Superscript in subscript (notation for removing one row and column from a matrix)

Question

I need some notation for a matrix M which indicates that row r and column c is excluded. I tried

M_{(r,c)^-}

but the minus sign is too low and not close enough for this to be good notation.

\documentclass{article}
\usepackage{amsmath}

\begin{document}

\[
M_{(r,c)^-}
\]

\end{document}

Here are some proposals which I don't know how to do in LaTeX:

• Move the minus sign to be a little higher and closer to the close bracket and maybe a little smaller.
• Forget the minus sign but use a bracket which is not (), [] or {}.

Answer 1

There are various ways to modify the position of the superscript. From {(x+y)}^2 or (x+y)^2?, Horizontal placement of subscript/superscript, How to raise a subscript?:

\documentclass{article}

\begin{document}
$M_{(r,c)^-}$
$M_{{(r,c)}^-}$       % lowers the subscript
$M_{{(r,c)}^{\!-}}$   % horizontal position
$M_{(r,c)}${\raisebox{0.5pt}{${}^{\!\!\!-}$}}  % vertical position
\end{document}