\begin{tabbing}
R{-}self{-}interface($R$)
\\[0ex]$\,\equiv$$_{\mbox{\scriptsize def}}$$\;\;$\=case $R$ of \+
\\[0ex]Rnone =$>$ True
\\[0ex]Rplus(${\it left}$,${\it right}$)=$>$${\it rec}_{1}$,${\it rec}_{2}$.${\it rec}_{1}$ \& ${\it rec}_{2}$
\\[0ex]Rinit(${\it loc}$,$T$,$x$,$v$)=$>$ True
\\[0ex]Rframe(${\it loc}$,$T$,$x$,$L$)=$>$ True
\\[0ex]Rsframe(${\it lnk}$,${\it tag}$,$L$)=$>$ True
\\[0ex]Reffect(${\it loc}$,${\it ds}$,${\it knd}$,$T$,$x$,$f$)=$>$ True
\\[0ex]Rsends(${\it ds}$,${\it knd}$,$T$,$l$,${\it dt}$,$g$)=$>$ isrcv(${\it knd}$) $\Rightarrow$ lnk(${\it knd}$) $=$ $l$ $\Rightarrow$ ${\it dt}$(tag(${\it knd}$))?Void $\subseteq\rho$ $T$
\\[0ex]Rpre(${\it loc}$,${\it ds}$,$a$,$T$,$P$)=$>$ True
\\[0ex]Raframe(${\it loc}$,$k$,$L$)=$>$ True
\\[0ex]Rbframe(${\it loc}$,$k$,$L$)=$>$ True
\\[0ex]Rrframe(${\it loc}$,$x$,$L$)=$>$ True
\-
\end{tabbing}