\begin{new}
X3J13 voted in January 1989
\issue{VARIABLE-LIST-ASYMMETRY}
to regularize the binding formats for \cd{do}, \cd{do*}, \cd{let},
\cd{let*}, \cd{prog}, \cd{prog*}, and \cd{compiler-let}.
The new syntactic definition for \cd{let} makes the {\it value} optional:

\begin{defmac}
let ({var | (var [value])}*) {declaration}* {\,form}*

This changes \cd{let} to allow a list \cd{({\it var})} to appear,
meaning the same as simply {\it var}.
\end{defmac}
\end{new}
%%% Note use of \, above to keep tail of italic "f" from hitting the left brace.


\begin{defun}[Function]
mapcar function list &rest more-lists \\
maplist function list &rest more-lists \\
mapc function list &rest more-lists \\
mapl function list &rest more-lists \\
mapcan function list &rest more-lists \\
mapcon function list &rest more-lists

For each of these mapping functions,
the first argument is a function and the rest must be lists.
The function must take as many arguments as there are lists.
...
\end{defun}