By around 1700 BC (just over a hundred years later), Egypt was fragmenting politically, with local kingdoms springing up in the northeastern delta area. One of these was that of King Nehesy, whose capital was at Avaris; he ruled over a population consisting largely of Syro-Canaanites who had settled in the area during the 12th Dynasty, and who were probably mainly soldiers, sailors, shipbuilders and workmen. His dynasty was probably replaced by a West-Semitic-speaking Syro-Canaanite dynasty that formed the basis of the later Hyksos kingdom, able to spread southwards because of the unstable political situation while aided by "an army, ships, and foreign connections." 
Many mathematical models of physical systems are deterministic. This is true of most models involving differential equations (notably, those measuring rate of change over time). Mathematical models that are not deterministic because they involve randomness are called stochastic . Because of sensitive dependence on initial conditions , some deterministic models may appear to behave non-deterministically; in such cases, a deterministic interpretation of the model may not be useful due to numerical instability and a finite amount of precision in measurement. Such considerations can motivate the consideration of a stochastic model even though the underlying system is governed by deterministic equations.