# Change (increase) the size of the arrowhead in \xleftarrow and \xrightarrow inside \begin{array}

I need to 'draw' a protocol flow using LaTeX. I decided to go with \begin{array}, since it is sufficient for my needs. However, the arrowhead in \xleftarrow and \xrightarrow is so small, that it is not very readable.

Is there a way to increase its size? Or at least change it to something bigger, which will be easy to see? Thank you.

\documentclass[extrafontsizes,10pt]{article}
\usepackage{amssymb}
\usepackage{amsfonts}
\usepackage{stmaryrd}
\usepackage{amsmath}

\begin{document}

$\begin{array}{c c c} \text{\textsf{C}} & & \text{\textsf{S}} \\ & \text{\scriptsize \texttt{REQUEST}} &\\ & \xrightarrow{\hspace{15em}\hspace{10em}} & \\ & \text{\scriptsize \texttt{RESPONSE}} & \\ & \xleftarrow{\hspace{15em}\hspace{10em}} & \\ \end{array}$

\end{document}

## 1 Answer

\documentclass[12pt]{article}
\usepackage{amssymb}
\usepackage{amsfonts}
\usepackage{stmaryrd}
\usepackage{amsmath}
\usepackage{tikz}

% add the following two lines to your document to get bigger arrows
\usetikzlibrary{arrows.meta}
\tikzset{>={Latex[width=3mm,length=3mm]}}

\begin{document}
$\begin{array}{c c c} \text{\textsf{C}} & & \text{\textsf{S}} \\ & \text{\scriptsize \texttt{REQUEST}} &\\ & \begin{tikzpicture} \draw[->] (0,0) node[left]{} -- (10,0) node[right]{}; \end{tikzpicture} & \\ & \text{\scriptsize \texttt{RESPONSE}} & \\ & \begin{tikzpicture} \draw[<-] (0,0) node[left]{} -- (10,0) node[right]{}; \end{tikzpicture} & \\ \end{array}$
\end{document}