In this paper, a generalized version of the Fan-Knaster-Kuratowski-Mazurkiewicz lemma is obtained and used to prove the existence of fixed points for correspondenced defined on a generalized convex spaces. A result on the existence of maximal elements is deduced and is applied to prove the...

The core of an economy consists of those states of the economy which no group of agents (coalition) can "improve upon". A coalition can improve upon a state of the economy if, by using the means available to that group, each member can be made better off. This paper presents the notion of the...