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