This containment relationship creates the hierarchical decomposition of Models. Any object must have at most one parent, and that parent must be a Model. Aspects provide primarily visibility control. Every Model has a predefined set of Aspects. Each part can be visible or hidden in an Aspect.
Every part has a set of primary aspects where it can be created or deleted.
The simplest way to express a relationship between two objects in GME is with a Connection. Connections can be directed or undirected. Connections can have Attributes themselves. The paradigm specifications can define sev-eral kinds of Connections. It is also specified what kind of object can participate in a given kind of Connection.