\begin{tabbing}
$\forall$$i$:top, $L$:(top List).
\\[0ex]sqequal(\=R{-}da(Rlist($L$); $i$);\+
\\[0ex]reduce(($\lambda$$u$,${\it da}$. fpf{-}join(Kind{-}deq; R{-}da($u$; $i$); ${\it da}$)); fpf{-}empty; $L$))
\-
\end{tabbing}