My deleting my original post deleted three responses, including mine, yours and Craig's. My goof. Bruce-yeah, I now see your by-line in your drawing. Your post certainly did help. Thanks. We've had a rash of bad stuff on SP and it's all a blur to me now. Thanks for putting this up. It's good stuff and more of it is needed on SP.
for the topos. these are one of the most useful posts SP