Non-deterministic systems

Multiway systems are examples of what are often in computer science called non-deterministic systems. The general idea of a non-deterministic system is to have rules with several possible outcomes, and then to allow each of these outcomes to be followed. Non-deterministic Turing machines are a common example. For most types of systems (such as Turing machines) such non-deterministic versions do not ultimately allow any greater range of computations to be performed than deterministic ones. (But see page 766.)