[math-fun] Cartesian product isn't associative

My tutor Julian points out an inconvenient fact: R x (R x R) = {(x,(y,z))} and (R x R) x R = {((x,y),z)} and neither = Euclidean 3Space {(x,y,z)} = R x R x R . What is the approved way to sweep this under the rug? --rwg Earlier quasiperiodic Somos results: http://arxiv.org/pdf/math/0703470