This lecture covers the concepts of causal and total order broadcast in distributed algorithms. It includes exercises on adding total-order property, deterministic message sorting, and consensus-based total-order broadcast. The solutions demonstrate scenarios with faulty and correct processes, ensuring total order. The transformation between consensus and total-order broadcast abstractions is discussed, along with the implementation details. Sequential objects and their operations are explained, with a guided exercise on Asset Transfer objects. A bonus exercise challenges students to use Total Order Broadcast for implementing an Asset Transfer object.