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arXiv · 2509.21744

Various Diamond Properties in Combinatorial Game Theory

Keiichirou Kusakari·Tomoaki Abuku
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Abstract

We investigate conditions under which positions in combinatorial games admit simple values. We introduce a unified diamond framework, the $\Diamond_A$-property ($A\in\{\mathbb{Z},\mathbb{D}$), for sets of positions closed under options. Under certain conditions, this framework guarantees that all values are integers, dyadic rationals, or pairs $\{m|n\}$ (on $\mathbb{Z}$ or $\mathbb{D}$). As an application, we establish that every position in \textsc{Yashima} game on bipartite graphs has an integer pair value.

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Keiichirou Kusakari, Tomoaki Abuku. 2025-12-28. Various Diamond Properties in Combinatorial Game Theory. https://arxiv.org/abs/2509.21744

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