Definition

1. An instance of <Primitive Summary Item> shall have a drm_class field value corresponding to one of the following:

   • <Primitive Feature> or one of its subclasses
   • <Primitive Geometry> or one of its subclasses
   • classes that may legally appear in the component tree of a <Primitive Feature> instance or <Primitive Geometry> instance

2. For any <Primitive Summary Item> instance B that is a component of another <Primitive Summary Item> instance A, the drm_class represented by B shall be defined as a formal component of A, and the multiplicity of B shall comply with the corresponding component relationship between the two classes.

3. For any <Primitive Summary Item> component S of an <Environment Root> instance ER, where the drm_class field corresponds to a class P, the component tree of ER shall contain at least one instance of P, either in its <Feature Hierarchy>, its <Geometry Hierarchy>, or both, such that the component tree of the instance of P conforms with the pattern specified by S.

4. For any <Primitive Summary Item> component S of a <Model> instance M, where the drm_class field corresponds to a class P, the component tree of M shall contain at least one instance of P, either in the <Feature Hierarchy> component tree of its <Feature Model> component, the <Geometry Hierarchy> component tree of its <Geometry Model> component, or both, such that the component tree of the instance of P conforms with the pattern specified by S.

Rationale

A <Primitive Summary Item> instance represents an instance or group of instances of a primitive class, possibly together with part of its component tree, where the pattern thus described appears in the given scope. Consequently, the pattern thus described shall correspond to some valid set of relationships.

Example

No example supplied.

FAQs

Can an "empty" <Model> instance have <Primitive Summary Item> components?

No; such summary information indicates the presence of instances which by definition are not present in an "empty" <Model> instance.