The handler passed to call-with-continuation-prompt is only called if the continuation up to teh same prompt tag is aborted by abort-current-continuation, correct?
If that's the case, wouldn't it be more understandable to name it something like abort-handler? Another confusing part is that call-with-continuation-prompt takes an argument named thunk, and in its description, it says "The default handler is a procedure that takes a single argument thunk." This "thunk" is totally unrelated to the former thunk argument; it might be better to give it a different name.