\begin{tabbing}
ma{-}single{-}effect0($x$;$A$;$k$;$T$;$f$)
\\[0ex]$\,\equiv$$_{\mbox{\scriptsize def}}$$\;\;$\=with declarations \+
\\[0ex]ds:$x$ : $A$
\\[0ex]da:$k$ : $T$
\\[0ex]effect of $k$(v) is $x$ := $\lambda$$s$,$v$. $f$($s$($x$),$v$) s v
\-
\end{tabbing}