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ecl{-}m3($a$; ${\it snd}$; $x$; $l$)($k$)
\\[0ex]$\,\equiv$$_{\mbox{\scriptsize def}}$$\;\;$let $g$\= = fpf{-}cap(${\it snd}$; product{-}deq(Knd; IdLnk; Kind{-}deq; idlnk{-}deq); $<$$k$, $l$$>$; []) in\+
\\[0ex]map(\=($\lambda$${\it tr}$.spreadn(\=${\it tr}$;\+\+
\\[0ex]${\it tg}$,$n$,$f$.$<$${\it tg}$, $\lambda$$s$,$v$. if $a$($n$,$k$,$s$,$v$,$s$($x$)) then $f$($s$,$v$) else [] fi $>$
\\[0ex]));
\-\\[0ex]fpf{-}cap(${\it snd}$; product{-}deq(Knd; IdLnk; Kind{-}deq; idlnk{-}deq); $<$$k$, $l$$>$; []))
\-\-
\end{tabbing}