# Underbar nabla symbol doesn't work

I want to write a symbol like the one shown in the following image

but I can't make it work. I tried:

$$\underbar{\nabla}$$


but it didn't work (I think the reason for this is that the input for the underbar command should be only text.

How can I make this work ?

• Why are you using the text-mode command \underbar instead of the math-mode command \underline? – Mico Jun 21 at 3:30
• I wasn't aware of that command :D. Now, I know. – Andreas Mastronikolis Jun 21 at 9:07

\documentclass{article}

\begin{document}

$\underline{\nabla}$
\end{document}

\documentclass{article}
\usepackage{amsmath}

\begin{document}

$\underbar{\hbox{$\nabla$}}$
\end{document}


or, alternately,

\documentclass{article}
\usepackage{amsmath}

\begin{document}

$\setbox0=\hbox{$\nabla$}\underbar{\box0}$
\end{document}


• Thanks! Will accept the answer when I can (apparently it needs some time) – Andreas Mastronikolis Jun 20 at 18:08
• the system forces you to wait to allow time for, hmm, better answers:-) – David Carlisle Jun 20 at 18:13
• @DavidCarlisle Answers, schmansers. – Steven B. Segletes Jun 20 at 18:14
• \underline is the primitive (and math mode), \underbar is a latex text mode version defined essentially as \def\hbar#1{\underline{\hbox{#1}} so nesting that in another hbox layer and another math group to get back to math mode is not the most direct route. – David Carlisle Jun 20 at 18:18
• @DavidCarlisle My sarchasm was purely in jest. If you post, the answer is almost assuredly better than mine, and always for good reason. – Steven B. Segletes Jun 20 at 18:19