\begin{tabbing} $\forall$\=$k$:Knd, $l$:IdLnk, ${\it ds}$:$x$:Id fp$\rightarrow$ Type, ${\it da}$:$a$:Knd fp$\rightarrow$ Type, $f$:(Id$\times$Top) List, $x$:Id, $k_{1}$:Knd,\+ \\[0ex]$d_{1}$:$x$:Id fp$\rightarrow$ Type, $d_{2}$:$a$:Knd fp$\rightarrow$ Type, $f_{1}$:Top. \-\\[0ex]${\it ds}$ $\parallel$ $d_{1}$ \\[0ex]$\Rightarrow$ ${\it da}$ $\parallel$ $d_{2}$ \\[0ex]$\Rightarrow$ (\=with declarations \+ \\[0ex]ds:${\it ds}$ \\[0ex]da:${\it da}$ \\[0ex]$k$(v) sends $f$ s v on link $l$ \\[0ex]$\Vert\!+$ \=with declarations \+ \\[0ex]ds:$d_{1}$ \\[0ex]da:$d_{2}$ \\[0ex]effect of $k_{1}$(v) is $x$ := $f_{1}$ s v) \-\- \end{tabbing}