## Notre Dame Journal of Formal Logic

### A Topological Approach to Yablo's Paradox

Claudio Bernardi

#### Abstract

Some years ago, Yablo gave a paradox concerning an infinite sequence of sentences: if each sentence of the sequence is 'every subsequent sentence in the sequence is false', a contradiction easily follows. In this paper we suggest a formalization of Yablo's paradox in algebraic and topological terms. Our main theorem states that, under a suitable condition, any continuous function from 2N to 2N has a fixed point. This can be translated in the original framework as follows. Consider an infinite sequence of sentences, where any sentence refers to the truth values of the subsequent sentences: if the corresponding function is continuous, no paradox arises.

#### Article information

Source
Notre Dame J. Formal Logic Volume 50, Number 3 (2009), 331-338.

Dates
First available in Project Euclid: 10 November 2009

http://projecteuclid.org/euclid.ndjfl/1257862041

Digital Object Identifier
doi:10.1215/00294527-2009-014

Mathematical Reviews number (MathSciNet)
MR2572977

Zentralblatt MATH identifier
1190.03003

#### Citation

Bernardi, Claudio. A Topological Approach to Yablo's Paradox. Notre Dame J. Formal Logic 50 (2009), no. 3, 331--338. doi:10.1215/00294527-2009-014. http://projecteuclid.org/euclid.ndjfl/1257862041.

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