Control Conditions for Transformation Units : Parallelism, As-long-as-possible, and Stepwise Control

Abstract

The concept of graph transformation units is a formal and as well intuitive means to model processes on graphs. Thereby the control condition of a transformation unit plays an important role. It provides so to say the intelligence of the unit by describing its desired behaviour. The thesis regards control conditions focusing on two aspects: expressivity and practicability. Considering expressivity it implements two kinds of control conditions, as-long-as-possible and parallel expressions. As their names imply these control conditions are able to express the as-long-as-possible iteration respectively parallel composition of already described behaviour. Focusing on practical executability the thesis introduces the concept of stepwise control conditions. Whereas conventional control conditions in principle describe desired behaviour their computation may take a long time, since first all possible derivations have to be computed and then are checked against the control condition. Stepwise control conditions allow to directly guide the derivation process and so may save computation time.