\begin{tabbing} $\forall$\=$E$,$T$,$X_{1}$,$X_{2}$:Type, ${\it info}$:($E$$\rightarrow$((:Id $\times$ $X_{1}$) + (:(:IdLnk $\times$ $E$) $\times$ $X_{2}$))), $e$:$E$, $f$:(Id$\rightarrow$$T$),\+ \\[0ex]$g$:(IdLnk$\rightarrow$$E$$\rightarrow$$T$). ecase1($e$;${\it info}$;$i$.$f$($i$);$l$,${\it e'}$.$g$($l$,${\it e'}$)) $\in$ $T$ \- \end{tabbing}