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$\forall$\=$E$, $X_{1}$, $X_{2}$:Type, ${\it dE}$:EqDecider($E$), ${\it dL}$:EqDecider(IdLnk), ${\it info}$:($E$$\rightarrow$(Id$\times$$X_{1}$+(IdLnk$\times$$E$)$\times$$X_{2}$)), $e$,\+
\\[0ex]$r$:$E$, $l$:IdLnk. rcv{-}from{-}on(${\it dE}$;${\it dL}$;${\it info}$;$e$;$l$;$r$) $\in$ $\mathbb{B}$
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