[math-fun] Distributivity of addition over multiplication

Of course x + yz = (x + y)(x + z) is not true in general for (x,y,z) in R^3. But I don't think I would have guessed which (x,y,z) in R^3 that it does hold for. It only takes a few seconds to figure out what this set is. But can someone give an intuitive reason for why it is what it is? --Dan _____________________________________________________________________ "It don't mean a thing if it ain't got that certain je ne sais quoi." --Peter Schickele