A strange symbol

In the Lathi-Ding's book on communication systems, there is a strange wavy overbar as it is shown in the attached figure ... how can i use it in LaTEX?

• This suggests the creation of a package olem (cf. ulem). Jun 1, 2018 at 20:28

You can use the \lfilet growing delimiter of mathabx, sized to the width of the material and rotated.

\documentclass{article}
\usepackage{graphicx}

\DeclareFontFamily{U}{mathx}{}
\DeclareFontSubstitution{U}{mathx}{m}{n}
\DeclareFontShape{U}{mathx}{m}{n}{ <-> s*[0.6]mathx10 }{}
\DeclareSymbolFont{mathx}{U}{mathx}{m}{n}
\DeclareMathDelimiter{\lfilet}{4}{mathx}{"37}{mathx}{"37}

\makeatletter
\DeclareRobustCommand{\overfilet}[1]{{%
\mathpalette\over@filet{#1}%
}}
\newcommand{\over@filet}[2]{%
\sbox\z@{$\m@th#1#2\vphantom{^1}$}%
\sbox\tw@{$\m@th #1\left\lfilet\vbox to 0.55\wd\z@{}\right. \kern-\nulldelimiterspace$}%
\vbox{\ialign{\hfil##\hfil\cr
\rotatebox[origin=c]{90}{\box\tw@}\cr
\noalign{\nointerlineskip}
\box\z@\cr
}}%
}
\makeatother

\begin{document}

$P_g = \overfilet{g^2(t)} + \overfilet{g(t)g(t\pm\tau)}$

\end{document}


With s*[0.4]mathx10 instead of 0.6, the output would be

• Amazing. The 0.4 option looks better to me. Jun 1, 2018 at 20:40