The files in this directory are written in the S-Lang language, which
is the extension language of the editor.  See
http://space.mit.edu/%7Edavis/slang.html for more information about
the language.

Please note that much of the code in these files may not be
understandable to those with little exposure to S-Lang.  Some of the
code has been written in such a way that it byte-compiles to as few
bytes as possible.  For example, consider the go_down function which
is used as:

    go_down (10);    % Move down 10 lines

site.sl defines this function as:

   define go_down() { () = down(); }

which makes it appear not to take any arguments as all.  However, this
is equivalent to:

   define go_down (n) { () = down (n); }

but the body of the latter version requires twice as many byte-codes.
The implemented version allows the argument passed to `go_down' to
stay on the stack to be picked up by the `down' function.

