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27 votes
1 answer
2k views

Are Conway's combinatorial games the "monster model" of any familiar theory?

This is related to this question about a "mother of all" groups, and so seemed like it'd fit in better at MO than MSE. If I understand the answer to that question correctly, the surreal numbers have ...
Mike Battaglia's user avatar
25 votes
4 answers
2k views

The Chocolatier's game: can the Glutton win with a restricted form of strategy?

I have a question about the Chocolatier's game, which I had introduced in my recent answer to a question of Richard Stanley. To recap the game quickly, the Chocolatier offers up at each stage a finite ...
Joel David Hamkins's user avatar
24 votes
2 answers
1k views

What is the complexity of the winning condition in infinite Hex? In particular, is infinite Hex a Borel game?

Consider the game of infinite Hex, where two players Red and Blue alternately place their stones on the infinite hex grid, each aiming to create a winning configuration. Red wins after infinite play, ...
Joel David Hamkins's user avatar
9 votes
2 answers
691 views

Choosing subsets of $\mathbb R$ of cardinality $\frak c$, who wins?

Consider the following infinite game: two players, I and II, are alternating and choosing a descending sequence of subsets of $\mathbb R$ of cardinality $\frak c$, so I chooses a set $A_1\subseteq\...
Wojowu's user avatar
  • 28.2k
7 votes
2 answers
736 views

Sets as Combinatorial Games

Just a few days ago my seemingly eternal and recurrent fascination for Conway's combinatorial game theory (CGT) & surreal numbers had a recrudescence, so I grabbed this excellent survey, and began ...
Mirco A. Mannucci's user avatar
5 votes
1 answer
436 views

Uniform strategy on Kastanas' game

I think my question applies to most games, but for the sake of concreteness, I shall consider one specific game in this question. We consider the game posed by Ilias Kastanas in his paper On the ...
Clement Yung's user avatar
  • 1,442
5 votes
1 answer
503 views

What ordinal corresponds to the T(3)?

Let's play a game. You start with the ordinal $\alpha$ and I start with the empty sequence. Each turn, you decrease your ordinal, and I add a tree (where each node can have one of three labels), ...
Christopher King's user avatar
5 votes
1 answer
1k views

Set theory / Formal logic of Baba is You

''Baba is You'' is a recent puzzle game in which the player builds a set of rules by pushing squares with words written on them. If we leave aside the combinatorial difficulty of how to move the ...
Hollis Williams's user avatar
5 votes
0 answers
396 views

Why is this transfinite game not determined?

This question originates from the paper On the Axiom of Determinateness by Jan Mycielski, section 7. Given a set $X$ and an ordinal $\alpha$, the author defines a transfinite game of length $\alpha$ ...
John Gowers's user avatar