# Missing number, treated as zero <to be read again> \c@list \item f or \item o

I sat for hours and couldn't figure out where am missing. I think the answer is simple but I am really stuck at it. Please help !!!

    \documentclass{report}
\textwidth 316pt
\begin{document}

We number the properties by a double numbering technique,
such that it is easy to refer to them.

\begin{enumerate}
\item
The observed properties hold for all $S$--boxes.
We analyze if the output of an $S$--box can or cannot change
if one modifies the inputs of an $S$--box in the following way\nobreak\hspace{0.7mm}:
\begin{list}{(\alph{list})}{\itemsep 0mm}
\item fix the inputs $e$ and $f$E
\item one is allowed to change $c$ and $d$ to an arbitrary value $c'$ and $d'$
\item one changes the inputs $a$ and $b$ as described in the properties
\end{list}
\begin{description}{1.4.}
\item[1.1.]
$\neg (\forall c,d,c',d',e,f : S_{i}(0,0,c,d,e,f) \not= S_{i}(1,0,c',d',e,f) )$
\item[1.2.]
$\neg (\forall c,d,c',d',e,f : S_{i}(0,1,c,d,e,f) \not= S_{i}(1,1,c',d',e,f) )$
\item[1.3.]
$\forall c,d,c',d',e,f : S_{i}(0,1,c,d,e,f) \not= S_{i}(1,0,c',d',e,f)$
\item[1.4.]
$\forall c,d,c',d',e,f : S_{i}(0,0,c,d,e,f) \not= S_{i}(1,1,c',d',e,f)$
\end{description}

\end{document}


One more error am getting in above is (in the description): "LaTeX Error: Something's wrong--perhaps a missing \item" at following lines please help me with this. I will be very grateful.

Am trying for something like this: • What is{1.4} on entering the environment supposed to be there for? – Bernard May 4 '17 at 23:33
• Why is this tagged latex-2.09 when it clearly isn't? – cfr May 4 '17 at 23:33
• You shouldn't usually need to use list directly in a document. What are you trying to do exactly? What is \alph{list} supposed to do? – cfr May 4 '17 at 23:36
• Hello, @cfr I have uploaded a image of what am looking for. Thanks !!! – Manohar Katam May 5 '17 at 0:10

If you're planning on using the list environment to create a list-like structure, you need to be familiar with its syntax. From source2e (section 54 List, and related environments, p 269):

The generic commands for creating an indented environment – enumerate, itemize, quote, etc – are:

\list{<LABEL>}{<COMMANDS>} ... \endlist


which can be invoked by the user as the list environment. The LABEL argument specifies item labeling. COMMANDS contains commands for changing the horizontal and vertical spacing parameters.

Each item of the environment is begun by the command \item[ITEMLABEL] which produces an item labeled by ITEMLABEL. If the argument is missing, then the LABEL argument of the \list command is used as the item label. The label is formed by putting \makelabel{<ITEMLABEL>} in an hbox whose width is either its natural width or else \labelwidth, whichever is larger. The \list command defines \makelabel to have the default definition:

\makelabel{<ARG>} == BEGIN \hfil ARG END


which, for a label of width less than \labelwidth, puts the label flushright, \labelsep to the left of the item’s text. However, \makelabel can be \let to another command by the \list's COMMANDS argument.

A \usecounter{<foo>} command in the second argument causes the counter foo to be initialized to zero, and stepped by every \item command without an argument. (\label commands within the list refer to this counter.)

It's important to note the last paragraph, where a \usecounter{<counter>} identifies the counter to be used with the list. You haven't defined a counter, although you do say it should be list.

Instead, let's define the counter to be mylistcntr and add \usecounter{mylistcntr} to the second argument for list: \documentclass{report}

\newcounter{mylistcntr}

\begin{document}

We number the properties by a double numbering technique,
such that it is easy to refer to them.

\begin{enumerate}
\item
The observed properties hold for all $S$--boxes.
We analyze if the output of an $S$--box can or cannot change
if one modifies the inputs of an $S$--box in the following way:
\begin{list}{(\alph{mylistcntr})}{\usecounter{mylistcntr}\itemsep 0mm}
\item fix the inputs $e$ and $f$E
\item one is allowed to change $c$ and $d$ to an arbitrary value $c'$ and $d'$
\item one changes the inputs $a$ and $b$ as described in the properties
\end{list}
\begin{description}
\item[1.1.]
$\neg (\forall c,d,c',d',e,f : S_i(0,0,c,d,e,f) \neq S_i(1,0,c',d',e,f) )$
\item[1.2.]
$\neg (\forall c,d,c',d',e,f : S_i(0,1,c,d,e,f) \neq S_i(1,1,c',d',e,f) )$
\item[1.3.]
$\forall c,d,c',d',e,f : S_i(0,1,c,d,e,f) \neq S_i(1,0,c',d',e,f)$
\item[1.4.]
$\forall c,d,c',d',e,f : S_i(0,0,c,d,e,f) \neq S_i(1,1,c',d',e,f)$
\end{description}
\end{enumerate}

\end{document}


For a left-aligned enumeration (a), (b), ... you can use

\begin{list}
{(\alph{mylistcntr})}
{\usecounter{mylistcntr}%
\def\makelabel#1{\rlap{#1}\hss}% Left-aligned label
\itemsep 0mm}


You'll also note the following changes (some cosmetic, others not):

1. \not= is similar to \neq (fewer keystrokes).
2. S_{i} is similar to S_i (fewer keystrokes)
3. description is already defines as a list environment, and therefore doesn't take any additional arguments.
• I've seen the gurus state that S_i is not official syntax and it should be S_{i}. People who type the former tend to end up wondering why S_ij doesn't do what they expect .... – cfr May 5 '17 at 1:45
• @cfr: True; use S_{i} when in doubt. – Werner May 5 '17 at 1:53

Your environments are enumerate environments really. Load enumitem and everything will be simple:

\documentclass{report}
\textwidth 316pt
\usepackage{enumitem}
\setlist[enumerate]{wide = 0pt, leftmargin=*}

\begin{document}

We number the properties by a double numbering technique,
such that it is easy to refer to them.

\begin{enumerate}[label=\arabic*., wide, leftmargin=*]
\item
The observed properties hold for all $S$--boxes.
We analyze if the output of an $S$--box can or cannot change
if one modifies the inputs of an $S$--box in the following way\,:

\begin{enumerate}[label=(\alph*), noitemsep]%
\item fix the inputs $e$ and $f$.
\item one is allowed to change $c$ and $d$ to an arbitrary value $c'$ and $d'$.
\item one changes the inputs $a$ and $b$ as described in the properties.
\end{enumerate}
%
\begin{enumerate}[label=\theenumi\arabic*., wide=0pt]
\item
$\neg (\forall c,d,c',d',e,f : S_{i}(0,0,c,d,e,f) \not= S_{i}(1,0,c',d',e,f) )$
\item
$\neg (\forall c,d,c',d',e,f : S_{i}(0,1,c,d,e,f) \not= S_{i}(1,1,c',d',e,f) )$
\item
$\forall c,d,c',d',e,f : S_{i}(0,1,c,d,e,f) \not= S_{i}(1,0,c',d',e,f)$
\item%
$\forall c,d,c',d',e,f : S_{i}(0,0,c,d,e,f) \not= S_{i}(1,1,c',d',e,f)$
\end{enumerate}
\end{enumerate}

\end{document} 