Abstract
We present axiomatizations of the two main set theories: the Theory of Types and Zermelo-Fraenkel Set Theory. We present some basic facts about the arithmetic of infinite cardinal and ordinal numbers. We introduce the concept of large cardinals, which are cardinal numbers whose existence is not provable from the axioms of Zermelo-Fraenkel Set Theory, and present some applications of axioms postulating the existence of large cardinals. We discuss two important, but slightly controversial axioms: the Axiom of Choice and the Axiom of Determinacy. In the last section we present Quine’s version of the type theory and two approaches based on non-standard analysis.
Meaning! Listen to the mathematician talk. Great space, man, what has mathematics to do with meaning? Mathematics is a tool and as long as it can be manipulated to give proper answers and to make correct predictions, actual meaning has no significance.
Isaac Asimov, The Imaginary
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Notes
- 1.
In English: Basic Laws of Arithmetic.
- 2.
More precisely, we have only to worry about the variables that are quantified, as they talk about the ‘totality of all sets of a given order’, while parameters do not matter, as they talk about particular elements.
- 3.
Item No. AB.1.1165.
- 4.
Even if it were complete, it would not guarantee that there was a unique model.
- 5.
Book 10, Proposition 20 [117].
- 6.
Born and lived in the Kingdom of Bohemia.
- 7.
The history of the invention of the diagonal argument is not quite clear. Some historians attribute the idea to Paul du Bois-Reymond.
- 8.
See also Theorem 2 on page 41.
- 9.
I am using the standard convention that \(x^{y^{z}}\) means x raised to the power y z; it should not be confused with (x y)z which is equal to x yz.
- 10.
In theories without the Axiom of Foundation we have to add explicitly that the elements of α are well-ordered by the membership relation ∈.
- 11.
The explanation of the game by Kenneth Kunen is a little different: “…to try to completely demolish your ego by transcending your number via some completely new principle”, [172] page 396.
- 12.
Recall that in fact the ordinal ω α and the cardinal ℵ α are represented by the same set.
- 13.
More precisely, it is consistent with ZFC to assume that it is.
- 14.
More precisely, he defined an interpretation of the axioms of ZFC in the theory without the Axiom of Choice.
- 15.
More precisely, either one player has a winning strategy, or both players have strategies that guarantee them to win or to tie.
- 16.
I am using he for the first player and she for the second.
- 17.
See [147], page 132.
- 18.
S. Shelah proved that even if we only want the Lebesgue measurability, the inaccessible cardinal is needed [266].
- 19.
Note, however, that nonstandard analysis uses models, whereas here we are talking about a theory.
- 20.
An important exception is high energy physics. Physicist hope to discover new particles by using more powerful accelerators.
- 21.
However, experimental computations with natural numbers are perhaps as old as mathematics itself.
- 22.
See page 212.
- 23.
See page 175.
- 24.
It is not clear that the two numbers can be ∗ π and π; to this end one would have to prove that the strings 222090721 and 17012003 occur infinitely often in the decimal expansion of π.
References
Banach, S., Tarski, A.: Sur la décomposition des ensembles de points en parties respectivement congruentes. Fundam. Math. 6, 244–277 (1924)
Barwise, J.: Admissible Sets and Structures: An Approach to Definability Theory. Springer, Berlin (1975)
Bernstein, A., Robinson, A.: Solution of an invariant subspace problem of K.T. Smith and P.R. Halmos. Pac. J. Math. 16(3), 421–431 (1966)
Bachmann, H.: Die Normalfunktionen und das Problem der ausgezeichneten Folgen von Ordnungszahlen. Vierteljschr. Naturforsch. Ges. Zürich 95, 115–147 (1950)
Bernays, P.: A system of axiomatic set theory I. J. Symb. Log. 2, 65–77 (1937)
Bolzano, B.: Paradoxien des Unendlichen. C.H. Reclam, Leipzig (1951)
Boolos, G.: Logic, Logic, and Logic. Harvard University Press, Cambridge (1998)
Cantor, G.: Über eine elementare Frage der Mannigfaltigkeitslehre. Jahresbericht der Deutsch. Math. Vereing. I, 75–78 (1890/91)
Cohen, P.: Set Theory and the Continuum Hypothesis, Benjamin, New York (1963)
Dehornoy, P.: Braid groups and left distributive operations. Trans. Am. Math. Soc. 345(1), 115–150 (1994)
Fraenkel, A.A.: Zu den Grundlagen der Cantor-Zermeloschen Mengenlehre. Math. Ann. 86, 230–237 (1922)
Frege, G.: Grundgesetze der Arithmetik I. Hermann Pohle, Jena (1893)
Frege, G.: Grundgesetze der Arithmetik II. Hermann Pohle, Jena (1903)
Galilei, G.: Discorsi e dimostrazioni matematiche intorno a due nuove scienze attinenti la mecanica e i movimenti locali. Elzevir, Leiden (1638)
Gödel, K.: The Consistency of the Axiom of Choice and of the Generalized Continuum Hypothesis with the Axioms of Set Theory. Annals of Mathematical Studies, vol. 3. Princeton University Press, Princeton (1940)
Gödel, K.: What is Cantor’s continuum problem? Am. Math. Mon. 54(9), 515–525 (1947)
Heath, T.L.: The Thirteen Books of Euclid’s Elements. Cambridge University Press, Cambridge (1908)
Hilbert, D.: Mathematical problems. Bull. Am. Math. Soc. 8, 437–479 (1902)
Hirschfeld, J.: The nonstandard treatment of Hilbert’s fifth problem. Trans. Am. Math. Soc. 321(1), 379–400 (1990)
Jech, T.: OTTER experiments in a system of combinatory logic. J. Autom. Reason. 14(3), 413–426 (1995)
Jensen, R.B.: On the consistency of a slight(?) modification of Quine’s NF. Synthese 19, 250–263 (1969)
Kanamori, A.: The Higher Infinite, Large Cardinals in Set Theory from Their Beginnings. Springer, Berlin (1994)
Kunen, K.: Combinatorics. In: Barwise, J. (ed.) Handbook of Mathematical Logic. North-Holland, Amsterdam (1977)
Laczkovich, M.: Conjecture and Proof. TypoTeX, Budapest (1998)
Laver, R.: The left-distributive law and the freeness of an algebra of elementary embeddings. Adv. Math. 91, 209–231 (1992)
Laver, R.: On the algebra of elementary embeddings of a rank into itself. Adv. Math. 110, 334–346 (1995)
Lawvere, F.W.: An elementary theory of the category of sets. Proc. Natl. Acad. Sci. USA 52, 1506–1511 (1964)
Mac Lane, S., Moerdijk, I.: Sheaves in Geometry and Logic: A First Introduction to Topos Theory. Springer, New York (1992)
McCarthy, C.: What does it take to prove Fermat’s Last Theorem? Grothendieck and the logic of number theory. Bull. Symb. Log. 16(3), 359–377 (2010)
Mycielski, J., Steinhaus, H.: A mathematical axiom contradicting the axiom of choice. Bull. Acad. Pol. Sci., Sér. Sci. Math. Astron. Phys. 10, 1–3 (1962)
von Neumann, J.: Eine Axiomatisierung der Mengenlehre. J. Reine Angew. Math. 154, 219–240 (1925)
Quine, W.V.: New foundations for mathematical logic. Am. Math. Mon. 44, 70–80 (1937)
Rathjen, M.: The higher infinite in proof theory. In: Makowsky, J., Ravve, E. (eds.) Logic Colloquium ’95. Springer Lecture Notes in Logic, vol. 11, pp. 275–304 (1998)
Robinson, A.: Non-standard Analysis. North-Holland, Amsterdam (1966)
Rosser, J.B.: Logic for Mathematicians. McGraw-Hill, New York (1953)
Russell, B.: The Principles of Mathematics. Cambridge University Press, Cambridge (1903)
Russell, B.: Mathematical logic as based on the theory of types. Am. J. Math. 30, 222–262 (1908)
Scott, D.: Measurable cardinals and constructible sets. Bull. Acad. Pol. Sci. 9, 521–524 (1961)
Shelah, S.: Can you take Solovay’s inaccessible away? Isr. J. Math. 48(1), 1–47 (1984)
Skolem, T.: Einige Bemerkungen zur axiomatischen Begründung der Mengenlehre. In: Fünften Kongress der Skandinavischen Mathematiker in Helsingfors 1922. Helsingfors, pp. 217–232 (1923)
Solovay, R.M.: A model of set-theory in which every set of reals is Lebesgue measurable. Ann. Math. 92(1), 1–56 (1970)
Solovay, R.M.: Real valued measurable cardinals. In: Scott, D.S. (ed.) Axiomatic Set Theory. Proc. Sym. in Pure Math. XIII, vol. 1, pp. 387–428 (1971)
Specker, E.P.: Dualität. Dialectica 12, 451–465 (1958)
Vopěnka, P.: Mathematics in the Alternative Set Theory. Teubner, Leipzig (1979)
Wang, H.: The formalization of mathematics. J. Symb. Log. 19, 241–266 (1954)
Wang, H.: A Survey of Mathematical Logic. Science Press, Peking (1962)
Woodin, W.H.: The Axiom of Determinacy, Forcing Axioms, and the Nonstationary Ideal. de Gruyter, Berlin (1999)
Whitehead, A.N., Russell, B.: Principia Mathematica, I. Cambridge University Press, Cambridge (1910)
Whitehead, A.N., Russell, B.: Principia Mathematica, II. Cambridge University Press, Cambridge (1912)
Whitehead, A.N., Russell, B.: Principia Mathematica, III. Cambridge University Press, Cambridge (1913)
Zermelo, E.: Beweis, dass jede Menge wohlgeordnet werden kann. Math. Ann. 59(4), 514–516 (1904)
Zermelo, E.: Untersuchungen über die Grundlagen der Mengenlehre. I. Math. Ann. 65, 261–281 (1908)
Zermelo, E.: Über Grenzzahlen und Mengenbereiche. Fundam. Math. 16, 29–47 (1930)
Author information
Authors and Affiliations
Main Points of the Chapter
Main Points of the Chapter
-
The two major axiomatic systems for set theory are Bertrand Russell’s Theory of Types and Zermelo-Fraenkel Set Theory. Today the latter one is accepted by most mathematicians as a theory describing the true universe of sets.
-
Though based on different ideas, the Theory of Types and Zermelo Set Theory, a basic part of Zermelo-Fraenkel Set Theory, are essentially the same. Zermelo-Fraenkel set theory is conceptually simpler, it is stronger, and it can be naturally extended to much stronger systems.
-
Infinite sets are defined as sets satisfying a certain property that is not satisfied by finite sets.
-
In Zermelo-Fraenkel Set Theory there are infinitely many different infinite cardinalities and there is no largest one.
-
The cardinality of the real numbers is bigger than the cardinality of natural numbers, but we do not know, and, maybe, never will, whether there are other infinite cardinalities in between.
-
Large cardinal axioms are new axioms that serve to make Zermelo-Fraenkel Set Theory stronger. Using these axioms we can decide some important statements that are undecidable in pure Zermelo-Fraenkel Set Theory.
-
The problem with such axioms is that the stronger they are the greater the danger is that they are inconsistent. There is no way to secure their consistency; we can only rely on experience that a lot of research has been done and no contradiction has been found.
-
The Axiom of Choice has some consequences which look paradoxical, but it does not introduce an inconsistency into Zermelo-Fraenkel Set Theory.
-
It is possible to replace the Axiom of Choice by axioms that make sets of real numbers look better. In particular, it is consistent to assume that all subsets of the real numbers are measurable, provided that we abandon the unrestricted Axiom of Choice and use only its weaker version.
-
The particular set of axioms that we are using may be the result of a historical accident. It is conceivable that if the Axiom of Determinacy had been discovered before the Axiom of Choice, it may have become the preferred one.
-
Various other axiom systems for set theory have been proposed, but only the Zermelo-Fraenkel system has been accepted by working mathematicians. A likely reason is that it is the strongest available theory.
-
New Foundations is an interesting system because we still do not know whether it is consistent. More precisely, we do not have proof of contradiction in the system, nor are we able to prove its consistency using Zermelo-Fraenkel Set Theory (even with the help of large cardinal axioms).
-
Nonstandard analysis offers a different way of developing the foundations of calculus and in some cases has helped solve open problems.
Rights and permissions
Copyright information
© 2013 Springer International Publishing Switzerland
About this chapter
Cite this chapter
Pudlák, P. (2013). Set Theory. In: Logical Foundations of Mathematics and Computational Complexity. Springer Monographs in Mathematics. Springer, Heidelberg. https://doi.org/10.1007/978-3-319-00119-7_3
Download citation
DOI: https://doi.org/10.1007/978-3-319-00119-7_3
Publisher Name: Springer, Heidelberg
Print ISBN: 978-3-319-00118-0
Online ISBN: 978-3-319-00119-7
eBook Packages: Mathematics and StatisticsMathematics and Statistics (R0)