A General Theorem for Non-Simultaneous Hat Guessing Puzzles

TL;DR

This paper presents a general theorem on the existence of winning strategies for non-simultaneous hat guessing puzzles, exploring their relation to the Axiom of Choice and comparing with simultaneous strategies.

Contribution

It introduces a unifying theorem for non-simultaneous hat guessing puzzles and analyzes their connection to foundational set theory principles.

Findings

A general theorem guarantees winning strategies under certain conditions.

The construction of strategies relates to the Axiom of Choice.

Connections between non-simultaneous and simultaneous declaration strategies are discussed.

Abstract

The prisoners and hats puzzle, or simply the hat puzzle, is a family of games in which a group of prisoners are each assigned a colored hat and are asked to guess the color of their own hat. Various versions of the puzzle arise depending on the number of prisoners, the number of possible hat colors, and the information available to them before and after the game begins. These puzzles are broadly classified according to whether the prisoners' declarations are made simultaneously or non-simultaneously. In this paper we present a general theorem concerning the existence of a winning strategy when the declarations are non-simultaneous. We also discuss the relationship between the construction of such strategies and the Axiom of Choice, as well as their connection to the simultaneous-declaration case.