UNCONVENTIONAL COMPUTING PROBLEMS ? Selim

An evolving computation is one whose characteristics vary during its execution. These variations have many di erent origins and can manifest themselves in several ways. Thus, for example, the parameters of a computation, such as the data it uses, may vary with time independently of the computational environment in which the computation is carried out. Alternatively, it may be that the data interact with one another during the computation thus changing each other's value irreversibly. In this paper we describe a number of evolving computational paradigms, such as computations with time-varying variables, interacting variables, time-varying complexity, and so on. We show that evolving computations demonstrate the impossibility of achieving universality in computing, be it conventional or unconventional.