%% %% This is file `delex.tex', generated %% on <1995/4/7> with the docstrip utility (2.2i). %% %% The original source files were: %% %% deleq.dtx (with options: `exempelkod') %% %% Copyright (c) 1994 by Mats Dahlgren . %% All rights reserved. See the file `deleq.ins' for information %% on how you may (re-)distribute the `deleq' package files. %% \documentclass[11pt]{article} %%% add `leqno' if you want left-aligned \usepackage{deleq} %%% equation numbers. \oddsidemargin=0.5cm \evensidemargin=0.5cm \topmargin=-5mm \textheight=23.5cm \textwidth=15.5cm \begin{document} \begin{center} \Large Welcome to the \texttt{deleq} package! \end{center} This is a short document to demonstrate the use of the \texttt{deleq} package and its commands. It uses \deleqver . \texttt{deleq} was written by Mats Dahlgren (\texttt{matsd@physchem.kth.se}). Suggestions for improvements and bug reports are most welcome, see the documentation. \texttt{deleq} is fully compatible with the \texttt{leqno} option. We start this demonstration by a simple and well-known equation to get the equation number counter going: \begin{equation} \sin^2\alpha + \cos^2\alpha = 1 \end{equation} The first example will be to make use of the \texttt{deqn} environment to get a partially numbered equation: \begin{deqn} \sin (-\alpha) = - \sin \alpha \end{deqn} This equation has its cosine companion, here written in the \texttt{ddeqn} environment: \begin{ddeqn} \cos (-\alpha) = \cos \alpha \end{ddeqn} Not so exciting, so far. :--) In the next example we introduce the \texttt{deqarr} environment for writing equations: \begin{deqarr} \sin ( \alpha + \beta ) & = & \sin \alpha \cos \beta + \sin \beta \cos \alpha \\ \sin ( \alpha - \beta ) & = & \sin \alpha \cos \beta - \sin \beta \cos \alpha \label{Demo1} \end{deqarr} where we also have put in the label \texttt{Demo1} in the second equation. Next, notice how the environment \texttt{ddeqar} uses the same main equation number as the previous equations: \begin{ddeqar} \cos ( \alpha + \beta ) & = & \cos \alpha \cos \beta - \sin \alpha \sin \beta \\ \cos ( \alpha - \beta ) & = & \cos \alpha \cos \beta + \sin \alpha \sin \beta \end{ddeqar} Now, we will make another \texttt{eqnarray}-like structure, again in the \texttt{ddeqar} environment: \begin{ddeqar} \sin 2\alpha & = & 2 \sin \alpha \cos \alpha \heqno \label{Demo2} \\ \cos 2\alpha & = & \cos ^2 \alpha - \sin ^2 \alpha \nydeqno \\ \rem{or} & = & 2\cos ^2 \alpha - 1 \end{ddeqar} This example shows the use of \verb$\heqno$ in the first equation, which produces an ordinary equation number. The first equation is also labelled, with the label \texttt{Demo2}. The next equation's number was produced by the command \verb$\nydeqno$. Also, notice the use of \verb+\rem{or}+, which results in the text ``or'' without changing the alignment. To step the equation number counter, we want the following equations typeset in ordinary \texttt{eqnarray} environment: \begin{eqnarray} \tan ^2 \alpha & = & \frac{\sin ^2 \alpha}{\cos ^2 \alpha} \label{Demo3} \\ \tan \alpha & = & \frac{\sin \alpha}{\cos \alpha} \end{eqnarray} The upper equation was given the label \texttt{Demo3}. Now one of the ``recycling'' commands is to be demonstrated. First of all, let's make an ordinary reference to equation~\ref{Demo2}, and then ``recycle'' it: $$ \sin 2\alpha = 2 \sin \alpha \cos \alpha \reqno{Demo2} $$ This was obtained with \verb#$$ ... $$# with the command \verb#\reqno{Demo2}# at the end. Also partially numbered equations can be recycled with the \verb#\reqno{FOO}# command, as with equation~\ref{Demo1}: $$ \sin ( \alpha - \beta ) = \sin \alpha \cos \beta - \sin \beta \cos \alpha \reqno{Demo1} $$ (However, the use of \verb#\rndeqno{FOO}# and \verb#\rdeqno{FOO}# will produce strange results with two (different) partial equation numbers if \texttt{FOO} refers to a partially numbered equation.) The next equation was written with \verb#$$ ... $$# and a \verb#\deleqno# command at the end: $$ \tan 2\alpha = \frac{2\tan \alpha}{1 - \tan ^2 \alpha} \deleqno $$ Notice how the main equation number counter is still the same, despite that we now are outside of the \texttt{ddeqar} environment. Also, notice how the use of \verb#\reqno# above did not affect the equation number counter. The following equation is also set within \verb#$$ ... $$#, but it uses the command \verb#\nydeleqno# to produce an equation number with a new main number: $$ \sin ^2 \alpha = 1 - \cos ^2 \alpha \nydeleqno $$ Now we will elaborate a little on \verb#\rndeqno{FOO}# and \verb#\rdeqno{FOO}#. Let us use equation~\ref{Demo3}, and see what happens if we use the \verb#\rndeqno{FOO}# command: $$ \tan ^2 \alpha = \frac{\sin ^2 \alpha} {\cos ^2 \alpha} \rndeqno{Demo3} $$ which we rewrite: $$ \tan ^2 \alpha = \frac{\sin ^2 \alpha} {1 - \sin ^2 \alpha} \rdeqno{Demo3} \label{Demo4} $$ with \verb#\rdeqno{Demo3}# at the end. This is great fun, so why not one more: $$ \tan ^2 \alpha = \frac{1 - \cos ^2 \alpha} {\cos ^2 \alpha} \rdeqno{Demo3} $$ Also, the middle form of equation~\ref{Demo3} got a label, \texttt{Demo4}. There is still one equation to write. This time we again use the \texttt{deqarr} environment: \begin{deqarr} \cot \alpha & = & \frac{\cos \alpha}{\sin \alpha} \\ \where & = & \frac{1}{\tan \alpha} \end{deqarr} This example also shows the use of the \verb+\where+ command, which is a special case of the \verb+\rem+ command. Now, the interesting thing of referring to the recycled equations is ahead. If one writes \verb#\ref{Demo4}#, this is what \LaTeX\ will return:~\ref{Demo4}. That is not too instructive, since the partial equation numbers are quite common in this document. To make the complete reference, use \verb#\ref{Demo3}\ref{Demo4}#. The reference~\ref{Demo3}\ref{Demo4} is much more comprehensible, right? (If you get bad line-breaks at such references, put them in an \verb#\mbox{...}#.) Finally, the $\mathcal{END}$! If you want your equations left-aligned, just specify the \texttt{leqno} option for the \texttt{documentclass} you are using. It should work! If you have any suggestions, corrections or contributions, please contact me. Enjoy \LaTeX ! {\itshape mats d.} \end{document} \endinput %% %% End of file `delex.tex'.