[math-fun] Dan Weinreb

<from the grapevine -- long twisty path omitted -- rcs> I am very sorry to report that Dan Weinreb passed away this morning. Dan was a founder of our local technology community, working on the Lisp Machine at MIT in the 1970s, as a founder of Symbolics in the early 1980s, later as founder of the object database company Object Design, and as our colleague at ITA Software and Google since 2006. Dan was a wonderful man, and will be missed.