Peter Geoghegan <pg@heroku.com> writes:
> Robert seemed to want to keep the example short, which I took on
> board, but I myself think that your more worked out treatment is
> better. I think this revision makes my point very well. I recommend
> committing it.
After further thought I realized that part of the point you'd been
making was that people might fail to distinguish the behaviors of
containment and existence operators in this regard. So I think the
example needs to make that point explicitly. I whacked it around
a bit more and committed it.
regards, tom lane