# Positioning punctuation to the bottom right of an equation

You can always put the dot in the tikzpicture, making it sticks out without changing the bounding box with overlay:

\documentclass{article}

\usepackage{tikz}

\newcommand{\dummybox}{
\begin{tikzpicture}[baseline={([yshift=-0.45ex]current bounding box.center)}]
\draw (0,0) node[
fill=white,
rectangle,
draw,
minimum height=0.5in,
minimum width=1in] {};
\end{tikzpicture}
}

\newcommand{\dummyboxwithfullstop}{
\begin{tikzpicture}[baseline={([yshift=-0.45ex]current bounding box.center)}]
\draw (0,0) node[
fill=white,
rectangle,
draw,
minimum height=0.5in,
minimum width=1in] {};
\path[overlay] (current bounding box.south east) node{\qquad .};
\end{tikzpicture}
}

\begin{document}

$$\dummybox \quad = \quad \dummyboxwithfullstop$$

\end{document}


Personally, I find putting the period in line with the equation number to be more apparent than at the bottom. Also, I make every effort to not put punctuation in equations, but sometimes it is unavoidable.

That being said, you can use a subscript.

\documentclass{article}

\usepackage{tikz}

\newcommand{\dummybox}{
\begin{tikzpicture}[baseline={([yshift=-0.45ex]current bounding box.center)}]
\draw (0,0) node[
fill=white,
rectangle,
draw,
minimum height=0.5in,
minimum width=1in] {};
\end{tikzpicture}
}

\begin{document}

$$\left. \dummybox \quad = \quad \dummybox \quad\right._{\displaystyle .}$$

\end{document}