Returns the value of Decomposes attribute. This attribute represents references to the decomposition relationship being an aggregation. It determines that this object definition is a part within an unordered whole/part decomposition relationship. An object definitions can only be part of a single decomposition (to allow hierarchical structures only).

IFC4 CHANGE: The inverse attribute data type has been changed from the supertype IfcRelDecomposes to subtype IfcRelAggregates.