 Moreover, there is a burgeoning literature of physical or quasi-physical systems, usually set in the context of classical physics, that carry out supertasks (see Earman and Norton (1998) and the entry on  supertasks  for a review). Frequently, the puzzle presented is to decide, on the basis of the well-defined behavior before time t = a, what state the system will be in at t = a itself. A failure of CM to dictate a well-defined result can then be seen as a failure of determinism.