\begin{circus}
\circchannel a \\
\circprocess P \circdef \circbegin \\
    \circspot (a \then \Skip) \lpar | \lchanset a \rchanset | \rpar ((a \then \Skip) \interleave (((a \then \Skip) \interleave (a \then \Skip)) \lpar | \lchanset a \rchanset | \rpar ((a \then \Skip) \interleave (a \then \Skip))))
\circend \\
\end{circus}