[Tex/LaTex] Need tall QED symbol

Question

I need this tall QED symbol. Yes, need.

Here is an MWE, since my question was too short to meet quality standards.

\documentclass{article}
\usepackage{amssymb}

\begin{document}

\noindent In view of the choice we made for the orientation of $\partial D$, we conclude that 
\[\int_{\partial \mathbf{D}} \iota^*\omega = 
(-1)^n \int_{\mathbb{R}^{n-1}} a_n(\cdot,\cdot, \dots, \cdot, 0).\]
This completes the proof of the theorem. $\square$

\end{document}

Obviously the square should be replaced with the tall QED symbol. Thanks.

Answer 1

Here, I just scaled the \square in the vertical direction by a factor of 1.5 times the width, and called it \tallqed. The \smash prevents it from affecting line spacing. EDITED to reduce size. Note that first argument of \scalebox is the horizontal scaling, while 2nd (optional) argument is the vertical scaling. These can be adjusted to suit.

\documentclass{article}
\usepackage{amssymb,graphicx}
\def\tallqed{\smash{\scalebox{.75}[1.125]{$\square$}}}
\begin{document}

\noindent In view of the choice we made for the orientation of $\partial D$, we conclude that 
\[\int_{\partial \mathbf{D}} \iota^*\omega = 
(-1)^n \int_{\mathbb{R}^{n-1}} a_n(\cdot,\cdot, \dots, \cdot, 0).\]
This completes the proof of the theorem. \tallqed
\end{document}

WChargin correctly points out that the symbol stretch makes the box border thickness non-uniform on the sides compared with the top/bottom. If that is an issue, the problem can be remedied with a slightly altered definition, by \ooaligning two of the stretched \squares with a slight kern.

\documentclass{article}
\usepackage{amssymb,graphicx}
\def\tallqedX{\smash{\scalebox{.75}[1.125]{$\square$}}}
\def\tallqed{\ooalign{\tallqedX\cr\kern.2pt\tallqedX}}
\begin{document}

\noindent In view of the choice we made for the orientation of $\partial D$, we conclude that 
\[\int_{\partial \mathbf{D}} \iota^*\omega = 
(-1)^n \int_{\mathbb{R}^{n-1}} a_n(\cdot,\cdot, \dots, \cdot, 0).\]
This completes the proof of the theorem. \tallqed
\end{document}