\begin{tabbing} $\forall$\=$E$, $X_{1}$, $X_{2}$:Type, ${\it info}$:($E$$\rightarrow$(Id$\times$$X_{1}$+(IdLnk$\times$$E$)$\times$$X_{2}$)), ${\it pred?}$:($E$$\rightarrow$($E$+Unit)),\+ \\[0ex]$p$:(\=$\forall$$e$:$E$, $l$:IdLnk.\+ \\[0ex]$\exists$${\it e'}$:$E$. \\[0ex]$\forall$${\it e''}$:$E$. \\[0ex]rcv?(${\it e''}$) \\[0ex]$\Rightarrow$ sender(${\it e''}$) $=$ $e$ \\[0ex]$\Rightarrow$ link(${\it e''}$) $=$ $l$ \\[0ex]$\Rightarrow$ ${\it e''}$ $=$ ${\it e'}$ $\vee$ ${\it e''}$ $<$ ${\it e'}$ \& loc(${\it e'}$) $=$ destination($l$) $\in$ Id), $r$:$E$. \-\-\\[0ex]SWellFounded(pred!($e$;${\it e'}$)) \\[0ex]$\Rightarrow$ ($\forall$$e$:$E$. $\neg$first($e$) $\Rightarrow$ loc(pred($e$)) $=$ loc($e$) $\in$ Id) \\[0ex]$\Rightarrow$ ($\forall$$e$, ${\it e'}$:$E$. loc($e$) $=$ loc(${\it e'}$) $\in$ Id $\Rightarrow$ ${\it pred?}$($e$) $=$ ${\it pred?}$(${\it e'}$) $\Rightarrow$ $e$ $=$ ${\it e'}$) \\[0ex]$\Rightarrow$ rcv?($r$) \\[0ex]$\Rightarrow$ ($r$ (($\lambda$$x$,$y$. $\neg$first($y$) \& $x$ $=$ pred($y$) $\in$ $E$)$^{\mbox{\scriptsize $\ast$}}$) sends{-}bound($p$;sender($r$);link($r$))) \end{tabbing}