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The computational content of arithmetical proofs. (English) Zbl 1269.03055

Natural deductions in intuitionistic arithmetic have a unique normal form. This is not true for Gentzen-style sequent derivations, especially in classical arithmetic. Using a special redundancy construction from a previous work with M. Baaz, the author proves that for a wide class of arithmetical theories \(T\) the number of possible cut-free forms of a single arithmetical derivation in \(T\) of a \(\Sigma^0_1\)-formula is not bounded by any function provably recursive in \(T\).

MSC:

03F05 Cut-elimination and normal-form theorems
03F07 Structure of proofs
03F30 First-order arithmetic and fragments

References:

[1] Ackermann, W., “Zur Widerspruchsfreiheit der Zahlentheorie,” Mathematische Annalen , vol. 117 (1940), pp. 162-194. · Zbl 0022.29202 · doi:10.1007/BF01450016
[2] Avigad, J., “The computational content of classical arithmetic,” pp. 15-30 in Proofs, Categories, and Computations: Essays in Honor of Grigori Mints , edited by F. Solomon and S. Wilfried, vol. 13 of Tributes , College Publications, London, 2010. · Zbl 1244.03153
[3] Baaz, M., and S. Hetzl, “On the non-confluence of cut-elimination,” Journal of Symbolic Logic , vol. 76 (2011), pp. 313-340. · Zbl 1220.03048 · doi:10.2178/jsl/1294171002
[4] Baaz, M., S. Hetzl, A. Leitsch, C. Richter, and H. Spohr, “Cut-elimination: Experiments with CERES,” pp. 481-495 in Logic for Programming, Artificial Intelligence, and Reasoning , edited by F. Baader and A. Voronkov, vol. 3452 of Lecture Notes in Computer Science , Springer, Berlin, 2005. · Zbl 1108.03305 · doi:10.1007/b106931
[5] Friedman, H., “Classically and intuitionistically provable recursive functions,” pp. 21-27 in Higher Set Theory (Oberwolfach, 1977) , edited by G. H. Müller and D. S. Scott, vol. 669 of Lecture Notes in Mathematics , Springer, Berlin, 1978. · Zbl 0396.03045
[6] Gentzen, G., “Untersuchungen über das logische Schließen, I,” Mathematische Zeitschrift , vol. 39 (1935), pp. 176-210; “II,” pp. 405-431. · Zbl 0010.14601 · doi:10.1007/BF01201363
[7] Gentzen, G., “Die Widerspruchsfreiheit der reinen Zahlentheorie,” Mathematische Annalen , vol. 112 (1936), pp. 493-565. · Zbl 0014.38801 · doi:10.1007/BF01565428
[8] Girard, J.-Y., “Interprétation fonctionelle et élimination des coupures de l’arithmétique d’ordre supérieur,” Ph.D. thesis, Université Paris 7, 1972.
[9] Gödel, K., “Über eine bisher noch nicht benützte Erweiterung des finiten Standpunktes,” Dialectica , vol. 12 (1958), pp. 280-287. · Zbl 0090.01003 · doi:10.1111/j.1746-8361.1958.tb01464.x
[10] Hájek, P., and P. Pudlák, Metamathematics of First-Order Arithmetic , Perspectives in Mathematical Logic, Springer-Verlag, Berlin, 1998. · Zbl 0903.01017
[11] Kleene, S. C., “On the interpretation of intuitionistic number theory,” Journal of Symbolic Logic , vol. 10 (1945), pp. 109-124. · Zbl 0063.03260 · doi:10.2307/2269016
[12] Kohlenbach, U., Applied Proof Theory: Proof Interpretations and Their Use in Mathematics , Springer Monographs in Mathematics, Springer, Berlin, 2008. · Zbl 1158.03002 · doi:10.1007/978-3-540-77533-1
[13] Krajíček, J., “Interpolation theorems, lower bounds for proof systems, and independence results for bounded arithmetic,” Journal of Symbolic Logic , vol. 62 (1997), pp. 457-486. · Zbl 0891.03029 · doi:10.2307/2275541
[14] Kreisel, G., “On the interpretation of non-finitist proofs, II: Interpretation of number theory,” Journal of Symbolic Logic , vol. 17 (1952), pp. 43-58. · Zbl 0046.00701 · doi:10.2307/2267457
[15] Kreisel, G., “Finiteness theorems in arithmetic: An application of Herbrand’s theorem for \(\Sigma_{2}\)-formulas,” pp. 39-55, in Logic Colloquium ’81 ( Marseilles, 1981 ), edited by J. Stern, vol. 107 of Studies in Logic and the Foundations of Mathematics , North-Holland, Amsterdam, 1982. · Zbl 0499.03045
[16] Parigot, M., “\(\lambda\mu\)-Calculus: An algorithmic interpretation of classical natural deduction,” pp. 190-201, in Logic Programming and Automated Reasoning (St. Petersburg, 1992) , vol. 624 in Lecture Notes in Computer Science , Springer, Berlin, 1992. · Zbl 0925.03092 · doi:10.1007/BFb0013061
[17] Ratiu, D., and T. Trifonov, “Exploring the computational content of the infinite pigeonhole principle,” Journal of Logic and Computation , vol. 22 (2012), 329-350. · Zbl 1259.03072 · doi:10.1093/logcom/exq011
[18] Urban, C., and G. Bierman, “Strong normalisation of cut-elimination in classical logic,” Fundamenta Informaticae , vol. 45 (2000), pp. 123-155. · Zbl 0982.03032
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