# Issue with bm and breqn packages - is there a way to use a package in only part of a document?

I am a long time stack exchange reader. I always found useful information here. This is however my first post.

I have a little issue that I am working on that maybe someone can provide a quicker fix.

I have a TeX document with hundreds of equations. Most of which use the bm package. I also have many equations that are several lines long. These were generated with Maple and have many \left \right commands in them. As a result, the package \usepackage{breqn} works very well in organizing them.

It is a known issue that the bm package and the breqn package cause each other much pain.

My issue is that I would like to use the \usepackage{breqn} in part of my document and then not use it in another part of the document. Is this possible?

Thank you!

%\documentclass{article}
\documentclass[12pt]{asme2ej}
\usepackage{amsmath}    % need for subequations
\usepackage{graphicx}   % need for figures
\usepackage{verbatim}   % useful for program listings
\usepackage{color}      % use if color is used in text
\usepackage{subfigure}  % use for side-by-side figures
\usepackage{hyperref}   % use for hypertext links, including those to external documents and URLs
\usepackage{fixltx2e}
\usepackage{multirow} % for tables (multirow tables)
\usepackage{cite}    % to group lots of citations
\usepackage{paralist}  \setdefaultitem{}{\textbullet}{$\star$}{}% formats for some list styles
\usepackage{setspace}   % for double space command

\usepackage{breqn}     % break equation line automatically  ******* this packages does not like the \bm package *******
\usepackage{bm}

\begin{document}

\begin{dmath}
- \bm c \left( \cos \left( \theta \right) {\theta_{{d}}}^{2}+\theta_{{{\it
dd}}}\sin \left( \theta \right)  \right) -l_{{{\it rdd}}}\sin \left(
\mu \right) \cos \left( \gamma \right) -2\,l_{{{\it rd}}} \left( -\sin
\left( \mu \right) \sin \left( \gamma \right) \gamma_{{d}}+\cos
\left( \gamma \right) \cos \left( \mu \right) \mu_{{d}} \right) -l_{{
r}} \left( -\gamma_{{{\it dd}}}\sin \left( \gamma \right) \sin \left(
\mu \right) -\gamma_{{d}} \left( \cos \left( \mu \right) \sin \left(
\gamma \right) \mu_{{d}}+\sin \left( \mu \right) \cos \left( \gamma
\right) \gamma_{{d}} \right) +\mu_{{{\it dd}}}\cos \left( \gamma
\right) \cos \left( \mu \right) +\mu_{{d}} \left( -\sin \left( \gamma
\right) \cos \left( \mu \right) \gamma_{{d}}-\cos \left( \gamma
\right) \sin \left( \mu \right) \mu_{{d}} \right)  \right) =x_{{{\it
dd}}}
\end{dmath}

\end{document}

-
Welcome to TeX.SX! No, you can't disable breqn. See tex.stackexchange.com/questions/100262/… –  egreg Nov 22 '13 at 22:31
Thanks egreg! It seems my alternative is to use \mathbf x instead of \bm x. –  FeX Nov 22 '13 at 22:35
I get no error. What TeX distribution are you using? –  egreg Nov 22 '13 at 22:48
Avoid the MacPorts TeX Live. You can configure Kile to use the MacTeX distribution, just change the paths to use /usr/texbin/pdflatex and similar. –  egreg Nov 22 '13 at 22:55
The example in the question runs without error in texlive 2013 and produces a bold c and breaks the equation over 5 lines. –  David Carlisle Nov 22 '13 at 23:23

With an up-to-date TeX distribution the file runs fine with the article class. With asme2ej it doesn't, but for a very simple reason: the class does

\RequirePackage{times}
\RequirePackage{mathptm}


The times and mathptm packages have been obsolete for at least eight years (probably more; the current version of mathptmx was released in 2005).

The correct call should be

\RequirePackage{mathptmx}


but this wouldn't solve the problem either. In order to have a chance to work, the bm package needs bold versions of the math fonts, which mathptmx doesn't provide. In this case bm resorts to doing “poor man's bold”, which breaks breqn.

You'll be luckier if you load

\usepackage{newtxtext,newtxmath}


in your document. The math fonts are slightly different (but better) than those obtained with mathptmx.

A comment. While I can understand your need to rely on Maple output because of the great number of equation, I believe that writing mathematics is not simply jotting down long formulas in a way that the reader can't follow without rewriting them. The output I get from your example is simply unreadable.

There are too many useless parentheses: writing “sin(x)” instead of the customary “sin x” is distracting. The constants that multiply the sines and cosines are sometimes at the left and sometimes at the right without apparent reasons. Only two parentheses are made bigger (because of wrong usage of \left and \right); the unique exponent is placed wrongly.

-
egreg, thank you very much for your answer and time. I also agree with you about the portrayal of the mathematics. I have decided to manually go through each equation and make sure they are properly portrayed. I have many many relations much more complicated than the above, however for me it is worth the extra effort. –  FeX Nov 23 '13 at 17:27
I do find it odd that a reputable algebraic manipulator engine would then convert TeX equations slightly wrongly. Interesting. –  FeX Nov 23 '13 at 17:29
@FeX Unfortunately, it seems that who programmed the translation didn't know TeX very well. –  egreg Nov 23 '13 at 17:30
Yes, it does seem that way. Thanks again :) –  FeX Nov 23 '13 at 17:36