%0 Conference Proceedings %T Infinite Subgame Perfect Equilibrium in the Hausdorff Difference Hierarchy %+ Université libre de Bruxelles (ULB) %A Le Roux, Stéphane %< avec comité de lecture %( Lecture Notes in Computer Science %B 1st International Conference on Theoretical Computer Science (TTCS) %C Tehran, Iran %Y Mohammed Taghi Hajiaghayi %Y Mohammad Reza Mousavi %3 Topics in Theoretical Computer Science %V LNCS-9541 %P 147-163 %8 2015-08-26 %D 2015 %R 10.1007/978-3-319-28678-5_11 %K Infinite multi-player games in extensive form %K Subgame perfection %K Borel hierarchy %K Preference characterization %K Pareto-optimality %Z Computer Science [cs]Conference papers %X Subgame perfect equilibria are specific Nash equilibria in perfect information games in extensive form. They are important because they relate to the rationality of the players. They always exist in infinite games with continuous real-valued payoffs, but may fail to exist even in simple games with slightly discontinuous payoffs. This article considers only games whose outcome functions are measurable in the Hausdorff difference hierarchy of the open sets (i.e. ${ {\Delta }}^0_2$ when in the Baire space), and it characterizes the families of linear preferences such that every game using these preferences has a subgame perfect equilibrium: the preferences without infinite ascending chains (of course), and such that for all players a and b and outcomes x, y, z we have $\lnot (z <_a y <_a x \,\wedge \, x <_b z <_b y)$. Moreover at each node of the game, the equilibrium constructed for the proof is Pareto-optimal among all the outcomes occurring in the subgame. Additional results for non-linear preferences are presented. %G English %Z TC 1 %Z WG 1.8 %2 https://inria.hal.science/hal-01446258/document %2 https://inria.hal.science/hal-01446258/file/385217_1_En_11_Chapter.pdf %L hal-01446258 %U https://inria.hal.science/hal-01446258 %~ IFIP-LNCS %~ IFIP %~ IFIP-TC %~ IFIP-TC1 %~ IFIP-LNCS-9541 %~ IFIP-WG1-8 %~ IFIP-TTCS