\begin{circus}
	\circchannel a, b, c
\end{circus}

\begin{circus}
	\circprocess P1 \circdef \circbegin
\end{circus}

\begin{circusaction}
	\circspot
		a \then b \then c \then \Skip
\end{circusaction}

\begin{circus}	
	\circend
\end{circus}

\begin{circus}
	\circprocess P2 \circdef \circbegin
\end{circus}

\begin{circusaction}
	\circspot
		a \then b \then c \then \Skip
\end{circusaction}

\begin{circus}	
	\circend
\end{circus}

\begin{circus}
	\circprocess P3 \circdef \circbegin
\end{circus}

\begin{circusaction}
	\circspot
		a \then b \then c \then \Skip
\end{circusaction}

\begin{circus}	
	\circend
\end{circus}

\begin{circus}
	\circprocess P4 \circdef (P1 \interleave P2) \lpar \lchanset a \rchanset \rpar P3
\end{circus}
