# TeX code for inhibitory arrow

I know how to draw inhibitory arrow with tikzpicture package for diagrams, but I want to know how to type it in the text. For example think of a sentence

An inhibitory reaction is shown by $code$.

An inhibitory arrow is used in biology and is similar to \dashv, but it has a longer horizontal and a shorter vertical line (it should look like an arrow object). Another way of thinking about it is the \mapsto arrow in the opposite direction and without ">"-like ending.

## 2 Answers

I am really just following this answer.

\documentclass{article}
\DeclareFontFamily{U}{FdSymbolC}{}
\DeclareFontShape{U}{FdSymbolC}{m}{n}{<-> s * FdSymbolC-Book}{}
\DeclareSymbolFont{fdarrows}{U}{FdSymbolC}{m}{n}
\DeclareMathSymbol{\leftfootline}{\mathrel}{fdarrows}{"AC}
\DeclareMathSymbol{\rightfootline}{\mathrel}{fdarrows}{"AD}
\DeclareMathSymbol{\longleftfootline}{\mathrel}{fdarrows}{"C6}
\DeclareMathSymbol{\longrightfootline}{\mathrel}{fdarrows}{"C7}

\begin{document}
$A\leftfootline B$ $A\rightfootline B$ $A\longleftfootline B$ $A\longrightfootline B$
\end{document}


The question how to look up the code/coordinates for the symbol has been answered in this comment. Compile

\documentclass{article}
\usepackage{fdsymbol}
\usepackage{fonttable}
\begin{document}
\xfonttable{U}{FdSymbolC}{m}{n}
\end{document}


to get

To access the character, you can look up its hexadecimal "coordinates". The first one is on the right and the second one is the hexadecimal number of the entry. From this you see that \leftfootline is in the group with A and it is the 14th member of the group, so has "AC. This means we get it with

\DeclareMathSymbol{\leftfootline}{\mathrel}{fdarrows}{"AC}


The other entries are analogous.

With Computer Modern fonts you can use \mapsfromchar from St. Mary Road fonts.

\documentclass{article}
\usepackage{stmaryrd}

\newcommand{\inhib}{\relbar\mapsfromchar}

\begin{document}

$\inhib$ and $a\inhib b$

\end{document}