OK, I get it. I was confused by the fact that they both seem to work. But the version with let inside the defun needlessly recomputes the path every time it's called, and then the path immediately becomes garbage when the function exits.
<div><br></div><div>Ron, I've read your paper multiple times. I keep a copy of it in a handy place on my computer, along with my local copy of the hyperspec and other useful documents. I guess I need to read it a few more times yet. ;-) </div>
<div><br></div><div>FWIW, I'm working on tool for experimenting with tiling patterns, such as the one attached. My previous CL project used ltk, and I didn't want to use that again. I figured I would use either Cocoa/Quartz or maybe Cairo. I'm also looking at XMLisp.</div>