Abstract
Akama et al. [1] introduced a hierarchical classification of first-order formulas for a hierarchical prenex normal form theorem in semi-classical arithmetic. In this paper, we give a justification for the hierarchical classification in a general context of first-order theories. To this end, we first formalize the standard transformation procedure for prenex normalization. Then we show that the classes \(\textrm{E}_k\) and \(\textrm{U}_k\) introduced in [1] are exactly the classes induced by \(\Sigma _k\) and \(\Pi _k\) respectively via the transformation procedure in any first-order theory.
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References
Akama, Y., Berardi, S., Hayashi, S., Kohlenbach, U.: An arithmetical hierarchy of the law of excluded middle and related principles. In: Proceedings of the 19th Annual IEEE Symposium on Logic in Computer Science (LICS’04), pp. 192–201 (2004). https://doi.org/10.1109/LICS.2004.1319613
Enderton, H.B.: A Mathematical Introduction to Logic. Elsevier Science, Amsterdam (2001)
Shoenfield, J.R.: Mathematical Logic. Taylor & Francis, Abingdon (2001)
Mints, G.E.: Solvability of the problem of deducibility in LJ for a class of formulas not containing negative occurrences of quantifiers. In: Steklov Inst, vol. 98, pp. 135–145 (1968)
Schubert, A., Urzyczyn, P., Zdanowski, K.: On the Mints hierarchy in first-order intuitionistic logic. Log. Methods Comput. Sci. (2017). https://doi.org/10.2168/LMCS-12(4:11)2016
Fleischmann, J.: Syntactic preservation theorems for intuitionistic predicate logic. Notre Dame J. Formal Log. 51(2), 225–245 (2010). https://doi.org/10.1215/00294527-2010-014
Burr, W.: Fragments of Heyting arithmetic. J. Symbol. Log. 65(3), 1223–1240 (2000). https://doi.org/10.2307/2586698
Leivant, D.: Implicational complexity in intuitionistic arithmetic. J. Symbol. Log. 46(2), 240–248 (1981). https://doi.org/10.2307/2273617
Brock-Nannestad, T., Ilik, D.: An intuitionistic formula hierarchy based on high-school identities. Math. Log. Q. 65(1), 57–79 (2019). https://doi.org/10.1002/malq.201700047
Fujiwara, M., Kurahashi, T.: Prenex normal form theorems in semi-classical arithmetic. J. Symbol. Log. 86(3), 1124–1153 (2021). https://doi.org/10.1017/jsl.2021.47
Fujiwara, M., Kurahashi, T.: Conservation theorems on semi-classical arithmetic. J. Symbol. Log. 88(4), 1469–1496 (2023). https://doi.org/10.1017/jsl.2022.25
Chang, C.C., Keisler, H.J.: Model Theory. Dover Books on Mathematics, 3rd edn. Dover Publications, NewYork (2013)
Boolos, G.: The Logic of Provability. Cambridge University Press, Cambridge (1993)
Acknowledgements
The authors thank Ulrich Kohlenbach for pointing them out that the definition of \(\textrm{P}_0\) in [1] is different from that in its preprint version, to which the authors referred in the previous version of this paper. They also thank Danko Ilik for providing some information about related works. The first author was supported by JSPS KAKENHI Grant Numbers JP19J01239, JP20K14354 and JP23K03205, and the second author by JP19K14586 and JP23K03200.
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Fujiwara, M., Kurahashi, T. Prenex normalization and the hierarchical classification of formulas. Arch. Math. Logic 63, 391–403 (2024). https://doi.org/10.1007/s00153-023-00899-x
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DOI: https://doi.org/10.1007/s00153-023-00899-x