Self-Correcting Gossip Protocols
Epistemic gossip protocols usually assume error-free message transmission. The paper asks which epistemic goals remain reachable when one transmission error may occur, and how optimality is affected without a central coordinating authority.
A dynamic epistemic logic is defined over secret distributions and call sequences containing at most one faulty call, with an observation relation and satisfaction semantics. It is compared with bounded-memory (last-call) and full-information call semantics. The mutually recursive definitions are formalized in Lean 4 using Mathlib. Lean is used to show that the evaluation function terminates under a lexicographic order.
The work shows how agents can self-correct faulty secret values and how this affects the optimal number of calls. The Lean formalization verifies well-foundedness of the semantics, proves that the observation relation is an equivalence relation, and proves properties of knowledge and belief.
