Gee, David, I'm sorry to hear you're leaving. You seem pretty interested in math, so I'm surprised you're making a conscious choice to drop it even as a hobby. I'm very sympathetic to your employment plight, having been without a job myself for longer than seven months (and longer than I care to reveal). I wish you well in all your endeavors. Feel free to come back here anytime you want. Best, Dan Asimov