[math-fun] GMail is embarrassing me

I said [I have no idea how or why GMail sent two copies of this.] Due to marginal connectivity, > ½ the time I click Send, GMail says "An error occurred and your message was not sent". This sometimes gives me a chance to add a couple of afterthoughts before retrying. But GMail turns out to be lying--the message *was* sent, at least to some recipients, so it looks like I'm bothering you all with resends of trivial afterthoughts. --rwg