\begin{circus}
	\circchannel chan : \nat \cross \nat \cross \nat
\end{circus}

\begin{circus}
	\circchannel chan0 : \nat \cross \nat
\end{circus}

\begin{circus}
	\circchannel chan2 : \nat \cross \nat \cross \nat \cross \nat
\end{circus}

\begin{circus}
	\circprocess CCCC \circdef 
	\circbegin
\end{circus}
\begin{circusaction}
\circspot chan0?x?y \then \Skip
\end{circusaction}
\begin{circus}
\circend
\end{circus}