Answer:
The UIDs for a set of hierarchical entities can be propagated through multiple "recursive" relationships.
Step-by-step explanation:
In the context of hierarchical entities and their UIDs (Unique Identifiers), a **recursive** relationship implies that the relationship between entities loops back to the same type of entity within the hierarchy. This recursion can occur at multiple levels within the hierarchy.
1. **Hierarchical Entities**: These are entities organized in a hierarchical structure, often resembling a tree-like arrangement. Each entity has a UID to uniquely identify it within the hierarchy.
2. **Recursive Relationship**: When we say the relationship is "recursive," it means that an entity can have a relationship with another entity of the same type within the hierarchy. For example, a folder can contain subfolders, and each subfolder is also a folder.
3. **Propagation of UIDs**: As entities are organized hierarchically, their UIDs can be propagated or inherited through these recursive relationships. When a sub-entity is created within another entity, it often inherits or is assigned a UID related to its parent entity, indicating its position within the hierarchy. This propagation ensures that each entity remains uniquely identifiable within the entire hierarchy.
So, the term "recursive" is used here to describe relationships within the hierarchical structure where entities of the same type can be related to each other, and UIDs can be carried through these relationships to maintain unique identification.