Consider the following example:
\documentclass{article}
\usepackage{undertilde}
\begin{document}
$\utilde{x}$
\end{document}
Whenever I am trying to compile it with Kile, shows the error:
undertilde.sty not found.
I have trying to install it from ubuntu14.04(32bit) software centre by searching the name 'undertitle' but there are no such file. How can I solve this problem?