PM-AGT-0020

An Agent MUST be able to declare a parent Agent, and MUST inherit the parent's privileges. The relation MUST be acyclic.

Non-normative: acyclicity is ours. No source says it, and privilege inheritance around a cycle either diverges or silently grants everything to everyone, depending on how the traversal is written. It is stated here rather than left to an implementation because both failure modes are security-relevant and neither is visible in a model review.