\begin{tabbing}
$M$.send($k$;$l$;$s$;$v$;${\it ms}$;$i$)
\\[0ex]$\,\equiv$$_{\mbox{\scriptsize def}}$$\;\;$\=$L$ != ($M$.2.2.2.2.2).1($<$$k$, $l$$>$)\+
\\[0ex]$\Rightarrow$
\\[0ex]${\it ms}$
\\[0ex]=
\\[0ex]if source($l$) = $i$ then concat(map($\lambda$${\it tgf}$.map($\lambda$$x$.$<$${\it tgf}$.1, $x$$>$;(${\it tgf}$.2)($s$,$v$));$L$)) else [] fi 
\-
\end{tabbing}