\begin{tabbing}
Rds($R$)
\\[0ex]$\,\equiv$$_{\mbox{\scriptsize def}}$$\;\;$es\_realizer\_ind(\=$R$;\+
\\[0ex]fpf{-}empty;
\\[0ex]${\it left}$,${\it right}$,${\it rec}_{1}$,${\it rec}_{2}$.fpf{-}empty;
\\[0ex]${\it loc}$,$T$,$x$,$v$.fpf{-}single($x$; $T$);
\\[0ex]${\it loc}$,$T$,$x$,$L$.fpf{-}single($x$; $T$);
\\[0ex]${\it lnk}$,${\it tag}$,$L$.fpf{-}empty;
\\[0ex]${\it loc}$,${\it ds}$,${\it knd}$,$T$,$x$,$f$.${\it ds}$;
\\[0ex]${\it ds}$,${\it knd}$,$T$,$l$,${\it dt}$,$g$.${\it ds}$;
\\[0ex]${\it loc}$,${\it ds}$,$a$,$T$,$P$.${\it ds}$;
\\[0ex]${\it loc}$,$k$,$L$.fpf{-}empty;
\\[0ex]${\it loc}$,$k$,$L$.fpf{-}empty;
\\[0ex]${\it loc}$,$x$,$L$.fpf{-}empty)
\-
\end{tabbing}