\begin{tabbing}
lconnects($p$;$i$;$j$)
\\[0ex]$\,\equiv$$_{\mbox{\scriptsize def}}$$\;\;$\=lpath($p$)\+
\\[0ex]\& ($\parallel$$p$$\parallel$ $=$ 0 $\Rightarrow$ $i$ $=$ $j$)
\\[0ex]\& ($\neg\parallel$$p$$\parallel$ $=$ 0 $\Rightarrow$ $i$ $=$ source(hd($p$)) \& $j$ $=$ destination(last($p$)))
\-
\end{tabbing}