# Make Underbrace ignore Brackets

I am using under brace to define an important term. The code I'm using generates the following:

Code:

h_n\left[f_X(0)\underbrace{\int_0^{+\infty}K(z)^2dz}_{\equiv\beta} +o_p(1)\right]


There is one problem, the brackets extend to allow the beta to fit inside it. I would like to avoid this behavior: brackets extend only enough to fit the integral, but not to fit the underbrace. Instead, I would like to obtain the following:

Is it possible? How can I generate such outcome?

Thanks for helping! :D

\documentclass{article}

\begin{document}
$$h_n\biggl[f_X(0)\underbrace{\int_0^{+\infty}K(z)^2dz}_{\equiv\beta} +o_p(1)\biggr]$$
\end{document}

• It's better to avoid the automatic delimiters anyway. Have a look at the mathtools package for better-spaced ones. – JPi Nov 11 '16 at 2:54

I am not advocating this solution, but onw way to solve this issue and still allow for "automatic" resizing is to use \smash and an appopriate \vphantom:

## Code:

\documentclass{article}

\begin{document}
$$h_n\left[f_X(0)\vphantom{\int}\smash{\underbrace{\int_0^{+\infty}K(z)^2dz}}_{\equiv\beta} +o_p(1)\right]$$
\end{document}

• One problem. When using smash inside align with multiple lines, then the next line will collide with the smashed underbrace. – mxmlnkn Apr 2 '18 at 18:42
• @mxmlnkn: You can use the optinal parameter to \\  to add some vertical space. For instance, you can use \\\[1.0ex] to increase the space between the current line and the subsequent line. – Peter Grill Apr 4 '18 at 21:25