Safety versus Liveness: Four Probes, Four Verdicts, One Assumption Rule Diagram

Independent failure

Permanent partition kills liveness and leaves safety alone
Lost dedup kills safety and leaves liveness alone
Each property needs its own counterexample

Vacuous safety

Zero effects means zero duplications: safety holds empty
But nothing ever progresses, so liveness is dead
A green safety light alone never means healthy

State assumptions

Progress assumes the partition heals and capacity exists
Every liveness claim ships with a stated time bound
Persist dedup across the restart that causes the redelivery