Definition

1.	An instance of <Hierarchy Summary Item> shall have a drm_class field value corresponding to either: <Feature Hierarchy> or one of its subclasses <Geometry Hierarchy> or one of its subclasses
2.	For any <Hierarchy Summary Item> instance B that is a component of another <Hierarchy Summary Item> instance A, the class represented by B's drm_class field value shall be defined as a formal component of A, and the multiplicity and multiplicity_meaning of B shall comply with the corresponding component relationship between the two classes.
3.	Consider an <Environment Root> instance ER.
	3.1 If ER has a <Geometry Hierarchy> component GH, ER shall have at most one <Hierarchy Summary Item> component HS_G for which the drm_class field corresponds to a <Geometry Hierarchy> subclass. If such a component instance HS_G exists, its field values shall comply with the following constraints.   3.1.1 HS_G's drm_class shall match that of GH. 3.1.2 HS_G's multiplicity_meaning shall be SE_HS_MLTPCTY_CODE_EXACT, and its multiplicity shall be 1. 3.2 If ER does not have a <Geometry Hierarchy> component, ER shall not have any <Hierarchy Summary Item> component for which the drm_class field corresponds to a <Geometry Hierarchy> subclass. 3.3 If ER has a <Feature Hierarchy> component FH, ER shall have at most one <Hierarchy Summary Item> component HS_F for which the drm_class field corresponds to a <Feature Hierarchy> subclass. If such a component instance HS_F exists, its field values shall comply with the following constraints.   3.3.1 HS_F's drm_class shall match that of FH. 3.3.2 HS_F's multiplicity_meaning shall be SE_HS_MLTPCTY_CODE_EXACT, and its multiplicity shall be 1. 3.4 If ER does not have a <Feature Hierarchy> component, ER shall not have any <Hierarchy Summary Item> component for which the drm_class field corresponds to a <Feature Hierarchy> subclass.
4.	Consider a <Model> instance M.
	4.1 If M has a <Geometry Model> with a <Geometry Hierarchy> component GH, M shall have at most one <Hierarchy Summary Item> component HS_G for which the drm_class field corresponds to a <Geometry Hierarchy> subclass. If such a component instance HS_G exists, its field values shall comply with the following constraints.   4.1.1 HS_G's drm_class shall match that of GH. 4.1.2 HS_G's multiplicity_meaning shall be SE_HS_MLTPCTY_CODE_EXACT, and its multiplicity shall be 1. 4.2 If M does not have a <Geometry Model> component, or its <Geometry Model> does not have a <Geometry Hierarchy> component, M shall not have any <Hierarchy Summary Item> component for which the drm_class field corresponds to a <Geometry Hierarchy> subclass. 4.3 If M has a <Feature Model> with a <Feature Hierarchy> component FH, M shall have at most one <Hierarchy Summary Item> component HS_F for which the drm_class field corresponds to a <Feature Hierarchy> subclass. If such a component instance HS_F exists, its field values shall comply with the following constraints.   4.3.1 HS_F's drm_class shall match that of FH. 4.3.2 HS_F's multiplicity_meaning shall be SE_HS_MLTPCTY_CODE_EXACT, and its multiplicity shall be 1. 4.4 If M does not have a <Feature Model> component, or its <Feature Model> does not have a <Feature Hierarchy> component, M shall not have any <Hierarchy Summary Item> component for which the drm_class field corresponds to a <Feature Hierarchy> subclass.
5.	All <Geometry Hierarchy> associates (or <Feature Hierarchy> associates) of a given <Hierarchy Summary Item> instance shall be instances of the class specified by its drm_class field value, and shall conform to the structure that it specifies.

Rationale

A <Hierarchy Summary Item> component of an <Environment Root> or <Model> exists to summarize a corresponding hierarchy of its aggregate. Consequently, its drm_class and multiplicity shall be consistent with the hierarchy which it represents.

Example

No Example supplied.

FAQs

No FAQs supplied.