\documentclass[10pt, a4paper, oneside]{article}

\usepackage{extarrows}

\def\test#1/{%
	\texttt{\textbackslash #1:}\qquad& A\csname #1\endcsname[\text{to love}]{\text{we love}}Z}
\def\tfst #1/{%
	\texttt{\textbackslash #1:}\qquad& A\csname #1\endcsname[]{}Z}

\begin{document}
\section{Syntax}

\begin{verbatim}
\arrowname[sub-script]{super-script}
\end{verbatim}

\noindent
\texttt{arrowname} is \texttt{xlongequal}, \texttt{xLongleftarrow}, etc.

\noindent
The parameter \verb"[sub-script]" is optional.

\section{Examples}
\begin{align}
\test xlongequal/\\[5mm]
\test xLongleftarrow/\\
\test xLongrightarrow/\\
\test xLongleftrightarrow/\\
\test xLeftrightarrow/\\[3mm]
\test xlongleftrightarrow/\\
\test xlongrightarrow/\\[5mm]
\test xleftrightarrow/\\
\test xlongleftarrow/\\%[2mm]
(amsmath)\; \test xleftarrow/\\
(amsmath)\; \test xrightarrow/\\[3mm]
\tfst xlongleftarrow/\\
\tfst xlongrightarrow/\\
(amsmath)\; \tfst xleftarrow/\\
(amsmath)\; \tfst xrightarrow/
\end{align}
\end{document}
