\begin{tabbing} $\forall$\=$D$:Dsys, ${\it sched}$:(Id$\rightarrow$($\mathbb{N}\rightarrow$(IdLnk+Id)+Unit)), $v$:($i$:Id$\rightarrow$M($i$).state),\+ \\[0ex]${\it dec}$:($j$,$b$:Id$\rightarrow$M($j$).state$\rightarrow$(M($j$).da(locl($b$))+Unit)). \-\\[0ex]Feasible($D$) \\[0ex]$\Rightarrow$ (\=$\forall$$i$:Id.\+ \\[0ex](\=$\forall$$l$:IdLnk.\+ \\[0ex]destination($l$) $=$ $i$ \\[0ex]$\Rightarrow$ M(source($l$)) sends on link $l$ \\[0ex]$\Rightarrow$ \=isl(${\it sched}$($i$))\+ \\[0ex]\& ($\forall$$t$:$\mathbb{N}$. $\exists$${\it t'}$:$\mathbb{N}$. $t$$\leq$${\it t'}$ \& isl(outl(${\it sched}$($i$))(${\it t'}$)) \& outl(outl(${\it sched}$($i$))(${\it t'}$)) $=$ $l$)) \-\-\\[0ex]\& (\=$\forall$$a$:Id.\+ \\[0ex]$a$ in dom(M($i$).pre) \\[0ex]$\Rightarrow$ \=isl(${\it sched}$($i$))\+ \\[0ex]\& (\=$\forall$$t$:$\mathbb{N}$.\+ \\[0ex]$\exists$${\it t'}$:$\mathbb{N}$. $t$$\leq$${\it t'}$ \& $\neg_{2}$isl(outl(${\it sched}$($i$))(${\it t'}$)) \& outr(outl(${\it sched}$($i$))(${\it t'}$)) $=$ $a$))) \-\-\-\-\\[0ex]$\Rightarrow$ FairFifo \end{tabbing}