x.click -> x.pdf

[Eddie Kohler]

Hi Scott,

> (Knowing nothing about metapost,) I suspect the problem is the
> definition of emptyqueueit at line 273 of samp01_examples.mp:
> 
>   vardef emptyqueueit@#(expr s) =
>     _elementit.@#(s, 1, 1, push_to_pull, false);
> 
> is missing the sixth argument to _elementit (which all other uses of
> _elementit seem to have). Naively appending "false" to the argument list
> allows the compilation to proceed.

That's exactly the right thing to do; checked in the fix. Thanks!

Also, I explicitly checked in the copyright and license assignments to the
diagram files.

Eddie