What if we want: a) user transparency and b) diff views.
Model, View, Controller. Model <- View: addDependent. Model <- Model: changed: Aspect, Model <- Controler: app-specific. View <- Model: update: Aspect. Model < View: app-specific.
Java, similar idea. Observable, Observer.
Now to get distributed protocol. Not so easy - Anshu Problem.
Code application:
Centralized: create central process with multiple views and model.
Replicated: Each replica an observer/dependent of others.