\begin{tabbing}
$\forall$\=$i$:Id, ${\it ds}$:$x$:Id fp$\rightarrow$ Type, ${\it da}$:$k$:Knd fp$\rightarrow$ Type, $A$:ecl(${\it ds}$;${\it da}$), ${\it upd}$:update{-}spec(${\it ds}$;${\it da}$), ${\it es}$:ES,\+
\\[0ex]$z$:Id.
\-\\[0ex]$z$ $\in$ dom(${\it ds}$) $\Rightarrow$ @$i$[[$A$;${\it upd}$]] $\in$ Prop
\end{tabbing}