AI-generated summary
The article discusses the benefits of L3s, which are applications with different requirements such as privacy, performance, and centralization vs decentralization. The first layer is slow and congested because each verification program needs to recompute and verify transactions. The second layer is faster as a single sequencer generates blocks and others only need to verify their validity. The article mentions Stark ex as a typical L2 use case for optimizing apps. AllStar uses language to express these statements and gathers evidence to verify the correctness of L2 transactions.