Dear Bruce,
as the one putting up the question you mentioned I am willing to say something about it.
I am sure it might be trivial and also sure that most people here (well, I might include myself here) can write down the solution instantaneously.
So why did I ask?
First of all since I am interested in similar systems and knowing good resources that provide additional information in the context of the question would have been nice (in the sense of Marek's answer).
Second, I thought it might be a nice idea since in on of the threads concerning promotion, someone was suggesting to ask questions we know the answer of but it would be nice to have it answered on the site anyways, maybe from interesting perspectives (to create content, I suppose).
I was actually a little wondering about the reactions the post immediatly created regarding that a lot of the questions posted are actually on a High-School level. And, in turn, those seem to be the most popular onesmost popular ones.
Sincerely
Robert
PS.: I was the first to vote to close the question.