It seems that using \boldmath (or \bm) along with the \not does not quite work so well. Here is an example using \not\subseteq and \not\le
where the line representing negation does not stretch sufficiently past the end of the symbol.

Questions:
Is there a better way to get bold math, or do I need to resort to my usual overkill solution and use
\tikzto draw thenotline?Is this is known issue with bold math, and are there other known issues with bold math?
References:
- I am using the solution from Colored symbols for
\MathColor, the math equivalent for\textcolor. - Followup question: Automate replacement of `\not` when in `\bm` mode.
Code:
\documentclass{article}
\usepackage{bm}
\usepackage{xcolor}
%% https://tex.stackexchange.com/questions/85033/colored-symbols-in-latex
\newcommand{\MathColor}{}
\def\MathColor#1#{\mathcoloraux{#1}}
\newcommand{\mathcoloraux}[3]{%
\protect\leavevmode
\begingroup
\color#1{#2}#3%
\endgroup
}
\newcommand{\Expression}{R \not\subseteq T, x \not\le y}%
\begin{document}
\begin{tabular}{r l}
& $\Expression$ \% This works fine.
\verb|\boldmath|: & {\boldmath $ \Expression$} \
\verb|\bm|: & \bm{$\Expression$}
\end{tabular}
\bigskip
Test with color
\medskip
\begin{tabular}{r l}
\verb|\MathColor|: & $\MathColor{red}{\Expression}$ \
\verb|\boldmath|: & {\boldmath $ \MathColor{red}{\Expression}$} \
\verb|\bm|: & %\par\bm{$\MathColor{\Expression}$}%% ???
\end{tabular}
\end{document}

\notdoes not extend that much over the negated symbol, but other than that … Sadly, the\nsubseteqmacro from theamssymbpackage behaves much worse. The\bm-\Mathcolorcombination works again if you add another set of{ }braces around\MathColor(potentially harming the spacing, again):\bm{${\MathColor{red}{\Expression}}$}– Qrrbrbirlbel Feb 16 '13 at 04:44\not\le. – Peter Grill Feb 16 '13 at 05:03coloraround here. :-) But he does have an unfair advantage. – Peter Grill Feb 16 '13 at 05:05