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$\forall$\=$E$, $X_{1}$, $X_{2}$: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), $e$:$E$, $l$:IdLnk.
\-\-\\[0ex]sends{-}bound($p$;$e$;$l$) $\in$ $E$
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