\begin{tabbing}
es{-}trans{-}state{-}from\=\{i:l\}\+
\\[0ex](${\it es}$; ${\it ks}$; $g$; $z$; $e_{1}$; $e_{2}$)
\-\\[0ex]$\,\equiv$$_{\mbox{\scriptsize def}}$$\;\;$list\_accum(\=$x$,$a$.spreadn(\=$a$;\+\+
\\[0ex]$k$,$s$,$v$.if deq{-}member(Kind{-}deq; $k$; ${\it ks}$)
\\[0ex]then $g$($k$,$s$,$v$,$x$)
\\[0ex]else $x$
\\[0ex]fi );
\-\\[0ex]$z$;
\\[0ex]es{-}hist\=\{i:l\}\+
\\[0ex](${\it es}$; $e_{1}$; $e_{2}$))
\-\-
\end{tabbing}