\begin{tabbing}
interface{-}link($A$;$B$;$l$;${\it tg}$)
\\[0ex]$\,\equiv$$_{\mbox{\scriptsize def}}$$\;\;$\=rcv($l$,${\it tg}$) declared in $A$(source($l$))\+
\\[0ex]\& rcv($l$,${\it tg}$) declared in $B$(destination($l$))
\\[0ex]\& ($\neg$rcv($l$,${\it tg}$) declared in $B$(source($l$)))
\-
\end{tabbing}