The class SDMNDI is a container for the shared SCE:SCEStyle and all the SDMNDiagrams defined in a SharedDataModel. A list of SDMNDiagrams. A list of shared SCEStyle that can be referenced by all SDMNDiagrams diagrams and SDMNDiagramElements. The class SDMNDiagram specializes SCE:SCEDiagram, which specializes DI::Diagram. It is a kind of Diagram that represents a depiction of all or part of a SDMNDiagram. SDMNDiagram is the container of SDMNDiagramElement (SDMNShape(s) and SDMNEdge(s)). SDMNDiagram cannot include other SDMNDiagrams. A SDMNDiagram can define a SCE:SCEStyle locally and/or it can refer to a shared one defined in the SDMNDI. Properties defined in the local style overrides the one in the referenced shared style. That combined style (shared and local) is the default style for all the SDMNDiagramElement contained in this SDMNDiagram. The SDMNDiagram class represents a two-dimensional surface with an origin of (0, 0) at the top left corner. This means that the x and y axes have increasing coordinates to the right and bottom. Only positive coordinates are allowed for diagram elements that are nested in a SDMNDiagram. Element Role: diagramElement A list of SDMNDiagramElements (SDMNShape and SDMNEdge) that are depicted in the SDMNDiagram. This redefines the diagramElement association within the SCE:SCEDiagram element. This element should never be instantiated directly, but rather concrete implementation should. It is placed there only to be referred in the sequence. The SDMNDiagramElement class is contained by the SDMNDiagram and is the base class for SDMNShape and SDMNEdge. SDMNDiagramElement inherits its styling from its parent SCEDiagram. In addition, it can refer to one of the shared SCE:SCEStyle defined in the SDMNDI and/or it can define a local style. See section below for more details on styling. SDMNDiagramElement MAY also contain a SCE:SCELabel when it has a visible text label. If no SCE:SCELabel is defined, the SDMNDiagramElement should be depicted without a label. The SDMNEdge class specializes SCE:SCEEdge, which specializes DI::Edge and SCE:SCEDiagramElement. It is a kind of edge that can depict a relationship between two SDMNDiagram model elements. SDMNEdge are used to depict Connectors or Associations in the SDMNDiagram model. Since SDMNDiagramElement might be depicted more than once, sourceElement and targetElement attributes allow to determine to which depiction a SDMNEdge is connected. When SDMNEdge has a source, its sourceModelElement MUST refer to the SDMNDiagramElement it starts from. That SDMNDiagramElement MUST resolved to the SCE:SCEElement that is the actual source of the Connector or Association. For Requirement, this is the required SCE:SCEElement. When it has a target, its targetModelElement MUST refer to the SCEDiagramElement where it ends. That SDMNDiagramElement MUST resolved to the SCE:SCEElement that is the actual target of the Connector or Association. The SDMNShape class specializes SCE:SCEShape, which specializes DI::Shape and SCE:SCEDiagramElement. It is a kind of shape that depicts a SCEElement from the SDMNDiagram model. SDMNShape represents a Data Item or a SCE DiagramArtifacts Group or a Text Annotation that is depicted on the diagram. SDMNDiagram models may add additional shapes to their diagrams. SDMNShape has no additional properties but a SDMNDiagram model may extend this class to add properties that are used to further specify the appearance of some shapes that cannot be deduced from the SDMNDiagram model.