$\forall$$p$, $q$:(IdLnk List), $i$, $j$, $k$:Id.
\\[0ex]lconnects($p$;$i$;$j$) $\Rightarrow$ lconnects($q$;$j$;$k$) $\Rightarrow$ ($\exists$$r$:IdLnk List. lconnects($r$;$i$;$k$))