% Dummy abbreviation to test relation symbols with parameters.
\begin{abbreviation}\label{abbr_equal}
    $x\EQUAL{y} z$ iff $x = z$.
\end{abbreviation}

\begin{proposition}\label{dummy_abbr_test}
    For all $x$ we have $x\EQUAL{y}x$.
\end{proposition}

% Dummy definition to test relation symbols with parameters.
\begin{abbreviation}\label{defn_equals}
    $x\EQUALS{y}{w} z$ iff $x = z$.
\end{abbreviation}

\begin{proposition}\label{dummy_defn_test}
    For all $x$ we have $x\EQUALS{y}{w}x$.
\end{proposition}