\begin{tabbing} fpf($L$) \\[0ex]$\,\equiv$$_{\mbox{\scriptsize def}}$$\;\;$\=$\langle$remove{-}repeats(${\it eq}_{1}$;map($\lambda$$p$.1of($p$);$L$))\+ \\[0ex]$,\,$$\lambda$$x$.reduce($\lambda$$p$,$l$. if eqof(${\it eq}_{1}$)(1of($p$),$x$)$\rightarrow$ insert(2of($p$);$l$) else $l$ fi;nil;$L$)$\rangle$ \- \end{tabbing}