\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$)),\+
\\[0ex]$p$:(\=$\forall$$e$:$E$, $l$:IdLnk.\+
\\[0ex]$\exists$\=${\it e'}$:$E$\+
\\[0ex]($\forall$${\it e''}$:$E$. 
\\[0ex]($\uparrow$rcv?(${\it e''}$))
\\[0ex]$\Rightarrow$ (sender(${\it e''}$) = $e$)
\\[0ex]$\Rightarrow$ (link(${\it e''}$) = $l$)
\\[0ex]$\Rightarrow$ (((${\it e''}$ = ${\it e'}$) $\vee$ ${\it e''}$ $<$ ${\it e'}$) $\wedge$ (loc(${\it e'}$) = destination($l$) $\in$ Id)))),
\-\-\\[0ex]$r$:$E$.
\-\\[0ex]SWellFounded(pred!($e$;${\it e'}$))
\\[0ex]$\Rightarrow$ ($\forall$$e$:$E$. ($\neg$($\uparrow$first($e$))) $\Rightarrow$ (loc(pred($e$)) = loc($e$) $\in$ Id))
\\[0ex]$\Rightarrow$ ($\forall$$e$,${\it e'}$:$E$. (loc($e$) = loc(${\it e'}$) $\in$ Id) $\Rightarrow$ (${\it pred?}$($e$) = ${\it pred?}$(${\it e'}$)) $\Rightarrow$ ($e$ = ${\it e'}$))
\\[0ex]$\Rightarrow$ ($\uparrow$rcv?($r$))
\\[0ex]$\Rightarrow$ \=($r$ \+
\\[0ex]rel\_star($E$; ($\lambda$$x$,$y$. ($\neg$($\uparrow$first($y$))) c$\wedge$ ($x$ = pred($y$) $\in$ $E$))) sends{-}bound(\=$p$;\+
\\[0ex]sender($r$);
\\[0ex]link($r$)))
\-\-
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