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\begin{document}

\section{Grouping in multi-relations}
\[ a=b=c=d=e \]
\[ a=b,c=d   \]
\[ a=b,c,d,e \]
\[ a=b,c,d=e \]
\[ a=b>c\le d=e \]

\paragraph{But period is somewhat different!}
\[ a=b,c.d=e \]
\[ a=b.c,d=e \]


\section{Arrows as meta-relation}
\[ a=b \rightarrow c\le d=e \]
\[ a=b,c \rightarrow d=e \]
\[ a=b \leftrightarrow c\le d=e \]
\[ a=b,c \leftrightarrow d=e \]

\section{Other Meta relations}
\[ a (< e) \]
\[ a; (< e) \]
\[ a = b + c + d (< e) \]
\[ a = b + c + d \mod e \]
 
\end{document}
