# How to specify theorem styles (amsthm) should use bold equations (bm)?

From other questions on this site, I've come to the conclusion that bm is the easiest (best?) way to get bold equations.

I'm using amsthm to define a problem style, but the \bfseries doesn't make the equations bold, and adding \bm to the body font specification doesn't do it either. I'd like a way to specify that equations in the problem style should be bold so I don't have to wrap it around every little equation.

\documentclass[11pt,letterpaper]{article}

\usepackage{amsthm}
\usepackage{bm}

\newtheoremstyle{parenbold} % Name
{2\parskip}           % Space above
{}                    % Space below
{\itshape \bfseries}  % Body font
{}                    % Indent amount
{}                    % Punctuation after theorem head
{1em}                 % Space after theorem head
{\thmname{#1 }\thmnumber{#2)}\thmnote{ [#3]}} % Theorem head spec

\theoremstyle{parenbold}
\newtheorem{prob}{Problem}
\newtheorem{probpart}{}
\renewcommand*{\theprobpart}{\alph{probpart}}

\begin{document}

\begin{prob}
$\bm{H}$ and $\bm{K}$ are two subgroups of $\bm{G}$ of order $\bm{m}$ and $\bm{n}$ respectively.  Prove...
\end{prob}

\end{document}

• Italics already give emphasis; boldface adds another level of emphasis. Too much like a punch in the eye, in my opinion. – egreg Oct 5 '15 at 8:17
• Yes, I figured someone would mention that. ;) I've been playing around with it, regularly making changes. Italics on its own is barely distinguishable from regular text to my eye. Perhaps I just make everything simply bold, but then the thm body and thm head are identical, which isn't really what I want either. Bold by itself also looks too strong (brutish), and to my eye, bold italics (graceful) uses "less ink" and so gives an emphasis between bold and normal. Fortunately I know how to make these changes on my own and can keep trying to tweak it until I find something that works best. – Travis Bemrose Oct 5 '15 at 14:11

bm is for bold expressions in an otherwise normal weight math. To make all the math bold you should use \boldmath outside the math. So here you could use
 {\itshape \bfseries\boldmath}

• Thanks, that works great. I don't quite follow your explanation though. What does "in an otherwise normal weight math" mean, and how is this different from \boldmath? – Travis Bemrose Oct 5 '15 at 13:50
• @TravisBemrose \boldmath $a=b$ makes a bold a=b, bm is intended for $a=\bm{b}$ making a bold b in a math expression that is otherwise non-bold. – David Carlisle Oct 5 '15 at 16:04