Membrane Computing with External Output

A super-cell system consists of computing cells which are organized hierarchically by the inclusion relation: cells may include cells, which again may include cells, etc. Each cell is enclosed by its membrane. Each cell is an independent computing agent with its own computing program, which produces objects. The interaction between cells consists of the exchange of objects through membranes. The output of a computation is a partially ordered set of objects which leave the super-cell through its external membrane. The fundamental properties of computations in such super-cell systems with external output are investigated. These include the computing power, normal forms, and basic decision problems.