The class of fixed point problems. In the framework of fixed point problems, an instance I is associated with a (continuous) function FI, and a solution of I is a fixed point of FI.
Properties of FIXP problems:
Every FIXP problem has Partial Computation, Decision, (Strong) Approximation, and Existence counterparts; these can all be solved in PSPACE.
The Nash equilibrium problem for 3 or more players is FIXP-complete.
Linear-FIXP = PPAD.
Defined in [EY07].
No class.