“…There have been many studies of stochastic and hydrodynamic models, or fractal situations, involving such situations and we mention in particular [9,10,11,12,13,17,18,23,24,29,30,31,32,33,42,43,47,48,49,51,52,54,56,61,62,63]; a survey of some of this appears in [9]. For various geometrical considerations related to the emergence question see also [3,7,8,19,35,36,37,38,39,40,41,46].…”