memory size This buffer contains the text for the page currently being
processed. It also overflows if a recursively defined command has been
called. However, the more usual reasons are: (1) a large number of very
complicated commands have been defined on one page; (2) there are too