In summary, the first introductory module that illustrated the concept
of optimality was the only one that met with all positive reviews, and the
second one would be acceptable with slight color modifications.
One can picture this situation by imagining that each party constructs
a continuous scale of its preferences ranging from its most preferred
outcome to its least favorite acceptable outcome.
The work of Ravara and Vasconcelos  improves such type systems by
allowing only messages possibly acceptable in some future state to be