Relating Knowledge and Coordinated Action: The Knowledge of Preconditions Principle
This work addresses the foundational problem of coordination in multi-agent systems, providing a formal principle that can guide protocol design, but it is incremental as it builds on existing knowledge-action theories.
The paper tackles the problem of connecting knowledge and action in multi-agent systems by proposing the Knowledge of Preconditions principle, which asserts that knowing necessary conditions is required for performing actions, and it is formalized and proven to hold in a wide class of settings, extending well-known connections like common knowledge for simultaneous actions.
The Knowledge of Preconditions principle (KoP) is proposed as a widely applicable connection between knowledge and action in multi-agent systems. Roughly speaking, it asserts that if some condition is a necessary condition for performing a given action A, then knowing that this condition holds is also a necessary condition for performing A. Since the specifications of tasks often involve necessary conditions for actions, the KoP principle shows that such specifications induce knowledge preconditions for the actions. Distributed protocols or multi-agent plans that satisfy the specifications must ensure that this knowledge be attained, and that it is detected by the agents as a condition for action. The knowledge of preconditions principle is formalised in the runs and systems framework, and is proven to hold in a wide class of settings. Well-known connections between knowledge and coordinated action are extended and shown to derive directly from the KoP principle: a "common knowledge of preconditions" principle is established showing that common knowledge is a necessary condition for performing simultaneous actions, and a "nested knowledge of preconditions" principle is proven, showing that coordinating actions to be performed in linear temporal order requires a corresponding form of nested knowledge.