Abstract
In this paper, we present a framework in which we analyze three riddles about truth that are all (originally) due to Smullyan. We start with the riddle of the yes-no brothers and then the somewhat more complicated riddle of the da-ja brothers is studied. Finally, we study the Hardest Logic Puzzle Ever (HLPE). We present the respective riddles as sets of sentences of quotational languages, which are interpreted by sentence-structures. Using a revision-process the consistency of these sets is established. In our formal framework we observe some interesting dissimilarities between HLPE’s available solutions that were hidden due to their previous formulation in natural language. Finally, we discuss more recent solutions to HLPE which, by means of self-referential questions, reduce the number of questions that have to be asked in order to solve HLPE. Although the essence of the paper is to introduce a framework that allows us to formalize riddles about truth that do not involve self-reference, we will also shed some formal light on the self-referential solutions to HLPE.
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References
Boolos George: ‘The hardest logic puzzle ever’. The Harvard Review of Philosophy 6, 62–65 (1996)
(director), Jim Henson, ‘The labyrinth’, 1986.
Gupta Anil: ‘Truth and paradox’. Journal of Philosophical Logic 11, 1–60 (1982)
Rabern Brain, Landoln Rabern: ‘A simple solution to the hardest logic puzzle ever’. Analysis 68, 105–112 (2008)
Roberts Tim: ‘Some thoughts about the hardest logic puzzle ever’. Journal of Philosophical Logic 30, 609–612 (2001)
Smullyan Raymond: What is the name of this book?. Englewood Cliffs, NJ, Prentice Hall (1978)
Uzquiano Gabriel: ‘How to solve the hardest logic puzzle ever in two questions’. Analysis 70, 39–44 (2010)
Wintein, Stefan, ‘On languages that contain their own ungroundedness predicate’, To appear in: Logique et Analyse, 2011.
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Wintein, S. A Framework for Riddles about Truth that do not involve Self-Reference. Stud Logica 98, 445–482 (2011). https://doi.org/10.1007/s11225-011-9343-1
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DOI: https://doi.org/10.1007/s11225-011-9343-1