If you use a let within the init-form of an outer let, the result is
invalid javascript code.
Here is a simplified example:
(ps (let ((x (let ((y (a)))
(b)
y)))
(1+ x)))
==>
"(function () {
var y;
var x = (y = a(), (b(), y));
return x + 1;
})();"
Not that I would normally write such code, but the inner "let" was
generated by a macro.
And many macros use "let"* *with gensyms. In my case, the macro used
"ps-once-only".
Andy Peterson