%% 
%%  Ein Beispiel der DANTE-Edition
%%  Mathematiksatz mit LaTeX
%%  3. Auflage
%%  Beispiel 07-04-7 auf Seite 141.
%%  Copyright (C) 2018 Herbert Voss
%% 
%%  It may be distributed and/or modified under the conditions
%%  of the LaTeX Project Public License, either version 1.3
%%  of this license or (at your option) any later version.
%%  See http://www.latex-project.org/lppl.txt for details.
%% 
%% ==== 
% Show page(s) 1
%% 
%% 
\documentclass[10pt]{examinimal-mathsymbols}
\pagestyle{empty}
\setlength\textwidth{352.81416pt}
%StartShownPreambleCommands
\usepackage{array,mathabx}
%StopShownPreambleCommands
\begin{document}
\renewcommand\arraystretch{1.1}
\begin{tabular}{@{}*{2}{r@{\kern3pt}l}r@{\kern3pt}l@{}l@{}}
\mathsymbol{nLeftarrow}            \mathsymbol{nleftrightarrow}    \mathsymbol{nrightarrow} \\
\mathsymbol{nleftarrow}            \mathsymbol{nLeftrightarrow}    \mathsymbol{nRightarrow}\\
\mathsymbol{barleftharpoon}   \mathsymbol{leftharpoonup}     \mathsymbol{rightleftharpoons}   \\
\mathsymbol{barrightharpoon}  \mathsymbol{leftleftharpoons}  \mathsymbol{rightrightharpoons} \\
\mathsymbol{downdownharpoons} \mathsymbol{leftrightharpoon}  \mathsymbol{updownharpoons}   \\
\mathsymbol{downharpoonleft}  \mathsymbol{leftrightharpoons} \mathsymbol{upharpoonleft}     \\
\mathsymbol{downharpoonright} \mathsymbol{rightbarharpoon}   \mathsymbol{upharpoonright}   \\
\mathsymbol{downupharpoons}   \mathsymbol{rightharpoondown}  \mathsymbol{upupharpoons}   \\
\mathsymbol{leftbarharpoon}   \mathsymbol{rightharpoonup}    \mathsymbol{leftharpoondown}  \\
\mathsymbol{rightleftharpoon}
\end{tabular}
\end{document}