Curly braces with subscript and superscript

Question

I'm looking for a way to write something like this:

\lbrace A_i\rbrace _{i = 1}^{n}

My goal is to put a subscript and a superscript near the right curly brace. How can I do it? The subscript and the superscript should be below and above the ends of the right curly brace.

Answer 1

The subscript and the superscript should be below and [above] the ends of the right curly brace.

Something like this?

\documentclass{article}
\usepackage{amsmath} % for "\overunderset" macro
\begin{document}
$
\overunderset{n}{i=1}{\rbrace}     \quad
\overunderset{n}{i=1}{\big\rbrace} \quad
\overunderset{n}{i=1}{\Big\rbrace} \quad
\overunderset{n}{i=1}{\bigg\rbrace}\quad
\overunderset{n}{i=1}{\Bigg\rbrace}
$
\end{document}

Answer 2

Using another approach with \mathop,

\documentclass[a4paper,12pt]{article}
\usepackage{amsmath}
\begin{document}
$\mathop{\}}\limits_{i=1}^{n}$,
$\mathop{\bigr\}}\limits_{i=1}^{n}$,
$\mathop{\biggr\}}\limits_{i=1}^{n}$,
$\mathop{\Bigr\}}\limits_{i=1}^{n}$,
$\mathop{\Biggr\}}\limits_{i=1}^{n}$
\end{document}

Answer 3

One needs to declare the object as a closing delimiter.

\documentclass{article}
\usepackage{amsmath}

\NewDocumentCommand{\rbracex}{O{}e{^_}}{%
  \mathclose{%
    \IfNoValueTF{#2}{% #2 is the possible superscript
      \underset{#2}{#1\rbrace}%
    }{%
      \IfNoValueTF{#3}{% #3 is the possible subscript
        \overset{#2}{#1\rbrace}%
      }{%
        \overunderset{#2}{#3}{#1\rbrace}%
      }%
    }%
  }% matching \mathclose
}

\begin{document}

\[
\lbrace A\rbracex_{i=1}^n
\quad
\big\lbrace A\rbracex[\big]_{i=1}^n
\quad
\Big\lbrace A\rbracex[\Big]_{i=1}^n
\]

\end{document}

I'd avoid this notation with great care.

A possible improvement, prompted by comments by barbara beeton:

\documentclass{article}
\usepackage{amsmath}

\NewDocumentCommand{\rbracex}{O{}e{^_}}{%
  \mathclose{%
    % let's compute the amount of backing up
    \sbox0{\mathsurround=0pt$#1\rbrace$}%
    \sbox2{\mathsurround=0pt
      $\IfNoValueTF{#2}{% #2 is the possible superscript
        \underset{#2}{#1\rbrace}%
      }{%
        \IfNoValueTF{#3}{% #3 is the possible subscript
          \overset{#2}{#1\rbrace}%
        }{%
          \overunderset{#2}{#3}{#1\rbrace}%
        }%
      }$%
    }% end of \sbox2
   \ifdim\wd0>\wd2
     % do nothing
   \else
     \kern\dimexpr(\wd0-\wd2)/2\relax
   \fi
   \usebox{2}%
  }% matching \mathclose
}

\begin{document}

\[
\lbrace A_i\rbracex_{i=1}^n
\quad
\big\lbrace A_i\rbracex[\big]_{i=1}^n
\quad
\Big\lbrace A_i\rbracex[\Big]_{i=1}^n
\]

\end{document}

Well, not really an improvement, I'm afraid.