$\forall$$l$:IdLnk, ${\it dt}$:${\it tg}$:Id fp$\rightarrow$ Type, ${\it tg}$:Id. rcv($l$,${\it tg}$) $\in$ dom(lnk{-}decl($l$;${\it dt}$)) $\sim$ ${\it tg}$ $\in$ dom(${\it dt}$)