Abstract
Multi-valued functions are common in computable analysis (built upon the Type 2 Theory of Effectivity), and have made an appearance in complexity theory under the moniker search problems leading to complexity classes such as \(\textrm{PPAD}\) and \(\textrm{PLS}\) being studied. However, a systematic investigation of the resulting degree structures has only been initiated in the former situation so far (the Weihrauch-degrees).
A more general understanding is possible, if the category-theoretic properties of multi-valued functions are taken into account. In the present paper, the category-theoretic framework is established, and it is demonstrated that many-one degrees of multi-valued functions form a distributive lattice under very general conditions, regardless of the actual reducibility notions used (e.g., Cook, Karp, Weihrauch).
Beyond this, an abundance of open questions arises. Some classic results for reductions between functions carry over to multi-valued functions, but others do not. The basic theme here again depends on category-theoretic differences between functions and multi-valued functions.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
References
Ambos-Spies, K.: Minimal pairs for polynomial time reducibilities. In: Börger, E. (ed.) Computation Theory and Logic. LNCS, vol. 270, pp. 1–13. Springer, Heidelberg (1987)
Brattka, V., de Brecht, M., Pauly, A.: Closed choice and a uniform low basis theorem. Annals of Pure and Applied Logic (2012)
Brattka, V., Gherardi, G.: Effective choice and boundedness principles in computable analysis. Journal of Symbolic Logic 76, 143–176 (2011) arXiv:0905.4685
Brattka, V., Gherardi, G.: Weihrauch degrees, omniscience principles and weak computability. Bulletin of Symbolic Logic 17, 73–117 (2011) arXiv:0905.4679
Brattka, V., Gherardi, G., Marcone, A.: The Bolzano-Weierstrass Theorem is the jump of Weak König’s Lemma. Annals of Pure and Applied Logic 163(6), 623–655 (2012)
Brattka, V., le Roux, S., Pauly, A.: On the Computational Content of the Brouwer Fixed Point Theorem. In: Cooper, S.B., Dawar, A., Löwe, B. (eds.) CiE 2012. LNCS, vol. 7318, pp. 57–68. Springer, Heidelberg (2012)
Chen, X., Deng, X.: Settling the complexity of 2-player Nash-equilibrium. Tech. Rep. 134, Electronic Colloquium on Computational Complexity (2005)
Daskalakis, C., Papadimitriou, C.: Continuous local search. In: Proceedings of SODA (2011)
Di Paola, R., Heller, A.: Dominical categories: Recursion theory without elements. Journal of Symbolic Logic 52, 594–635 (1987)
Gherardi, G., Marcone, A.: How incomputable is the separable Hahn-Banach theorem? Notre Dame Journal of Formal Logic 50(4), 393–425 (2009)
Higuchi, K., Pauly, A.: The degree-structure of Weihrauch-reducibility. arXiv 1101.0112 (2011)
Johnson, D.S., Papadimtriou, C.H., Yannakakis, M.: How easy is local search? Journal of Computer and System Sciences 37(1), 79–100 (1988)
Ladner, R.E.: On the structure of polynomial time reducibility. Journal of the ACM 22(1), 155–171 (1975)
Papadimitriou, C.H.: On the complexity of the parity argument and other inefficient proofs of existence. Journal of Computer and Systems Science 48(3), 498–532 (1994)
Pauly, A.: How incomputable is finding Nash equilibria? Journal of Universal Computer Science 16(18), 2686–2710 (2010)
Pauly, A.: On the (semi)lattices induced by continuous reducibilities. Mathematical Logic Quarterly 56(5), 488–502 (2010)
Pauly, A.: Many-one reductions between search problems. arXiv 1102.3151 (2011)
Pauly, A.: Computable Metamathematics and its Application to Game Theory. Ph.D. thesis, University of Cambridge (2012)
Robinson, E., Rosolini, G.: Categories of partial maps. Information and Computation 79(2), 95–130 (1988)
Weihrauch, K.: The degrees of discontinuity of some translators between representations of the real numbers. Informatik Berichte 129, FernUniversität Hagen, Hagen (July 1992)
Weihrauch, K.: The TTE-interpretation of three hierarchies of omniscience principles. Informatik Berichte 130, FernUniversität Hagen, Hagen (September 1992)
Yates, C.E.M.: A minimal pair of recursively enumerable degrees. The Journal of Symbolic Logic 31(2), 159–168 (1966)
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2012 Springer-Verlag Berlin Heidelberg
About this paper
Cite this paper
Pauly, A. (2012). Multi-valued Functions in Computability Theory. In: Cooper, S.B., Dawar, A., Löwe, B. (eds) How the World Computes. CiE 2012. Lecture Notes in Computer Science, vol 7318. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-30870-3_57
Download citation
DOI: https://doi.org/10.1007/978-3-642-30870-3_57
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-642-30869-7
Online ISBN: 978-3-642-30870-3
eBook Packages: Computer ScienceComputer Science (R0)