English

Muddy Waters

Logic in Computer Science 2025-12-01 v1

Abstract

In the 2013 Advent calender of the Berlin Mathematics Research Center MATH+, Gerhard Woeginger presents a novel hat problem with an uncommon initial announcement. Although the information given is insufficient for the hat bearers to learn their colour, they are informed that the colours have been chosen so that they can learn their colour. We formalize this announcement in public announcement logic and in an extension of public announcement logic with fixpoints.

Cite

@article{arxiv.2511.22392,
  title  = {Muddy Waters},
  author = {Hans van Ditmarsch},
  journal= {arXiv preprint arXiv:2511.22392},
  year   = {2025}
}

Comments

In Proceedings TARK 2025, arXiv:2511.20540

R2 v1 2026-07-01T07:57:57.545Z