“…Often such a phenomenon can be conceptualised at different aggregation levels that can be identified. For example, for bacterial behaviour, the level of the bacterium as a whole, the level of its two main subprocesses control and metabolism, the level of subprocesses of these, transcription and translation, respectively, and catabolism, anabolism and transport, and the level of specific chemical reactions within such subprocesses; e.g., (Bosse, Jonker, and Treur, 2007). Modelling such phenomena according to different aggregation levels means that their dynamics is described by specifications at these different levels, connected by logical interlevel relations expressing, for example, that a certain specification at one aggregation level is entailed by a specification at the next lower level; e.g., .…”