English

An Impossible Asylum

Logic 2022-04-26 v2 Logic in Computer Science

Abstract

In 1982, Raymond Smullyan published an article, "The Asylum of Doctor Tarr and Professor Fether," that consists of a series of puzzles. These were later reprinted in the anthology, "The Lady or The Tiger? and Other Logic Puzzles." The last puzzle, which describes the asylum alluded to in the title, was designed to be especially difficult. With the help of automated reasoning, we show that the puzzle's hypotheses are, in fact, inconsistent, which is to say, no such asylum can possibly exist.

Cite

@article{arxiv.2112.02142,
  title  = {An Impossible Asylum},
  author = {Jeremy Avigad and Seulkee Baek and Alexander Bentkamp and Marijn Heule and Wojciech Nawrocki},
  journal= {arXiv preprint arXiv:2112.02142},
  year   = {2022}
}
R2 v1 2026-06-24T08:03:43.684Z