# Aligned \description

### Code

\documentclass[a4paper,twoside,12pt]{book}
\usepackage[utf8]{inputenc}

\begin{document}
\noindent Let us define:
\begin{description}
\item[$C_{DEP}$] (\euro) depreciation of the machine.
\item[$C_{EN}$] (\euro) energy cost.
\item[$CE$] (\euro /year) energy cost per year.
\item[$CMAT_{(W \geq W_L)}$] (\euro\textcentoldstyle) cost of raw material regarding the conforming'' packages.
\item[$CMAT_{(W < W_L)}$] (\euro\textcentoldstyle) cost of raw material regarding the non conforming'' packages.
\item[$CS$] (\euro\textcentoldstyle) cost of sorting.
\item[$CP$] (\euro\textcentoldstyle) cost of the packaging material.
\item[$c_{pack}$] (\euro /kg) cost of the packaging material per kilogram.
\item[$c_u$] (\euro\textcentoldstyle/g) cost of the raw material per gram.
\item[$\delta$] dummy variable to consider both rework and scrap packages.
\item[$DEP$] (\euro /year) depreciation of the machine per year.
\item[$E(W|W \geq W_L)$] (g/package) expected weight value of the conforming'' packages.
\item[$E(W|W < W_L)$] (g/package) expected weight value of the non conforming'' packages.
\item[$LAB$] (\euro /h) labor cost per hour.
\item[$n_B$] number of conforming'' packages.
\item[$P$] number of packages produced in a specific time interval.
\item[$Q_{pack}$] (kg/package) quantity of the packaging material per package.
\item[$t$] (hours/package) production time.
\item[$W$] (g/package) quantity of product delivered in each package, it can be modeled as a random variable with an unknown distribution.
\item[$W_L$]              (g/package) legal weight of the package. The tolerable negative error in the contents of a prepackage is fixed in accordance with the table below:

\begin{table}[htbp]
\captionsetup{font=small} % Set the caption font size
\begin{center}
\begin{tabular}{cc | cc}

\toprule
\multicolumn{2}{c}{$W_T$ in \si{\gram} or \si{\ml}} & \multicolumn{2}{|c}{Tolerable negative error}\\
\midrule
from    &   to              &   as \% of $W_T$  &     \si{\gram} or \si{\ml}\\
\midrule
5       &   50              &   9               &   -       \\
50      &   100             &   -               &   4.5     \\
100     &   200             &   4.5             &   -       \\
200     &   300             &   -               &   9       \\
300     &   500             &   3               &   -       \\
500     &   1000            &   -               &   15      \\
1000    &   \num{10000}     &   1.5             &   -       \\
\bottomrule

\end{tabular}
\vspace{5pt} % a little space to shift the caption down
\caption{tolerable negative error}
\label{tab:legislation}
\end{center}
\end{table}
\item[$W_T$] (g) Target weight value of a package.
\item[$TI$] (s) time used to take care of the non conforming'' packages.
\item[$WH$] (hours/year) working hours of the machine per year.

\end{description}
\end{document}


### Question

Is there any easy way to align symbols, Units of measurement and descriptions? I'd like to avoid using tables to align. I'd like something like:

SYMBOL    (Units)    Long long long long long long long long long long long long long
SYMBOL_2  (Units)    Long long long long long long long long long long long long long
Long long long long long long long long long long long long long


This possible solution utilizes the technique introduced in Description list with aligned descriptions and define a macro called abox box of 3cm length, with left alignment, for the symbols, so that a second column alignment is established.

Code

\documentclass[a4paper,twoside,12pt]{book}
\usepackage[margin=1cm]{geometry}
\usepackage[utf8]{inputenc}
\usepackage{eurosym,booktabs}
%\usepackage{amsmath,amssymb,latexsym}
\usepackage{textcomp,siunitx,caption}
\usepackage{calc}
\usepackage{enumitem}

\def\abox#1{\leavevmode\hbox to 3cm{#1\ \hfill}}

\begin{document}

\noindent Let us define:
\begin{description}[leftmargin=6.2cm,labelwidth=\widthof{$E(W|W < W_L)$}]
\item[$C_{DEP}$]  \abox{(\euro)} depreciation of the machine.
\item[$C_{EN}$]   \abox{(\euro)}  energy cost.
\item[$CE$]       \abox{(\euro/year)} energy cost per year.
\item[$CMAT_{(W \geq W_L)}$] \abox{(\euro\textcentoldstyle)} cost of raw material regarding the conforming'' packages.
\item[$CMAT_{(W < W_L)}$]    \abox{(\euro\textcentoldstyle)} cost of raw material regarding the non conforming'' packages.
\item[$CS$]       \abox{(\euro\textcentoldstyle)} cost of sorting.
\item[$CP$]       \abox{(\euro\textcentoldstyle)} cost of the packaging material.
\item[$c_{pack}$] \abox{(\euro /kg)} cost of the packaging material per kilogram.
\item[$c_u$]      \abox{(\euro\textcentoldstyle/g)} cost of the raw material per gram.
\item[$\delta$]   \abox{} dummy variable to consider both rework and scrap packages.
\item[$DEP$]      \abox{(\euro /year)} depreciation of the machine per year.
\item[$E(W|W \geq W_L)$]\abox{(g/package)} expected weight value of the conforming'' packages.
\item[$E(W|W < W_L)$]   \abox{(g/package)} expected weight value of the non conforming'' packages.
\item[$LAB$]      \abox{(\euro /h)} labor cost per hour.
\item[$n_B$]      \abox{} number of conforming'' packages.
\item[$P$]        \abox{} number of packages produced in a specific time interval.
\item[$Q_{pack}$] \abox{(kg/package)} quantity of the packaging material per package.
\item[$t$]        \abox{(hours/package)} production time.
\item[$W$]        \abox{(g/package)} quantity of product delivered in each package, it can be modeled as a random variable with an unknown distribution.
\item[$W_L$]      \abox{(g/package)} legal weight of the package. The tolerable negative error in the contents of a prepackage is fixed in accordance with the table below:

\begin{table}[htbp]
\captionsetup{font=small} % Set the caption font size
\begin{center}
\begin{tabular}{cc | cc}

\toprule
\multicolumn{2}{c}{$W_T$ in \si{\gram} or \si{\ml}} & \multicolumn{2}{|c}{Tolerable negative error}\\
\midrule
from    &   to              &   as \% of $W_T$  &     \si{\gram} or \si{\ml}\\
\midrule
5       &   50              &   9               &   -       \\
50      &   100             &   -               &   4.5     \\
100     &   200             &   4.5             &   -       \\
200     &   300             &   -               &   9       \\
300     &   500             &   3               &   -       \\
500     &   1000            &   -               &   15      \\
1000    &   \num{10000}     &   1.5             &   -       \\
\bottomrule

\end{tabular}
\vspace{5pt} % a little space to shift the caption down
\caption{tolerable negative error}
\label{tab:legislation}
\end{center}
\end{table}
\item[$W_T$] \abox{(g)} Target weight value of a package.
\item[$TI$]  \abox{(s)} time used to take care of the non conforming'' packages.
\item[$WH$]  \abox{(hours/year)} working hours of the machine per year.
\end{description}
\end{document}


Modify the values of \onelen and \twolen to your needs and use \myitem instead of \item as in the following example:

\documentclass[a4paper,twoside,12pt]{book}
\usepackage[margin=1cm]{geometry}
\usepackage[utf8]{inputenc}
\usepackage{eurosym}
\usepackage{textcomp}
\usepackage{siunitx}
\usepackage{caption,booktabs}
\usepackage{enumitem}

\newlength\onelen
\newlength\twolen

\setlength\onelen{6.35cm}
\setlength\twolen{3cm}

\newcommand{\myitem}[2]{%
\item[#1] \makebox[\twolen][l]{#2}%
}

\begin{document}
\noindent Let us define:
\begin{description}[leftmargin=\onelen,labelwidth=3cm]
\myitem{$C_{DEP}$}{(\euro)} depreciation of the machine.
\myitem{$C_{EN}$}{(\euro)} energy cost.
\myitem{$CE$}{(\euro /year)} energy cost per year.
\myitem{$CMAT_{(W \geq W_L)}$}{(\euro\textcentoldstyle)} cost of raw material regarding the conforming'' packages.
\myitem{$CMAT_{(W < W_L)}$}{(\euro\textcentoldstyle)} cost of raw material regarding the non conforming'' packages.
\myitem{$CS$}{(\euro\textcentoldstyle)} cost of sorting.
\myitem{$CP$}{(\euro\textcentoldstyle)} cost of the packaging material.
\myitem{$c_{pack}$}{(\euro /kg)} cost of the packaging material per kilogram.
\myitem{$c_u$}{(\euro\textcentoldstyle/g)} cost of the raw material per gram.
\myitem{$\delta$}{} dummy variable to consider both rework and scrap packages.
\myitem{$DEP$}{(\euro /year)} depreciation of the machine per year.
\myitem{$E{(W|W \geq W_L)}$}{(g/package)} expected weight value of the conforming'' packages.
\myitem{$E(W|W < W_L)$}{{(g/package)}} expected weight value of the non conforming'' packages.
\myitem{$LAB$}{(\euro /h)} labor cost per hour.
\myitem{$n_B$}{} number of conforming'' packages.
\myitem{$P$}{} number of packages produced in a specific time interval.
\myitem{$Q_{pack}$}{(kg/package)} quantity of the packaging material per package.
\myitem{$t$}{(hours/package)} production time.
\myitem{$W$}{(g/package)} quantity of product delivered in each package, it can be modeled as a random variable with an unknown distribution.
\myitem{$W_L$}{(g/package)} legal weight of the package. The tolerable negative error in the contents of a prepackage is fixed in accordance with the table below:

\begin{table}[htbp]
\captionsetup{font=small} % Set the caption font size
\begin{center}
\begin{tabular}{cc | cc}

\toprule
\multicolumn{2}{c}{$W_T$ in \si{\gram} or \si{\ml}} & \multicolumn{2}{|c}{Tolerable negative error}\\
\midrule
from    &   to              &   as \% of $W_T$  &     \si{\gram} or \si{\ml}\\
\midrule
5       &   50              &   9               &   -       \\
50      &   100             &   -               &   4.5     \\
100     &   200             &   4.5             &   -       \\
200     &   300             &   -               &   9       \\
300     &   500             &   3               &   -       \\
500     &   1000            &   -               &   15      \\
1000    &   \num{10000}     &   1.5             &   -       \\
\bottomrule

\end{tabular}
\vspace{5pt} % a little space to shift the caption down
\caption{tolerable negative error}
\label{tab:legislation}
\end{center}
\end{table}
\myitem{$W_T$}{(g)} Target weight value of a package.
\myitem{$TI$}{(s)} time used to take care of the non conforming'' packages.
\myitem{$WH$}{(hours/year)} working hours of the machine per year.

\end{description}
\end{document}


If you just want to use a description list and do as David suggested, stuffing everything into the item description, you can get a cheap alignment using \rlap and \phantom. (Note, the arguments to the two \phantom commands should be the longest entries in the "symbol" and "unit" field respectively.)

\documentclass{article}
\usepackage[official]{eurosym}
\usepackage[utf8]{inputenc}

\newcommand\itemd[2]{\item[\rlap{#1}\phantom{$CMAT_{(W<W_L)}$} \rlap{(#2)}\phantom{\euro{}
/ package}]}

\begin{document}
\noindent Let us define:
\begin{description}
\itemd{$C_{DEP}$}{\euro{}} depreciation of the machine.
\itemd{$C_{EN}$}{\euro{}} energy cost.
\itemd{$CE$}{\euro{} /year} energy cost per year.
\itemd{$CMAT_{(W \geq W_L)}$}{\euro{}} cost of raw
material regarding the conforming'' packages.
\itemd{$CMAT_{(W < W_L)}$}{\euro{}} cost of raw
material regarding the non conforming'' packages.
\itemd{$CS$}{\euro{}} cost of sorting.
\itemd{$c_{pack}$}{\euro{} /kg} cost of the packaging material per
kilogram.
\itemd{$c_u$}{\euro{}/g} cost of the raw material per
gram.
\itemd{$\delta$}{none} dummy variable to consider both rework and scrap
packages.
\itemd{$DEP$}{\euro{} /year} depreciation of the machine per year.
\itemd{$E(W|W \geq W_L)$}{g/package} expected weight value of the
conforming'' packages.
\end{description}
\end{document}


(Posting CW as I don't like this output that much: with many symbols and units of disparate lengths, any aligned output would look awkward.)

• Incidentally, I couldn't get your MWE to build as it was missing (for me) the \euro and \textcentoldstyle commands. – Willie Wong Mar 20 '14 at 16:01

use a tablex it supports longtable as werl as a tabularx with a possible pagebreak:

\documentclass[a4paper,twoside]{book}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{geometry}
\usepackage{textcomp,eurosym}
\usepackage{ltablex}
\usepackage{booktabs}
\usepackage{siunitx}
\usepackage{caption}
\captionsetup{font=small} % Set the caption font size

\begin{document}
\noindent Let us define:

\noindent
\begin{tabularx}{\linewidth}{@{}r X@{}}
$C_{DEP}$ (\euro) & depreciation of the machine.\\
$C_{EN}$  (\euro) & energy cost.\\
$CE$      (\euro /year) & energy cost per year.\\
$CMAT_{(W \geq W_L)}$ (\euro\textcentoldstyle) & cost of raw material regarding the conforming'' packages.\\
$CMAT_{(W < W_L)}$ (\euro\textcentoldstyle) & cost of raw material regarding the non conforming'' packages.\\
$CS$ (\euro\textcentoldstyle) & cost of sorting.\\
$CP$ (\euro\textcentoldstyle) & cost of the packaging material.\\
$c_{pack}$ (\euro /kg) & cost of the packaging material per kilogram.\\
$c_u$ (\euro\textcentoldstyle/g) & cost of the raw material per gram.\\
$\delta$ & dummy variable to consider both rework and scrap packages.\\
$DEP$ (\euro /year) & depreciation of the machine per year.\\
$E(W|W \geq W_L)$ (g/package) & expected weight value of the conforming'' packages.\\
$E(W|W < W_L)$ (g/package) & expected weight value of the non conforming'' packages.\\
$LAB$ (\euro /h) & labor cost per hour.\\
$n_B$ & number of conforming'' packages.\\
$P$ & number of packages produced in a specific time interval.\\
$Q_{pack}$ (kg/package) & quantity of the packaging material per package.\\
$t$ (hours/package) & production time.\\
$W$ (g/package) & quantity of product delivered in each package, it can be modeled as a random variable with an unknown distribution.\\
$W_L$ (g/package) & legal weight of the package. The tolerable negative error in the contents of a prepackage is fixed in accordance with the table below:
\end{tabularx}

\begin{longtable}{cc | cc}\toprule
\multicolumn{2}{c}{$W_T$ in \si{\gram} or \si{\ml}} & \multicolumn{2}{|c}{Tolerable negative error}\\
\midrule
from    &   to              &   as \% of $W_T$  &     \si{\gram} or \si{\ml}\\
\midrule
5       &   50              &   9               &   -       \\
50      &   100             &   -               &   4.5     \\
100     &   200             &   4.5             &   -       \\
200     &   300             &   -               &   9       \\
300     &   500             &   3               &   -       \\
500     &   1000            &   -               &   15      \\
1000    &   \num{10000}     &   1.5             &   -       \\\bottomrule
\caption{tolerable negative error}\label{tab:legislation} \\
\end{longtable}

\begin{tabularx}{\linewidth}{@{}r l X@{}}
$W_T$ (g) & Target weight value of a package.\\
$TI$ (s) & time used to take care of the non conforming'' packages.\\
$WH$ (hours/year) & working hours of the machine per year.\\
\end{tabularx}

\end{document}