McLennan, Andrew; Tourky, Rabee - In: Journal of Mathematical Economics 44 (2008) 7-8, pp. 807-821
We introduce a combinatorial abstraction of two person finite games in an oriented matroid. We also define a combinatorial version of Nash equilibrium and prove that an odd number of equilibria exists. The proof is a purely combinatorial rendition of the Lemke-Howson algorithm.