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On the persistent difficulty of disjunction
pp. 77-90
Abstract
We want to show, in this paper, that, in intuitionistic analysis, the union of two closed subsets of Baire space N is not always closed, and that, more generally, the union of a closed set and a II n 0-set is not always II n+10. In the proof of this fact we make use of the intuitionistic Borel Hierarchy Theorem, established in (Veldman, 1981) and (Veldman, 2001a).
Publication details
Published in:
Rojszczak Artur, Cachro Jacek, Kurczewski Gabriel (2003) Philosophical dimensions of logic and science: selected contributed papers from the 11th international congress of logic, methodology, and philosophy of science, Kraków, 1999. Dordrecht, Springer.
Pages: 77-90
DOI: 10.1007/978-94-017-2612-2_7
Full citation:
Veldman Wim (2003) „On the persistent difficulty of disjunction“, In: A. Rojszczak, J. Cachro & G. Kurczewski (eds.), Philosophical dimensions of logic and science, Dordrecht, Springer, 77–90.