Conservation of normality for master-slave and strict discrete-event system composition

In this work the normality property of specification languages for discrete-event systems under partial observation is investigated in a modular context for large-scale systems-modelling. This is related to work on controllability done previously in a similar context by R. Wenck and J. H. Richter (2004). The problem of preserving normality under master-slave (biased synchronous composition, BSC) and strict composition (strict product composition, SPC) operations is defined, and sufficient conditions for preserving normality under application of these operators are provided.