Is there a LaTeX command for the equal (=) sign? I'd like to overwrite the command so that all equal signs in my document are colored green. But it seems I cannot do it with just the symbol =, which is not a command.
[Tex/LaTex] LaTeX command for equal (=)
macrossymbols
Related Solutions
The amsmath package provides the \overset and \underset macros that can be used to place one symbol above or below another. If you want text above and below, you could use \DeclareMathOperator* (also from amsmath).
\documentclass{minimal}
\usepackage{amsmath}
\DeclareMathOperator*{\eq}{=}
\begin{document}
\begin{equation*}
\underset{b}{=} \quad \eq^a_b
\end{equation*}
\end{document}
There shouldn't be any problems using this in amsmath environments such as align.
\begin{align*}
A &\eq^b_a B \\
&\eq^b_a C
\end{align*}
However, if you use it in the middle column of an eqnarray or eqnarray* (which are generally considered to be obsolete), then you will need \displaystyle before \eq.
All of the above applies to egreg's suggestion of defining \eq via
\newcommand{\eq}[2]{\mathrel{\operatorname*{=}_#1^#2}}
which seems to improve the spacing (and may be better in other ways as well).
An option could be to use + and - in monospaced font:
\documentclass{article}
\def\Plus{\texttt{+}}
\def\Minus{\texttt{-}}
\begin{document}
\Plus 1\Minus 123\Minus 456\Minus 7890
\end{document}
Best Answer
Every character can be turned into a command in math mode, but some special tricks are needed.