vertical equal sign

Question

I am looking to create a vertical equal sign that might function similarly to an underbrace. I often use this symbol when taking notes on paper.

 (x+z) + (y+d) = 10
  ||      || 
  5       5

The alignment is not entirely perfect in this example but I believe the idea comes across.

Answer 1

Here is another way of achieving this. You use the command \equalto{equation}{value}.

\documentclass{scrartcl}  

\usepackage{mathtools}

\newcommand{\verteq}{\rotatebox{90}{$\,=$}}
\newcommand{\equalto}[2]{\underset{\scriptstyle\overset{\mkern4mu\verteq}{#2}}{#1}}

\begin{document}

\[
    \equalto{(x + z)}{5} + \equalto{(y + d)}{5} = 10
\]

\end{document}

And this is the output:

As you can see, I added some spacing to the vertical equal manually (and some horizontal spacing to the \equalto command), of course, you can tweak both to get the exact output you want.