User:Paul.w.goldberg/4-Nash

4-Nash is the problem of computing an approximate Nash equilibrium of a 4-player game in normal form. In contrast with 2-player games in normal form, games with more than two players have the problem that the numerical values that may arise in the solution, are not necessarily rational numbers, a fact that was known from Nash's original paper.

Generally, for positive integers $$k$$, $$k$$-Nash is the problem of solving a $$k$$-player game in normal form. The focus on this sequence of computational problems, and 4-Nash in particular, first arose in, which showed that 4-Nash has the same complexity as k-Nash for any larger value of k. That paper is a precursor of subsequent papers that established that computing a Nash equilibrium is PPAD-complete.