Technical Report CS0060

Title: A Combinatorial Problem Which Is Complete In Polynomial Space
Authors: S. Even and R.E. Tarjan
Abstract: We consider a generalization, which we call the Shannon switching game on vertices, of a familiar board game called HEX. We show that determining who wins such a game if each player plays perfectly is very hard; In fact, it is as hard as carrying out any polynomial-spacebounded computation. This result suggests that the theory of combinatorial games is difficult.

Keywords: computational complexity, HEX, Shannon switching game, completeness in polynomial space.

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