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