Shellshear, Evan; Sudhölter, Peter - In: Games and Economic Behavior 67 (2009) 2, pp. 633-644
If a TU game is extendable, then its core is a stable set. However, there are many TU games with a stable core that are not extendable. A coalition is vital if there exists some core element x such that none of the proper subcoalitions is effective for x. It is exact if it is effective for some...