# Strange error with svmono and quotation

When I try to use svmono, it runs into a handful of these errors:

Error   Missing number, treated as zero.


The help provided for this:

This is usually caused by a LaTeX command expecting but not finding
either a number or a length as an argument. You may have omitted an
argument, or a square bracket in the text may have been mistaken for
the beginning of an optional argument. This error is also caused by
putting \protect in front of either a length command or a command such
as \value that produces a number.


And

Error   Illegal unit of measure (pt inserted).


And the help for this:

If you just got a

! Missing number, treated as zero.

error, then this is part of the same problem.  If not, it means that
LaTeX was expecting a length as an argument and found a number
instead.  The most common cause of this error is writing 0 instead of
something like 0in for a length of zero, in which case typing return
should result in correct output. However, the error can also be caused
by omitting a command argument.


The location of the errors is in the beginning of the body some quotation environments.

Here's a minimal working example that throws these errors:

\documentclass{svmono}

\begin{document}

\begin{quotation}
Plus grande est
\end{quotation}

\end{document}


The error is thrown between the "g" and "r":

--- TeX said ---
g
l.6   Plus g
rande est


Basically, all the quotation environments whose bodies begin with "plus" or "Plus" throw this error.

I can get around the error by writing "{plus}" or "{Plus}" instead, but why would I have to do this?

• "Running into font issues" isn't exactly a specific diagnosis. Please post an MWE and state which font issues you encounter.
– Mico
Oct 23, 2016 at 7:33
• if it's this one groups.inf.ed.ac.uk/vision/F4K_BOOK/SPRINGER/styles/svmono.cls I couldn't see anything (although I didn't try) but if you are using the class to submit to springer and they are using a pdftex workflow xetex support isn't really an issue. Oct 23, 2016 at 7:53
• @Mico I've added more detail. It actually isn't a font error but some issue with units and the quotation environment. Oct 24, 2016 at 18:52
• That does not help anything. Please provide a minimal example as others gave already requested. Then they can copy it and test it (without having to add anything) and see if it works on their systems. Right now we are drawing blanks as we do not know any details about your doc other than you are using svmono and have an issue with quotation Oct 24, 2016 at 19:10
• @daleif I can't reproduce it with a minimal working example, nor does LaTeX give any other errors and warnings that what I quoted above. Oct 24, 2016 at 19:59

The problem is in the way svmono implements the quotation environment.

The definition is

\renewenvironment{quotation}
\list{}{\listparindent12\p@%
\leftmargin=12\p@%
\itemindent    \listparindent
\rightmargin   \leftmargin
\parsep        \z@ \@plus\p@%
\small}%
\item\relax\hskip-\listparindent}
{\endlist}


When the quotation starts with the words "plus" or "minus" these words are interpreted as basic TeX commands for adding or subtracting lengths. Thus one has either to terminate the computation or enclosing the computation in a group.

Thus replacing the line

\item\relax\hskip-\listparindent


with

\item\relax\hskip-\listparindent\relax


prevents the words "plus" and "minus" to be understood as operators.

• Nice deduction, hadn't seen that one coming. Oct 25, 2016 at 5:27
• Better yet, \item\relax\hspace{-\listparindent} Oct 25, 2016 at 7:11