The core cover in relation to the nucleolus and the Weber set

The class of games for which the core coincides with the core cover (compromise stable games) is characterized. Moreover an easy explicit formula for the nucleolus for this class of games is developed, using an approach based on bankruptcy problems. Also, the class of convex and compromise stable games is characterized. The relation between the core cover and the Weber set is studied and it is proved that under a weak condition their intersection is nonempty.