@$i$:$k$ sends only on links in $L$
\\[0ex]$\,\equiv$$_{\mbox{\scriptsize def}}$$\;\;$$\forall$$e$:E. ($\uparrow$isrcv($e$)) $\Rightarrow$ (loc(sender($e$)) = $i$) $\Rightarrow$ (kind(sender($e$)) = $k$) $\Rightarrow$ (lnk($e$) $\in$ $L$)