+\begin{describe}{fun}{reify-variable-argument-tail @<arguments> @> @<list>}
+ If the @<argument> list contains an @|:ellipsis| marker, then replace it
+ with a @|va_list|. The name for the new argument, if any, is taken from
+ the \descref{*sod-ap*}[variable]{var}. The new list is returned; the
+ original list is not modified, but may share structure with the new list.
+\end{describe}
+