A partial sequence diagram that implements the above use case is given below. Library Interface 26 27 Patron 1: LendBook() 1.1: Provide ID 2: VerifyID() 2.1: VerifyID() 2.2: Result() 2.3: Determine Due date 2.10: Lend Book Result 28 28 2.4: UpdateBook() 2.5: Updated Data 1 2.6: UpdatePatron() 2.7: Updated Data 2.8: SetStatus() 2.9: Status 29 29