\begin{tabbing}
Feasible($D$)
\\[0ex]$\,\equiv$$_{\mbox{\scriptsize def}}$$\;\;$\=($\forall$$i$:Id. Feasible(M($i$)))\+
\\[0ex]\& ($\forall$$l$:IdLnk, ${\it tg}$:Id. M(source($l$)).dout($l$,${\it tg}$) $\subseteq$r M(destination($l$)).din($l$,${\it tg}$))
\\[0ex]\& (\=$\forall$$i$:Id.\+
\\[0ex]finite{-}type(\{$l$:IdLnk$\mid$ destination($l$) = $i$ \& ($\uparrow$M(source($l$)) sends on link $l$)\} ))
\-\-
\end{tabbing}