# How to write the L-shaped symbol in latex?

I want to write the following equation in latex but dunno what's that L-shaped symbol.

I tried "\llcorner", but this is not what I exactly want... It looks like the following image:

I also tried Mathpix and read the great, big list of latex symbols, but couldn't find it. So, any help is definitely appreciated.

It could be built from \rules.

\documentclass{article}
\usepackage{mathtools}
\usepackage[scr=boondoxupr]{mathalpha}
\newcommand*{\Lcorner}{%
\mathchoice%
{\mathrel{\makebox[7pt][c]{\rule{.4pt}{7.5pt}\rule{5pt}{.4pt}}}}%
{\mathrel{\makebox[7pt][c]{\rule{.4pt}{7.5pt}\rule{5pt}{.4pt}}}}%
{\mathrel{\makebox[5.5pt][c]{\rule{.4pt}{5.25pt}\rule{3.5pt}{.4pt}}}}%
{\mathrel{\makebox[4pt][c]{\rule{.4pt}{3.75pt}\rule{2.5pt}{.4pt}}}}%
}
\DeclareMathOperator{\Tan}{Tan}

\begin{document}
$$\displaystyle \Lcorner$$
$$\textstyle \Lcorner$$
$$\scriptstyle \Lcorner$$
$$\scriptscriptstyle \Lcorner$$

$$\displaystyle \Tan^k( \mathscr{H}^k \Lcorner F(E), y ) = DF(x)[\Tan^k( \mathscr{H}^k \Lcorner E, x)]$$

$$\textstyle \Tan^k( \mathscr{H}^k \Lcorner F(E), y ) = DF(x)[\Tan^k( \mathscr{H}^k \Lcorner E, x)]$$

$$\scriptstyle \Tan^k( \mathscr{H}^k \Lcorner F(E), y ) = DF(x)[\Tan^k( \mathscr{H}^k \Lcorner E, x)]$$

$$\scriptscriptstyle \Tan^k( \mathscr{H}^k \Lcorner F(E), y ) = DF(x)[\Tan^k( \mathscr{H}^k \Lcorner E, x)]$$
\end{document}

• Thank you so much for this complete guide. Really appreciate it. – Zeno cosini Jun 5 '20 at 15:58

The symbol is \rightangle, and is in unicode-math or the legacy packages stix, stix2, mathdesign, fdsymbol, and a few others.

• I couldn't get it to work with unicode-math alone. It was present only in fdsymbol. The OPs symbol is slightly taller that it is wide. fdsymbol \right angle looked as tall as it was wide. – AJN Jun 6 '20 at 7:17
• @AJN Which version of unicode-math? It’s definitely in 0.8q. – Davislor Jun 6 '20 at 7:19
• V 0.81 I think. But I now notice that unicode-math is for lualatex and zelatex engines. – AJN Jun 6 '20 at 7:22
• @AJN Ah! That’d explain it. – Davislor Jun 6 '20 at 7:56

Picture mode to the rescue. The symbol correctly changes size in the various math styles as well as in different font sizes.

\documentclass{article}
\usepackage{amsmath,pict2e,mathrsfs}

\makeatletter
\DeclareRobustCommand{\Lcorner}{\mathbin{\mspace{1mu}\text{\L@corner}\mspace{1mu}}}
\newcommand{\L@corner}{%
\setlength{\unitlength}{\fontcharht\fontT}%
\begin{picture}(0.8,1)
\roundcap
\Line(0,1)(0,0)(0.8,0)
\end{picture}%
}
\makeatother

\DeclareMathOperator{\Tan}{Tan}

\begin{document}

$$\displaystyle \Lcorner$$
$$\textstyle \Lcorner$$
$$\scriptstyle \Lcorner$$
$$\scriptscriptstyle \Lcorner$$

$$\displaystyle \Tan^k( \mathscr{H}^k \Lcorner F(E), y ) = DF(x)[\Tan^k( \mathscr{H}^k \Lcorner E, x)]$$

$$\textstyle \Tan^k( \mathscr{H}^k \Lcorner F(E), y ) = DF(x)[\Tan^k( \mathscr{H}^k \Lcorner E, x)]$$

$$\scriptstyle \Tan^k( \mathscr{H}^k \Lcorner F(E), y ) = DF(x)[\Tan^k( \mathscr{H}^k \Lcorner E, x)]$$

$$\scriptscriptstyle \Tan^k( \mathscr{H}^k \Lcorner F(E), y ) = DF(x)[\Tan^k( \mathscr{H}^k \Lcorner E, x)]$$

{\Large $A\Lcorner B$} {\footnotesize $A\Lcorner B$}
\end{document}
`

I reused the code by Vincent.