math-modesymbols
I've made little superscript plus and minus signs for something by defining
\newcommand{\minus}[1]{{#1}^{\scalebox{0.8}{-}}}
\newcommand{\plus}[1]{{#1}^{\scalebox{0.6}{\!+}}}
the problem is that compared to the plus, the minus looks really heavy. See for yourselves:
I think I'd rather have a heavier plus. Any thoughts? (other than that I should be less anal)
I am not too sure what font to use for the internal + and -, so I just used \hbox{\texttt{+}}. In TeX, each character has a \mathcode, describing its behavious in maths. All of them lie between "0000 and "7FFF (in hexadecimal), except the special mathcode "8000, which makes the character act like an active character. Within the group which \bra, \ket and \braket define, I get + and - to be active and expand to \braket@inner@minus and \braket@inner@plus.
\documentclass{article}
\usepackage{braket}
\makeatletter
\newcommand{\braket@inner@minus}{\hbox{\texttt{-}}}
\newcommand{\braket@inner@plus}{\hbox{\texttt{+}}}
\begingroup
\catcode`\-=13\relax %active
\catcode`\+=13\relax %active
\@firstofone{\endgroup %end the local changes to catcodes.
\newcommand\braket@inner@defs{%
\edef\restore@mathcode{%
\mathcode`\noexpand +=\the\mathcode`+%
\mathcode`\noexpand -=\the\mathcode`-%
}%
\mathcode`\+="8000\relax
\mathcode`\-="8000\relax
\def+{\begingroup\restore@mathcode\braket@inner@plus\endgroup}%
\def-{\begingroup\restore@mathcode\braket@inner@minus\endgroup}%
}%
}
% old definition:
% \newcommand{\bra}[1]{\mathinner {\langle {#1}|}}
% new definition:
\renewcommand{\bra}[1]{\mathinner {\langle \braket@inner@defs {#1}|}}
\renewcommand{\ket}[1]{\mathinner {|\braket@inner@defs{#1}\rangle }}
\renewcommand{\braket}[1]{\mathinner {\langle \braket@inner@defs {#1}\rangle }}
\makeatother
\begin{document}
\[
\bra{++--}A^\dag A\ket{-+-+} = \braket{++--|A^\dag A|-+-+} = \cdots
\]
However,
\[
\bra{++}(A+B)\ket{--} \neq \braket{++|(A+B)|--}
\]
\end{document}
I once proposed the following definitions
\newcommand\varpm{\mathbin{\vcenter{\hbox{%
\oalign{\hfil$\scriptstyle+$\hfil\cr
\noalign{\kern-.3ex}
$\scriptscriptstyle({-})$\cr}%
}}}}
\newcommand\varmp{\mathbin{\vcenter{\hbox{%
\oalign{$\scriptstyle({+})$\cr
\noalign{\kern-.3ex}
\hfil$\scriptscriptstyle-$\hfil\cr}%
}}}}
Example
\documentclass{article}
\newcommand\varpm{\mathbin{\vcenter{\hbox{%
\oalign{\hfil$\scriptstyle+$\hfil\cr
\noalign{\kern-.3ex}
$\scriptscriptstyle({-})$\cr}%
}}}}
\newcommand\varmp{\mathbin{\vcenter{\hbox{%
\oalign{$\scriptstyle({+})$\cr
\noalign{\kern-.3ex}
\hfil$\scriptscriptstyle-$\hfil\cr}%
}}}}
\begin{document}
$a\varpm b\varmp c$
\end{document}
Best Answer
You should use math mode not text mode with shrinking via the graphics driver.
This will make a minus sign not a hyphen, and be naturally smaller because of the superscript.