In this chapter we've learned about the stateful sessions, what they are used for, and how they keep their state between session invocations. This is especially useful in long, iterative, interaction scenarios. For example, in a web application where a user logs in to the system, makes a couple of changes in multiple HTTP requests, and logs out of the system.

Also, logical assertions were discussed. They are automatically retracted when none of the conditions that inserted them are true. This is useful as it keeps the validation report updated all the time.

Finally, the serialization section discussed two options of serializing a stateful session: identity and serialized. An example was given of how to serialize the stateful service, which contained a stateful session.