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Continuum hypothesis

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6758: 4410: 321:, the existence of a bijection between two sets becomes more difficult to demonstrate. The rational numbers seemingly form a counterexample to the continuum hypothesis: the integers form a proper subset of the rationals, which themselves form a proper subset of the reals, so intuitively, there are more rational numbers than integers and more real numbers than rational numbers. However, this intuitive analysis is flawed; it does not take proper account of the fact that all three sets are 4320: 2969: 2551: 970:, and it was later supported by the independence of CH from the axioms of ZFC since these axioms are enough to establish the elementary properties of sets and cardinalities. In order to argue against this viewpoint, it would be sufficient to demonstrate new axioms that are supported by intuition and resolve CH in one direction or another. Although the 1660:(the axiom that every set is constructible relative to the ordinals), and is therefore consistent with ZFC. As GCH implies CH, Cohen's model in which CH fails is a model in which GCH fails, and thus GCH is not provable from ZFC. W. B. Easton used the method of forcing developed by Cohen to prove 977:
At least two other axioms have been proposed that have implications for the continuum hypothesis, although these axioms have not currently found wide acceptance in the mathematical community. In 1986, Chris Freiling presented an argument against CH by showing that the negation of CH is equivalent to
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proved in 1940 that the negation of the continuum hypothesis, i.e., the existence of a set with intermediate cardinality, could not be proved in standard set theory. The second half of the independence of the continuum hypothesis – i.e., unprovability of the nonexistence of an intermediate-sized set
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The independence from ZFC means that proving or disproving the CH within ZFC is impossible. However, Gödel and Cohen's negative results are not universally accepted as disposing of all interest in the continuum hypothesis. The continuum hypothesis remains an active topic of research; see
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approach to set theory and argues that "the continuum hypothesis is settled on the multiverse view by our extensive knowledge about how it behaves in the multiverse, and, as a result, it can no longer be settled in the manner formerly hoped for". In a related vein,
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wrote that he does "not agree with the pure Platonic view that the interesting problems in set theory can be decided, that we just have to discover the additional axiom. My mental picture is that we have many possible set theories, all conforming to ZFC".
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were among the first genuinely mathematical statements shown to be independent of ZF set theory. Although the existence of some statements independent of ZFC had already been known more than two decades prior: for example, assuming
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of ZFC, so that either the continuum hypothesis or its negation can be added as an axiom to ZFC set theory, with the resulting theory being consistent if and only if ZFC is consistent. This independence was proved in 1963 by
2546:{\displaystyle \aleph _{\alpha }^{\aleph _{\beta }}\leq \aleph _{\beta +1}^{\aleph _{\beta }}=(2^{\aleph _{\beta }})^{\aleph _{\beta }}=2^{\aleph _{\beta }\cdot \aleph _{\beta }}=2^{\aleph _{\beta }}=\aleph _{\beta +1}} 352:). His proofs, however, give no indication of the extent to which the cardinality of the integers is less than that of the real numbers. Cantor proposed the continuum hypothesis as a possible solution to this question. 2695: 2354: 2226: 2294: 2104: 2166: 502: 1648: 2703: 3637: 1527:, AD), so choice and GCH are not independent in ZF; there are no models of ZF in which GCH holds and AC fails. To prove this, Sierpiński showed GCH implies that every cardinality n is smaller than some 1742: 1385: 2035: 1329: 1460: 421: 847: 611: 148: 1790: 1936: 1988: 1853: 746: 1133: 192: 1689: 1569: 1246: 1205: 807: 355:
The continuum hypothesis states that the set of real numbers has minimal possible cardinality which is greater than the cardinality of the set of integers. That is, every set,
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Although the generalized continuum hypothesis refers directly only to cardinal exponentiation with 2 as the base, one can deduce from it the values of cardinal exponentiation
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For any infinite sets A and B, if there is an injection from A to B then there is an injection from subsets of A to subsets of B. Thus for any infinite cardinals A and B,
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can actually be used to argue in favor of CH, because among models that have the same reals, models with "more" sets of reals have a better chance of satisfying CH.
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th successor of κ. On the other hand, László Patai proved that if γ is an ordinal and for each infinite cardinal κ, 2 is the γth successor of κ, then γ is finite.
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Another viewpoint is that the conception of set is not specific enough to determine whether CH is true or false. This viewpoint was advanced as early as 1923 by
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of ZF set theory, assuming only the axioms of ZF. The existence of an inner model of ZF in which additional axioms hold shows that the additional axioms are
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Cohen showed that CH cannot be proven from the ZFC axioms, completing the overall independence proof. To prove his result, Cohen developed the method of
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argued that CH is not a definite mathematical problem. He proposed a theory of "definiteness" using a semi-intuitionistic subsystem of ZF that accepts
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of sets were against CH, while those favoring a "neat" and "controllable" universe favored CH. Parallel arguments were made for and against the
6962: 3728: 684:. A result of Solovay, proved shortly after Cohen's result on the independence of the continuum hypothesis, shows that in any model of ZFC, if 2241: 1062:, thus falsifying CH. The Star axiom was bolstered by an independent May 2021 proof showing the Star axiom can be derived from a variation of 2051: 2119: 435: 5895: 5036: 1066:. However, Woodin stated in the 2010s that he now instead believes CH to be true, based on his belief in his new "ultimate L" conjecture. 920:
scheme) expressing the consistency of ZFC, that is also independent of it. The latter independence result indeed holds for many theories.
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The independence proof just described shows that CH is independent of ZFC. Further research has shown that CH is independent of all known
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Cantor believed the continuum hypothesis to be true and for many years tried in vain to prove it. It became the first on David Hilbert's
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and therefore had no problems with asserting the truth and falsehood of statements independent of their provability. Cohen, though a
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Proceedings of Symposia in Pure Mathematics XXVIII, F. Browder, editor. American Mathematical Society, 1976, pp. 81–92.
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does resolve CH, it is not generally considered to be intuitively true any more than CH is generally considered to be false.
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holds. GCH implies that this strict, stronger inequality holds for infinite cardinals as well as finite cardinals.
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does not reject Woodin's argument outright but urges caution. Woodin proposed a new hypothesis that he labeled the
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Rittberg, Colin J. (March 2015). "How Woodin changed his mind: new thoughts on the Continuum Hypothesis".
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Gödel believed that CH is false, and that his proof that CH is consistent with ZFC only shows that the
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and vice versa. Hence, the set {banana, apple, pear} has the same cardinality as {yellow, red, green}.
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with ZF, provided ZF itself is consistent. The latter condition cannot be proved in ZF itself, due to
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Hamkins, Joel David (January 2015). "Is the Dream Solution of the Continuum Hypothesis Attainable?".
1657: 1004: 971: 948: 916:, which were published in 1931, establish that there is a formal statement (one for each appropriate 751: 5194: 6579: 6509: 6048: 5900: 5883: 5606: 5086: 4369: 3363: 6411: 6388: 6349: 6235: 6176: 5822: 5742: 5586: 5530: 5143: 4988: 4906: 4781: 4733: 4547: 4470: 1146: 1038: 937: 542: 515: 3107: 2626:{\displaystyle \aleph _{\beta +1}=2^{\aleph _{\beta }}\leq \aleph _{\alpha }^{\aleph _{\beta }}} 6701: 6428: 6406: 6373: 6266: 6112: 6097: 6070: 6021: 5905: 5840: 5665: 5631: 5626: 5500: 5331: 5308: 4940: 4821: 4633: 4446: 3358: 1516: 1485: 956: 944: 641: 223: 30:
This article is about the hypothesis in set theory. For the assumption in fluid mechanics, see
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Moore, Gregory H. (2011). "Early history of the generalized continuum hypothesis: 1878–1938".
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Freiling, Chris (1986). "Axioms of Symmetry: Throwing darts at the real number line".
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proved that (assuming the consistency of very large cardinals) it is consistent that
4120: 3965: 3905: 3622: 3434: 3398: 3225:"The Consistency of the Axiom of Choice and of the Generalized Continuum-Hypothesis" 6711: 6706: 6599: 6556: 6378: 6339: 6334: 6319: 6145: 6102: 5999: 5797: 5747: 5321: 5283: 4993: 4983: 4968: 4963: 4831: 4485: 4176: 4100: 4046: 4004: 3977: 3950: 3938: 3893: 3814: 3788: 3702: 3649: 3602: 3507: 3368: 3321: 3303: 3254: 3244: 3173: 3155: 3043: 1069: 3942: 909: 640:(AC) is adopted (making ZFC). Gödel's proof shows that CH and AC both hold in the 6692: 6682: 6636: 6619: 6574: 6536: 6438: 6358: 6165: 6092: 6065: 6053: 5959: 5873: 5847: 5802: 5770: 5571: 5373: 5316: 5266: 5231: 5189: 4862: 4800: 4618: 4431: 4217: 4108: 4079:
Merimovich, Carmi (2007). "A power function with a fixed finite gap everywhere".
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to have the same cardinality means that it is possible to "pair off" elements of
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Proceedings of the National Academy of Sciences of the United States of America
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Proceedings of the National Academy of Sciences of the United States of America
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This article incorporates material from Generalized continuum hypothesis on
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Martin, D. (1976). "Hilbert's first problem: the continuum hypothesis," in
3335: 3268: 3249: 3187: 3160: 3025: 2690:{\displaystyle \aleph _{\beta }\geq \operatorname {cf} (\aleph _{\alpha })} 2349:{\displaystyle \aleph _{\beta }\geq \operatorname {cf} (\aleph _{\alpha })} 1528: 1249: 664: 364: 322: 198: 100: 60: 3308: 2221:{\displaystyle \aleph _{\beta }<\operatorname {cf} (\aleph _{\alpha })} 1531:, and thus can be ordered. This is done by showing that n is smaller than 6661: 6541: 5720: 5710: 5657: 5341: 5261: 5246: 5126: 5071: 4978: 4613: 3638:"Throwing a dart at Freiling's argument against the continuum hypothesis" 2990: 2985: 1419: 1100:
is mathematically "definite" if the semi-intuitionistic theory can prove
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axioms do not adequately characterize the universe of sets. Gödel was a
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Feferman, Solomon (February 1999). "Does mathematics need new axioms?".
2289:{\displaystyle \aleph _{\alpha }^{\aleph _{\beta }}=\aleph _{\alpha +1}} 1664:, which shows it is consistent with ZFC for arbitrarily large cardinals 888:
in those fields have subsequently been shown to be independent as well.
5591: 5446: 5417: 5223: 4958: 4729: 4385: 4306:"How Many Numbers Exist? Infinity Proof Moves Math Closer to an Answer" 4204: 4188: 4058: 3755:"How Many Numbers Exist? Infinity Proof Moves Math Closer to an Answer" 3614: 3519: 3380: 2233: 2099:{\displaystyle \aleph _{\alpha }^{\aleph _{\beta }}=\aleph _{\beta +1}} 885: 705: 649: 48: 3470: 3284:"The independence of the Continuum Hypothesis, [part] II" 2995: 2161:{\displaystyle \aleph _{\alpha }^{\aleph _{\beta }}=\aleph _{\alpha }} 497:{\displaystyle \nexists S\colon \aleph _{0}<|S|<2^{\aleph _{0}}} 286:(a one-to-one correspondence) between them. Intuitively, for two sets 6743: 6646: 5699: 5616: 5576: 5540: 5476: 5288: 5278: 5251: 5014: 4761: 4724: 4675: 4573: 4345: 4095: 3933: 3653: 3317: 3169: 3136:"The independence of the Continuum Hypothesis, [part I]" 1172: 923: 566:, and the continuum hypothesis is in turn equivalent to the equality 283: 4180: 4157:. Columbus, Ohio: Charles E. Merrill. p. 147, exercise 76. 4050: 3606: 3511: 3372: 1879: ≥ 1, it is consistent with ZFC that for each κ, 2 is the 6728: 6526: 5974: 5679: 5273: 3498:
Goodman, Nicolas D. (1979). "Mathematics as an objective science".
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The continuum hypothesis is closely related to many statements in
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in 1878, and establishing its truth or falsehood is the first of
72: 1643:{\displaystyle 2^{\aleph _{0}+n}\,=\,2\cdot \,2^{\aleph _{0}+n}} 4786: 4608: 1482:. The continuum hypothesis is the special case for the ordinal 963: 748:. However, per König's theorem, it is not consistent to assume 3819:"Is the Continuum Hypothesis a definite mathematical problem?" 943:
Historically, mathematicians who favored a "rich" and "large"
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Gödel showed that CH cannot be disproved from ZF, even if the
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Mathematische und naturwissenschaftliche Berichte aus Ungarn
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Georg Cantor: His mathematics and philosophy of the infinite
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in the context of ZFC. Moreover, it has been shown that the
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Mathematical Developments Arising from Hilbert's Problems,
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has attracted considerable attention since the year 2000.
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Cantor gave two proofs that the cardinality of the set of
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Maddy, Penelope (June 1988). "Believing the axioms, ".
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The independence of the continuum hypothesis (CH) from
423:, the continuum hypothesis can be restated as follows: 99:(ZFC), this is equivalent to the following equation in 4134:
Patai, L. (1930). "Untersuchungen über die א-reihe".
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for unbounded ones, and suggested that a proposition
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provide an alternative notation for this condition:
884:. As a result of its independence, many substantial 1324:{\displaystyle \lambda <\kappa <2^{\lambda }} 1158: 1139:wrote a critical commentary on Feferman's article. 1001:, or "Star axiom". The Star axiom would imply that 4303: 4273:, reprinted in Benacerraf and Putnam's collection 4146: 3566:Set Theory: An Introduction to Independence Proofs 3099: 2963: 2781: 2689: 2625: 2545: 2348: 2288: 2220: 2160: 2098: 2029: 1982: 1930: 1867: 1847: 1804: 1784: 1736: 1683: 1642: 1563: 1500: 1474: 1455:{\displaystyle \aleph _{\alpha }=\beth _{\alpha }} 1454: 1402: 1379: 1323: 1284: 1264: 1240: 1199: 1127: 1092: 1054: 1027: 924:Arguments for and against the continuum hypothesis 861: 841: 801: 774: 740: 696: 605: 558: 531: 496: 415: 186: 142: 3342: 3060:: CS1 maint: DOI inactive as of September 2024 ( 1938:. If A and B are finite, the stronger inequality 205:presented in 1900. The answer to this problem is 6944: 4209:Creative Commons Attribution/Share-Alike License 900:for an overview of the current research status. 6802: 3588: 3586: 3229:Proceedings of the National Academy of Sciences 3035:Journal für die Reine und Angewandte Mathematik 1994:Implications of GCH for cardinal exponentiation 259: 221:The name of the hypothesis comes from the term 4237:. Mineola, New York City: Dover Publications. 4175:(2). Association for Symbolic Logic: 481–511. 4152: 4072: 3601:(1). Association for Symbolic Logic: 190–200. 3428: 3426: 3091: 416:{\displaystyle |\mathbb {R} |=2^{\aleph _{0}}} 59:) is a hypothesis about the possible sizes of 6788: 5030: 4370: 3921:Bulletin of the American Mathematical Society 3839: 3635: 3569:. Amsterdam, NL: North-Holland. p. 171. 3553: 3459: 3392: 3390: 3199: 3197: 1515:Like CH, GCH is also independent of ZFC, but 1211:, then it has the same cardinality as either 989:A difficult argument against CH developed by 842:{\displaystyle \aleph _{\omega _{1}+\omega }} 708:, then there is a forcing extension in which 512:, there is a unique smallest cardinal number 4254:An Introduction to Independence for Analysts 3957: 3807: 3722:"Has the Continuum Hypothesis been settled?" 3583: 2037:in all cases. GCH implies that for ordinals 340:is strictly smaller than that of the set of 4251: 4153:Hayden, Seymour; Kennison, John F. (1968). 4023: 3864: 3746: 3713: 3676: 3491: 3423: 3129: 3127: 3085:The Consistency of the Continuum-Hypothesis 3075: 3073: 3071: 1512:. For the early history of GCH, see Moore. 606:{\displaystyle 2^{\aleph _{0}}=\aleph _{1}} 143:{\displaystyle 2^{\aleph _{0}}=\aleph _{1}} 6795: 6781: 5222: 5037: 5023: 4377: 4363: 4294: 4078: 3919:Shelah, Saharon (2003). "Logical dreams". 3912: 3387: 3194: 1785:{\displaystyle 2^{\kappa }>\kappa ^{+}} 306:is paired off with exactly one element of 4127: 4094: 3988: 3932: 3887: 3752: 3696: 3362: 3325: 3307: 3258: 3248: 3177: 3159: 3018: 1931:{\displaystyle A<B\to 2^{A}\leq 2^{B}} 1875:. Carmi Merimovich showed that, for each 1656:showed that GCH is a consequence of ZF + 1616: 1609: 1605: 384: 197:The continuum hypothesis was advanced by 34:. For the album by Epoch of Unlight, see 4260: 3963: 3874:(2012). "The set-theoretic multiverse". 3845: 3813: 3778: 3629: 3592: 3465: 3435:"The Continuum Hypothesis, Part II" 3348: 3275: 3124: 3068: 3030:"Ein Beitrag zur Mannigfaltigkeitslehre" 1983:{\displaystyle A<B\to 2^{A}<2^{B}} 1848:{\displaystyle 2^{\kappa }=\kappa ^{++}} 1523:(AC) (and therefore the negation of the 616: 329:) as the set of integers: they are both 302:in such a fashion that every element of 241:International Congress of Mathematicians 4235:Set theory and the continuum hypothesis 4029: 3870: 3826:Exploring the Frontiers of Independence 3719: 3682: 3497: 3478:Exploring the Frontiers of Independence 3399:"The Continuum Hypothesis, Part I" 3203: 3106:. Princeton University Press. pp.  741:{\displaystyle 2^{\aleph _{0}}=\kappa } 247:was at that point not yet formulated. 14: 6945: 5044: 3918: 3848:"Feferman on the indefiniteness of CH" 3432: 3396: 3097: 3024: 1128:{\displaystyle (\phi \lor \neg \phi )} 313:With infinite sets such as the set of 187:{\displaystyle \beth _{1}=\aleph _{1}} 6963:Basic concepts in infinite set theory 6776: 5018: 4358: 4332: 4229: 4166: 4133: 3994: 3781:Archive for History of Exact Sciences 3559: 3547: 3281: 3222: 3133: 3079: 940:, also tended towards rejecting CH. 680:can be any cardinal consistent with 4304:Wolchover, Natalie (15 July 2021). 4271:What is Cantor's Continuum Problem? 3753:Wolchover, Natalie (15 July 2021). 3134:Cohen, Paul J. (15 December 1963). 1650:; for the full proof, see Gillman. 951:, which implies CH. More recently, 625:(ZF) follows from combined work of 346:Cantor's first uncountability proof 270:Two sets are said to have the same 24: 4252:Dales, H.G.; Woodin, W.H. (1987). 4223: 3685:Notre Dame Journal of Formal Logic 3282:Cohen, Paul J. (15 January 1964). 2946: 2931: 2911: 2898: 2878: 2861: 2838: 2828: 2813: 2803: 2770: 2752: 2733: 2718: 2708: 2675: 2653: 2612: 2602: 2587: 2563: 2528: 2513: 2493: 2480: 2460: 2443: 2420: 2404: 2389: 2379: 2334: 2312: 2271: 2256: 2246: 2206: 2184: 2149: 2134: 2124: 2081: 2066: 2056: 2016: 2006: 1792:holds for every infinite cardinal 1719: 1704: 1672: 1623: 1588: 1544: 1430: 1366: 1342: 1224: 1183: 1116: 1043: 1014: 817: 790: 761: 721: 594: 579: 547: 520: 483: 449: 402: 175: 131: 116: 25: 6994: 4313: 3500:The American Mathematical Monthly 1684:{\displaystyle \aleph _{\alpha }} 1564:{\displaystyle 2^{\aleph _{0}+n}} 1519:proved that ZF + GCH implies the 1241:{\displaystyle {\mathcal {P}}(S)} 1200:{\displaystyle {\mathcal {P}}(S)} 1076:for bounded quantifiers but uses 903:The continuum hypothesis and the 802:{\displaystyle \aleph _{\omega }} 27:Proposition in mathematical logic 6756: 4408: 4318: 4068:from the original on 2022-10-10. 3860:from the original on 2012-03-19. 3835:from the original on 2022-10-10. 3487:from the original on 2012-01-24. 3455:from the original on 2022-10-10. 3419:from the original on 2022-10-10. 1165:generalized continuum hypothesis 1159:Generalized continuum hypothesis 849:or any cardinal with cofinality 237:list of important open questions 214:, complementing earlier work by 71:is strictly between that of the 36:The Continuum Hypothesis (album) 18:Generalized Continuum Hypothesis 3772: 3734:from the original on 2022-10-10 1028:{\displaystyle 2^{\aleph _{0}}} 914:Gödel's incompleteness theorems 775:{\displaystyle 2^{\aleph _{0}}} 654:Gödel's incompleteness theorems 4384: 4207:, which is licensed under the 3964:Jourdain, Philip E.B. (1905). 3216: 3098:Dauben, Joseph Warren (1990). 2873: 2852: 2761: 2748: 2684: 2671: 2455: 2434: 2343: 2330: 2215: 2202: 1954: 1902: 1571:which is smaller than its own 1235: 1229: 1194: 1188: 1122: 1107: 470: 462: 389: 379: 13: 1: 6717:History of mathematical logic 4039:American Mathematical Monthly 3943:10.1090/s0273-0979-03-00981-9 3351:American Mathematical Monthly 3087:. Princeton University Press. 3011: 1508:. GCH was first suggested by 704:is a cardinal of uncountable 6642:Primitive recursive function 3876:The Review of Symbolic Logic 980:Freiling's axiom of symmetry 678:cardinality of the continuum 260:Cardinality of infinite sets 7: 4155:Zermelo-Fraenkel Set Theory 3001:Second continuum hypothesis 2974: 1055:{\displaystyle \aleph _{2}} 623:Zermelo–Fraenkel set theory 559:{\displaystyle \aleph _{0}} 532:{\displaystyle \aleph _{1}} 243:in the year 1900 in Paris. 93:Zermelo–Fraenkel set theory 10: 6999: 5706:Schröder–Bernstein theorem 5433:Monadic predicate calculus 5092:Foundations of mathematics 4875:von Neumann–Bernays–Gödel 4297:"The Continuum Hypothesis" 4261:Enderton, Herbert (1977). 4196: 3997:Bulletin of Symbolic Logic 3828:. Harvard lecture series. 3636:Bagemihl, F. (1989–1990). 3532:This view is often called 3480:. Harvard lecture series. 3471:"The Continuum Hypothesis" 363:. As the real numbers are 350:Cantor's diagonal argument 263: 239:that was presented at the 230: 203:Hilbert's 23 problems 29: 6810: 6752: 6739:Philosophy of mathematics 6688:Automated theorem proving 6670: 6565: 6397: 6290: 6142: 5859: 5835: 5813:Von Neumann–Bernays–Gödel 5758: 5652: 5556: 5454: 5445: 5372: 5307: 5213: 5135: 5052: 4939: 4902: 4814: 4704: 4676:One-to-one correspondence 4592: 4533: 4417: 4406: 4392: 4275:Philosophy of Mathematics 4169:Journal of Symbolic Logic 4082:Journal of Symbolic Logic 4030:Gillman, Leonard (2002). 3982:10.1080/14786440509463254 3898:10.1017/S1755020311000359 3793:10.1007/s00407-014-0142-8 3595:Journal of Symbolic Logic 2637:The third equality (when 2360:The first equality (when 1501:{\displaystyle \alpha =1} 1412:Cantor's aleph hypothesis 972:axiom of constructibility 949:axiom of constructibility 912:and the consistency ZFC, 910:good soundness properties 3846:Koellner, Peter (2011). 3707:10.1215/00294527-2835047 3433:Woodin, W. Hugh (2001). 3397:Woodin, W. Hugh (2001). 3048:10.1515/crll.1878.84.242 1575:—this uses the equality 1331:. GCH is equivalent to: 1265:{\displaystyle \lambda } 252:– was proved in 1963 by 6389:Self-verifying theories 6210:Tarski's axiomatization 5161:Tarski's undefinability 5156:incompleteness theorems 3204:Goldrei, Derek (1996). 1868:{\displaystyle \kappa } 1805:{\displaystyle \kappa } 1475:{\displaystyle \alpha } 1403:{\displaystyle \alpha } 1285:{\displaystyle \kappa } 862:{\displaystyle \omega } 697:{\displaystyle \kappa } 667:in 1966 for his proof. 150:, or even shorter with 67:"There is no set whose 6763:Mathematics portal 6374:Proof of impossibility 6022:propositional variable 5332:Propositional calculus 4634:Constructible universe 4454:Constructibility (V=L) 4341:"Continuum Hypothesis" 4323:Quotations related to 4263:Elements of Set Theory 4105:10.2178/jsl/1185803615 4009:10.2178/bsl/1318855631 3970:Philosophical Magazine 3720:Foreman, Matt (2003). 3642:Real Analysis Exchange 3250:10.1073/pnas.24.12.556 3161:10.1073/pnas.50.6.1143 3050:(inactive 2024-09-11). 2965: 2783: 2691: 2627: 2547: 2350: 2290: 2222: 2162: 2100: 2031: 1984: 1932: 1869: 1849: 1806: 1786: 1738: 1685: 1644: 1565: 1502: 1476: 1456: 1404: 1381: 1325: 1286: 1266: 1242: 1201: 1129: 1094: 1056: 1029: 957:ontological maximalism 863: 843: 803: 776: 742: 698: 642:constructible universe 607: 560: 533: 498: 417: 371:of the integers, i.e. 227:for the real numbers. 188: 144: 89: 81: 6953:Forcing (mathematics) 6632:Kolmogorov complexity 6585:Computably enumerable 6485:Model complete theory 6277:Principia Mathematica 5337:Propositional formula 5166:Banach–Tarski paradox 4857:Principia Mathematica 4691:Transfinite induction 4550:(i.e. set difference) 3309:10.1073/pnas.51.1.105 2966: 2784: 2692: 2628: 2548: 2351: 2291: 2223: 2163: 2101: 2032: 1985: 1933: 1870: 1850: 1807: 1787: 1739: 1686: 1645: 1566: 1503: 1477: 1457: 1410:(occasionally called 1405: 1382: 1326: 1287: 1272:there is no cardinal 1267: 1243: 1202: 1130: 1095: 1093:{\displaystyle \phi } 1057: 1030: 955:has pointed out that 864: 844: 804: 777: 743: 699: 673:large cardinal axioms 617:Independence from ZFC 608: 561: 534: 499: 418: 189: 145: 85: 65: 6958:Independence results 6580:Church–Turing thesis 6567:Computability theory 5776:continuum hypothesis 5294:Square of opposition 5152:Gödel's completeness 4931:Burali-Forti paradox 4686:Set-builder notation 4639:Continuum hypothesis 4579:Symmetric difference 4325:Continuum hypothesis 3223:Gödel, Kurt (1938). 2799: 2704: 2649: 2559: 2375: 2308: 2242: 2180: 2120: 2052: 2002: 1942: 1890: 1859: 1816: 1796: 1756: 1695: 1668: 1579: 1535: 1525:axiom of determinacy 1486: 1466: 1426: 1394: 1338: 1296: 1276: 1256: 1219: 1178: 1104: 1084: 1078:intuitionistic logic 1039: 1005: 853: 813: 786: 752: 712: 688: 570: 543: 516: 436: 428:Continuum hypothesis 375: 245:Axiomatic set theory 158: 107: 53:continuum hypothesis 32:Continuum assumption 6734:Mathematical object 6625:P versus NP problem 6590:Computable function 6384:Reverse mathematics 6310:Logical consequence 6187:primitive recursive 6182:elementary function 5955:Free/bound variable 5808:Tarski–Grothendieck 5327:Logical connectives 5257:Logical equivalence 5107:Logical consequence 4892:Tarski–Grothendieck 3872:Hamkins, Joel David 3300:1964PNAS...51..105C 3241:1938PNAS...24..556G 3152:1963PNAS...50.1143C 2848: 2823: 2765: 2728: 2622: 2430: 2399: 2266: 2144: 2076: 2026: 1691:to fail to satisfy 1248:. That is, for any 431: —  6968:Hilbert's problems 6804:Hilbert's problems 6532:Transfer principle 6495:Semantics of logic 6480:Categorical theory 6456:Non-standard model 5970:Logical connective 5097:Information theory 5046:Mathematical logic 4481:Limitation of size 4338:Weisstein, Eric W. 4231:Cohen, Paul Joseph 4216:2017-02-08 at the 3442:Notices of the AMS 3406:Notices of the AMS 3210:Chapman & Hall 3206:Classic Set Theory 2961: 2827: 2802: 2779: 2732: 2707: 2687: 2623: 2601: 2543: 2403: 2378: 2368:+1) follows from: 2346: 2286: 2245: 2218: 2158: 2123: 2096: 2055: 2027: 2005: 1980: 1928: 1865: 1845: 1802: 1782: 1734: 1681: 1640: 1561: 1498: 1472: 1462:for every ordinal 1452: 1400: 1377: 1321: 1282: 1262: 1238: 1197: 1143:Joel David Hamkins 1125: 1090: 1052: 1025: 859: 839: 799: 772: 738: 694: 603: 556: 529: 494: 429: 413: 282:if there exists a 184: 140: 6940: 6939: 6770: 6769: 6702:Abstract category 6505:Theories of truth 6315:Rule of inference 6305:Natural deduction 6286: 6285: 5831: 5830: 5536:Cartesian product 5441: 5440: 5347:Many-valued logic 5322:Boolean functions 5205:Russell's paradox 5180:diagonal argument 5077:First-order logic 5012: 5011: 4921:Russell's paradox 4870:Zermelo–Fraenkel 4771:Dedekind-infinite 4644:Diagonal argument 4543:Cartesian product 4400:Set (mathematics) 4265:. Academic Press. 4244:978-0-486-46921-8 3972:. Series 6. 3815:Feferman, Solomon 3576:978-0-444-85401-8 2981:Absolute infinite 427: 298:with elements of 83:Or equivalently: 16:(Redirected from 6990: 6983:Cardinal numbers 6797: 6790: 6783: 6774: 6773: 6761: 6760: 6712:History of logic 6707:Category of sets 6600:Decision problem 6379:Ordinal analysis 6320:Sequent calculus 6218:Boolean algebras 6158: 6157: 6132: 6103:logical/constant 5857: 5856: 5843: 5766:Zermelo–Fraenkel 5517:Set operations: 5452: 5451: 5389: 5220: 5219: 5200:Löwenheim–Skolem 5087:Formal semantics 5039: 5032: 5025: 5016: 5015: 4994:Bertrand Russell 4984:John von Neumann 4969:Abraham Fraenkel 4964:Richard Dedekind 4926:Suslin's problem 4837:Cantor's theorem 4554:De Morgan's laws 4412: 4379: 4372: 4365: 4356: 4355: 4351: 4350: 4334:Szudzik, Matthew 4322: 4309: 4300: 4295:McGough, Nancy. 4266: 4257: 4248: 4192: 4159: 4158: 4150: 4144: 4143: 4131: 4125: 4124: 4098: 4076: 4070: 4069: 4067: 4036: 4027: 4021: 4020: 3992: 3986: 3985: 3961: 3955: 3954: 3936: 3916: 3910: 3909: 3891: 3868: 3862: 3861: 3859: 3852: 3843: 3837: 3836: 3834: 3823: 3811: 3805: 3804: 3776: 3770: 3769: 3767: 3765: 3750: 3744: 3743: 3741: 3739: 3733: 3726: 3717: 3711: 3710: 3700: 3680: 3674: 3673: 3654:10.2307/44152014 3633: 3627: 3626: 3590: 3581: 3580: 3557: 3551: 3545: 3539: 3538: 3495: 3489: 3488: 3486: 3475: 3463: 3457: 3456: 3454: 3439: 3430: 3421: 3420: 3418: 3403: 3394: 3385: 3384: 3366: 3346: 3340: 3339: 3329: 3311: 3279: 3273: 3272: 3262: 3252: 3220: 3214: 3213: 3201: 3192: 3191: 3181: 3163: 3146:(6): 1143–1148. 3131: 3122: 3121: 3105: 3095: 3089: 3088: 3077: 3066: 3065: 3059: 3051: 3022: 3006:Wetzel's problem 2970: 2968: 2967: 2962: 2960: 2959: 2941: 2940: 2939: 2938: 2921: 2920: 2919: 2918: 2906: 2905: 2888: 2887: 2886: 2885: 2871: 2870: 2869: 2868: 2847: 2846: 2845: 2835: 2822: 2821: 2820: 2810: 2788: 2786: 2785: 2780: 2778: 2777: 2764: 2760: 2759: 2740: 2727: 2726: 2725: 2715: 2697:) follows from: 2696: 2694: 2693: 2688: 2683: 2682: 2661: 2660: 2632: 2630: 2629: 2624: 2621: 2620: 2619: 2609: 2597: 2596: 2595: 2594: 2577: 2576: 2552: 2550: 2549: 2544: 2542: 2541: 2523: 2522: 2521: 2520: 2503: 2502: 2501: 2500: 2488: 2487: 2470: 2469: 2468: 2467: 2453: 2452: 2451: 2450: 2429: 2428: 2427: 2417: 2398: 2397: 2396: 2386: 2355: 2353: 2352: 2347: 2342: 2341: 2320: 2319: 2295: 2293: 2292: 2287: 2285: 2284: 2265: 2264: 2263: 2253: 2227: 2225: 2224: 2219: 2214: 2213: 2192: 2191: 2167: 2165: 2164: 2159: 2157: 2156: 2143: 2142: 2141: 2131: 2105: 2103: 2102: 2097: 2095: 2094: 2075: 2074: 2073: 2063: 2036: 2034: 2033: 2028: 2025: 2024: 2023: 2013: 1989: 1987: 1986: 1981: 1979: 1978: 1966: 1965: 1937: 1935: 1934: 1929: 1927: 1926: 1914: 1913: 1874: 1872: 1871: 1866: 1854: 1852: 1851: 1846: 1844: 1843: 1828: 1827: 1811: 1809: 1808: 1803: 1791: 1789: 1788: 1783: 1781: 1780: 1768: 1767: 1743: 1741: 1740: 1735: 1733: 1732: 1714: 1713: 1712: 1711: 1690: 1688: 1687: 1682: 1680: 1679: 1662:Easton's theorem 1649: 1647: 1646: 1641: 1639: 1638: 1631: 1630: 1604: 1603: 1596: 1595: 1570: 1568: 1567: 1562: 1560: 1559: 1552: 1551: 1507: 1505: 1504: 1499: 1481: 1479: 1478: 1473: 1461: 1459: 1458: 1453: 1451: 1450: 1438: 1437: 1409: 1407: 1406: 1401: 1386: 1384: 1383: 1378: 1376: 1375: 1374: 1373: 1356: 1355: 1330: 1328: 1327: 1322: 1320: 1319: 1291: 1289: 1288: 1283: 1271: 1269: 1268: 1263: 1247: 1245: 1244: 1239: 1228: 1227: 1206: 1204: 1203: 1198: 1187: 1186: 1171:and that of the 1134: 1132: 1131: 1126: 1099: 1097: 1096: 1091: 1070:Solomon Feferman 1064:Martin's maximum 1061: 1059: 1058: 1053: 1051: 1050: 1034: 1032: 1031: 1026: 1024: 1023: 1022: 1021: 1000: 968:Skolem's paradox 930:Zermelo–Fraenkel 868: 866: 865: 860: 848: 846: 845: 840: 838: 837: 830: 829: 808: 806: 805: 800: 798: 797: 781: 779: 778: 773: 771: 770: 769: 768: 747: 745: 744: 739: 731: 730: 729: 728: 703: 701: 700: 695: 612: 610: 609: 604: 602: 601: 589: 588: 587: 586: 565: 563: 562: 557: 555: 554: 538: 536: 535: 530: 528: 527: 503: 501: 500: 495: 493: 492: 491: 490: 473: 465: 457: 456: 432: 422: 420: 419: 414: 412: 411: 410: 409: 392: 387: 382: 319:rational numbers 193: 191: 190: 185: 183: 182: 170: 169: 149: 147: 146: 141: 139: 138: 126: 125: 124: 123: 21: 6998: 6997: 6993: 6992: 6991: 6989: 6988: 6987: 6943: 6942: 6941: 6936: 6806: 6801: 6771: 6766: 6755: 6748: 6693:Category theory 6683:Algebraic logic 6666: 6637:Lambda calculus 6575:Church encoding 6561: 6537:Truth predicate 6393: 6359:Complete theory 6282: 6151: 6147: 6143: 6138: 6130: 5850: and  5846: 5841: 5827: 5803:New Foundations 5771:axiom of choice 5754: 5716:Gödel numbering 5656: and  5648: 5552: 5437: 5387: 5368: 5317:Boolean algebra 5303: 5267:Equiconsistency 5232:Classical logic 5209: 5190:Halting problem 5178: and  5154: and  5142: and  5141: 5136:Theorems ( 5131: 5048: 5043: 5013: 5008: 4935: 4914: 4898: 4863:New Foundations 4810: 4700: 4619:Cardinal number 4602: 4588: 4529: 4413: 4404: 4388: 4383: 4316: 4245: 4226: 4224:Further reading 4218:Wayback Machine 4199: 4181:10.2307/2274520 4163: 4162: 4151: 4147: 4132: 4128: 4077: 4073: 4065: 4051:10.2307/2695444 4034: 4028: 4024: 3993: 3989: 3962: 3958: 3917: 3913: 3869: 3865: 3857: 3850: 3844: 3840: 3832: 3821: 3812: 3808: 3777: 3773: 3763: 3761: 3759:Quanta Magazine 3751: 3747: 3737: 3735: 3731: 3724: 3718: 3714: 3681: 3677: 3634: 3630: 3607:10.2307/2273955 3591: 3584: 3577: 3558: 3554: 3546: 3542: 3512:10.2307/2320581 3496: 3492: 3484: 3473: 3467:Koellner, Peter 3464: 3460: 3452: 3437: 3431: 3424: 3416: 3401: 3395: 3388: 3373:10.2307/2589047 3347: 3343: 3280: 3276: 3235:(12): 556–557. 3221: 3217: 3202: 3195: 3132: 3125: 3118: 3096: 3092: 3078: 3069: 3053: 3052: 3042:(84): 242–258. 3023: 3019: 3014: 2977: 2949: 2945: 2934: 2930: 2929: 2925: 2914: 2910: 2901: 2897: 2896: 2892: 2881: 2877: 2876: 2872: 2864: 2860: 2859: 2855: 2841: 2837: 2836: 2831: 2816: 2812: 2811: 2806: 2800: 2797: 2796: 2791:König's theorem 2773: 2769: 2755: 2751: 2741: 2736: 2721: 2717: 2716: 2711: 2705: 2702: 2701: 2678: 2674: 2656: 2652: 2650: 2647: 2646: 2615: 2611: 2610: 2605: 2590: 2586: 2585: 2581: 2566: 2562: 2560: 2557: 2556: 2531: 2527: 2516: 2512: 2511: 2507: 2496: 2492: 2483: 2479: 2478: 2474: 2463: 2459: 2458: 2454: 2446: 2442: 2441: 2437: 2423: 2419: 2418: 2407: 2392: 2388: 2387: 2382: 2376: 2373: 2372: 2337: 2333: 2315: 2311: 2309: 2306: 2305: 2274: 2270: 2259: 2255: 2254: 2249: 2243: 2240: 2239: 2209: 2205: 2187: 2183: 2181: 2178: 2177: 2152: 2148: 2137: 2133: 2132: 2127: 2121: 2118: 2117: 2084: 2080: 2069: 2065: 2064: 2059: 2053: 2050: 2049: 2019: 2015: 2014: 2009: 2003: 2000: 1999: 1996: 1974: 1970: 1961: 1957: 1943: 1940: 1939: 1922: 1918: 1909: 1905: 1891: 1888: 1887: 1860: 1857: 1856: 1836: 1832: 1823: 1819: 1817: 1814: 1813: 1797: 1794: 1793: 1776: 1772: 1763: 1759: 1757: 1754: 1753: 1722: 1718: 1707: 1703: 1702: 1698: 1696: 1693: 1692: 1675: 1671: 1669: 1666: 1665: 1626: 1622: 1621: 1617: 1591: 1587: 1586: 1582: 1580: 1577: 1576: 1547: 1543: 1542: 1538: 1536: 1533: 1532: 1521:axiom of choice 1510:Philip Jourdain 1487: 1484: 1483: 1467: 1464: 1463: 1446: 1442: 1433: 1429: 1427: 1424: 1423: 1395: 1392: 1391: 1369: 1365: 1364: 1360: 1345: 1341: 1339: 1336: 1335: 1315: 1311: 1297: 1294: 1293: 1277: 1274: 1273: 1257: 1254: 1253: 1223: 1222: 1220: 1217: 1216: 1182: 1181: 1179: 1176: 1175: 1161: 1105: 1102: 1101: 1085: 1082: 1081: 1074:classical logic 1046: 1042: 1040: 1037: 1036: 1017: 1013: 1012: 1008: 1006: 1003: 1002: 998: 953:Matthew Foreman 926: 918:Gödel numbering 905:axiom of choice 854: 851: 850: 825: 821: 820: 816: 814: 811: 810: 793: 789: 787: 784: 783: 764: 760: 759: 755: 753: 750: 749: 724: 720: 719: 715: 713: 710: 709: 689: 686: 685: 682:König's theorem 638:axiom of choice 619: 597: 593: 582: 578: 577: 573: 571: 568: 567: 550: 546: 544: 541: 540: 523: 519: 517: 514: 513: 510:axiom of choice 506: 486: 482: 481: 477: 469: 461: 452: 448: 437: 434: 433: 430: 405: 401: 400: 396: 388: 383: 378: 376: 373: 372: 279:cardinal number 268: 266:Cardinal number 262: 233: 178: 174: 165: 161: 159: 156: 155: 134: 130: 119: 115: 114: 110: 108: 105: 104: 97:axiom of choice 47:, specifically 39: 28: 23: 22: 15: 12: 11: 5: 6996: 6986: 6985: 6980: 6975: 6970: 6965: 6960: 6955: 6938: 6937: 6935: 6934: 6927: 6922: 6917: 6912: 6907: 6902: 6897: 6892: 6887: 6882: 6877: 6872: 6867: 6862: 6857: 6852: 6847: 6842: 6837: 6832: 6827: 6822: 6817: 6811: 6808: 6807: 6800: 6799: 6792: 6785: 6777: 6768: 6767: 6753: 6750: 6749: 6747: 6746: 6741: 6736: 6731: 6726: 6725: 6724: 6714: 6709: 6704: 6695: 6690: 6685: 6680: 6678:Abstract logic 6674: 6672: 6668: 6667: 6665: 6664: 6659: 6657:Turing machine 6654: 6649: 6644: 6639: 6634: 6629: 6628: 6627: 6622: 6617: 6612: 6607: 6597: 6595:Computable set 6592: 6587: 6582: 6577: 6571: 6569: 6563: 6562: 6560: 6559: 6554: 6549: 6544: 6539: 6534: 6529: 6524: 6523: 6522: 6517: 6512: 6502: 6497: 6492: 6490:Satisfiability 6487: 6482: 6477: 6476: 6475: 6465: 6464: 6463: 6453: 6452: 6451: 6446: 6441: 6436: 6431: 6421: 6420: 6419: 6414: 6407:Interpretation 6403: 6401: 6395: 6394: 6392: 6391: 6386: 6381: 6376: 6371: 6361: 6356: 6355: 6354: 6353: 6352: 6342: 6337: 6327: 6322: 6317: 6312: 6307: 6302: 6296: 6294: 6288: 6287: 6284: 6283: 6281: 6280: 6272: 6271: 6270: 6269: 6264: 6263: 6262: 6257: 6252: 6232: 6231: 6230: 6228:minimal axioms 6225: 6214: 6213: 6212: 6201: 6200: 6199: 6194: 6189: 6184: 6179: 6174: 6161: 6159: 6140: 6139: 6137: 6136: 6135: 6134: 6122: 6117: 6116: 6115: 6110: 6105: 6100: 6090: 6085: 6080: 6075: 6074: 6073: 6068: 6058: 6057: 6056: 6051: 6046: 6041: 6031: 6026: 6025: 6024: 6019: 6014: 6004: 6003: 6002: 5997: 5992: 5987: 5982: 5977: 5967: 5962: 5957: 5952: 5951: 5950: 5945: 5940: 5935: 5925: 5920: 5918:Formation rule 5915: 5910: 5909: 5908: 5903: 5893: 5892: 5891: 5881: 5876: 5871: 5866: 5860: 5854: 5837:Formal systems 5833: 5832: 5829: 5828: 5826: 5825: 5820: 5815: 5810: 5805: 5800: 5795: 5790: 5785: 5780: 5779: 5778: 5773: 5762: 5760: 5756: 5755: 5753: 5752: 5751: 5750: 5740: 5735: 5734: 5733: 5726:Large cardinal 5723: 5718: 5713: 5708: 5703: 5689: 5688: 5687: 5682: 5677: 5662: 5660: 5650: 5649: 5647: 5646: 5645: 5644: 5639: 5634: 5624: 5619: 5614: 5609: 5604: 5599: 5594: 5589: 5584: 5579: 5574: 5569: 5563: 5561: 5554: 5553: 5551: 5550: 5549: 5548: 5543: 5538: 5533: 5528: 5523: 5515: 5514: 5513: 5508: 5498: 5493: 5491:Extensionality 5488: 5486:Ordinal number 5483: 5473: 5468: 5467: 5466: 5455: 5449: 5443: 5442: 5439: 5438: 5436: 5435: 5430: 5425: 5420: 5415: 5410: 5405: 5404: 5403: 5393: 5392: 5391: 5378: 5376: 5370: 5369: 5367: 5366: 5365: 5364: 5359: 5354: 5344: 5339: 5334: 5329: 5324: 5319: 5313: 5311: 5305: 5304: 5302: 5301: 5296: 5291: 5286: 5281: 5276: 5271: 5270: 5269: 5259: 5254: 5249: 5244: 5239: 5234: 5228: 5226: 5217: 5211: 5210: 5208: 5207: 5202: 5197: 5192: 5187: 5182: 5170:Cantor's  5168: 5163: 5158: 5148: 5146: 5133: 5132: 5130: 5129: 5124: 5119: 5114: 5109: 5104: 5099: 5094: 5089: 5084: 5079: 5074: 5069: 5068: 5067: 5056: 5054: 5050: 5049: 5042: 5041: 5034: 5027: 5019: 5010: 5009: 5007: 5006: 5001: 4999:Thoralf Skolem 4996: 4991: 4986: 4981: 4976: 4971: 4966: 4961: 4956: 4951: 4945: 4943: 4937: 4936: 4934: 4933: 4928: 4923: 4917: 4915: 4913: 4912: 4909: 4903: 4900: 4899: 4897: 4896: 4895: 4894: 4889: 4884: 4883: 4882: 4867: 4866: 4865: 4853: 4852: 4851: 4840: 4839: 4834: 4829: 4824: 4818: 4816: 4812: 4811: 4809: 4808: 4803: 4798: 4793: 4784: 4779: 4774: 4764: 4759: 4758: 4757: 4752: 4747: 4737: 4727: 4722: 4717: 4711: 4709: 4702: 4701: 4699: 4698: 4693: 4688: 4683: 4681:Ordinal number 4678: 4673: 4668: 4663: 4662: 4661: 4656: 4646: 4641: 4636: 4631: 4626: 4616: 4611: 4605: 4603: 4601: 4600: 4597: 4593: 4590: 4589: 4587: 4586: 4581: 4576: 4571: 4566: 4561: 4559:Disjoint union 4556: 4551: 4545: 4539: 4537: 4531: 4530: 4528: 4527: 4526: 4525: 4520: 4509: 4508: 4506:Martin's axiom 4503: 4498: 4493: 4488: 4483: 4478: 4473: 4471:Extensionality 4468: 4467: 4466: 4456: 4451: 4450: 4449: 4444: 4439: 4429: 4423: 4421: 4415: 4414: 4407: 4405: 4403: 4402: 4396: 4394: 4390: 4389: 4382: 4381: 4374: 4367: 4359: 4353: 4352: 4315: 4314:External links 4312: 4311: 4310: 4301: 4292: 4278: 4267: 4258: 4249: 4243: 4225: 4222: 4221: 4220: 4198: 4195: 4194: 4193: 4161: 4160: 4145: 4126: 4089:(2): 361–417. 4071: 4045:(6): 544–553. 4022: 4003:(4): 489–532. 3987: 3956: 3927:(2): 203–228. 3923:. New Series. 3911: 3882:(3): 416–449. 3863: 3838: 3806: 3787:(2): 125–151. 3771: 3745: 3712: 3675: 3648:(1): 342–345. 3628: 3582: 3575: 3561:Kunen, Kenneth 3552: 3550:, p. 500. 3540: 3506:(7): 540–551. 3490: 3458: 3448:(7): 681–690. 3422: 3412:(6): 567–576. 3386: 3341: 3294:(1): 105–110. 3274: 3215: 3193: 3123: 3116: 3090: 3067: 3016: 3015: 3013: 3010: 3009: 3008: 3003: 2998: 2993: 2988: 2983: 2976: 2973: 2972: 2971: 2958: 2955: 2952: 2948: 2944: 2937: 2933: 2928: 2924: 2917: 2913: 2909: 2904: 2900: 2895: 2891: 2884: 2880: 2875: 2867: 2863: 2858: 2854: 2851: 2844: 2840: 2834: 2830: 2826: 2819: 2815: 2809: 2805: 2794: 2776: 2772: 2768: 2763: 2758: 2754: 2750: 2747: 2744: 2739: 2735: 2731: 2724: 2720: 2714: 2710: 2686: 2681: 2677: 2673: 2670: 2667: 2664: 2659: 2655: 2635: 2634: 2618: 2614: 2608: 2604: 2600: 2593: 2589: 2584: 2580: 2575: 2572: 2569: 2565: 2554: 2540: 2537: 2534: 2530: 2526: 2519: 2515: 2510: 2506: 2499: 2495: 2491: 2486: 2482: 2477: 2473: 2466: 2462: 2457: 2449: 2445: 2440: 2436: 2433: 2426: 2422: 2416: 2413: 2410: 2406: 2402: 2395: 2391: 2385: 2381: 2358: 2357: 2345: 2340: 2336: 2332: 2329: 2326: 2323: 2318: 2314: 2283: 2280: 2277: 2273: 2269: 2262: 2258: 2252: 2248: 2237: 2236:operation; and 2217: 2212: 2208: 2204: 2201: 2198: 2195: 2190: 2186: 2155: 2151: 2147: 2140: 2136: 2130: 2126: 2115: 2093: 2090: 2087: 2083: 2079: 2072: 2068: 2062: 2058: 2022: 2018: 2012: 2008: 1995: 1992: 1977: 1973: 1969: 1964: 1960: 1956: 1953: 1950: 1947: 1925: 1921: 1917: 1912: 1908: 1904: 1901: 1898: 1895: 1864: 1842: 1839: 1835: 1831: 1826: 1822: 1801: 1779: 1775: 1771: 1766: 1762: 1744:. Much later, 1731: 1728: 1725: 1721: 1717: 1710: 1706: 1701: 1678: 1674: 1637: 1634: 1629: 1625: 1620: 1615: 1612: 1608: 1602: 1599: 1594: 1590: 1585: 1573:Hartogs number 1558: 1555: 1550: 1546: 1541: 1497: 1494: 1491: 1471: 1449: 1445: 1441: 1436: 1432: 1416: 1415: 1399: 1372: 1368: 1363: 1359: 1354: 1351: 1348: 1344: 1318: 1314: 1310: 1307: 1304: 1301: 1281: 1261: 1237: 1234: 1231: 1226: 1196: 1193: 1190: 1185: 1160: 1157: 1152:Saharon Shelah 1137:Peter Koellner 1124: 1121: 1118: 1115: 1112: 1109: 1089: 1049: 1045: 1020: 1016: 1011: 991:W. Hugh Woodin 925: 922: 898:Peter Koellner 882:measure theory 858: 836: 833: 828: 824: 819: 796: 792: 767: 763: 758: 737: 734: 727: 723: 718: 693: 618: 615: 600: 596: 592: 585: 581: 576: 553: 549: 526: 522: 489: 485: 480: 476: 472: 468: 464: 460: 455: 451: 447: 444: 441: 425: 408: 404: 399: 395: 391: 386: 381: 331:countable sets 264:Main article: 261: 258: 232: 229: 181: 177: 173: 168: 164: 137: 133: 129: 122: 118: 113: 26: 9: 6: 4: 3: 2: 6995: 6984: 6981: 6979: 6976: 6974: 6971: 6969: 6966: 6964: 6961: 6959: 6956: 6954: 6951: 6950: 6948: 6932: 6928: 6926: 6923: 6921: 6918: 6916: 6913: 6911: 6908: 6906: 6903: 6901: 6898: 6896: 6893: 6891: 6888: 6886: 6883: 6881: 6878: 6876: 6873: 6871: 6868: 6866: 6863: 6861: 6858: 6856: 6853: 6851: 6848: 6846: 6843: 6841: 6838: 6836: 6833: 6831: 6828: 6826: 6823: 6821: 6818: 6816: 6813: 6812: 6809: 6805: 6798: 6793: 6791: 6786: 6784: 6779: 6778: 6775: 6765: 6764: 6759: 6751: 6745: 6742: 6740: 6737: 6735: 6732: 6730: 6727: 6723: 6720: 6719: 6718: 6715: 6713: 6710: 6708: 6705: 6703: 6699: 6696: 6694: 6691: 6689: 6686: 6684: 6681: 6679: 6676: 6675: 6673: 6669: 6663: 6660: 6658: 6655: 6653: 6652:Recursive set 6650: 6648: 6645: 6643: 6640: 6638: 6635: 6633: 6630: 6626: 6623: 6621: 6618: 6616: 6613: 6611: 6608: 6606: 6603: 6602: 6601: 6598: 6596: 6593: 6591: 6588: 6586: 6583: 6581: 6578: 6576: 6573: 6572: 6570: 6568: 6564: 6558: 6555: 6553: 6550: 6548: 6545: 6543: 6540: 6538: 6535: 6533: 6530: 6528: 6525: 6521: 6518: 6516: 6513: 6511: 6508: 6507: 6506: 6503: 6501: 6498: 6496: 6493: 6491: 6488: 6486: 6483: 6481: 6478: 6474: 6471: 6470: 6469: 6466: 6462: 6461:of arithmetic 6459: 6458: 6457: 6454: 6450: 6447: 6445: 6442: 6440: 6437: 6435: 6432: 6430: 6427: 6426: 6425: 6422: 6418: 6415: 6413: 6410: 6409: 6408: 6405: 6404: 6402: 6400: 6396: 6390: 6387: 6385: 6382: 6380: 6377: 6375: 6372: 6369: 6368:from ZFC 6365: 6362: 6360: 6357: 6351: 6348: 6347: 6346: 6343: 6341: 6338: 6336: 6333: 6332: 6331: 6328: 6326: 6323: 6321: 6318: 6316: 6313: 6311: 6308: 6306: 6303: 6301: 6298: 6297: 6295: 6293: 6289: 6279: 6278: 6274: 6273: 6268: 6267:non-Euclidean 6265: 6261: 6258: 6256: 6253: 6251: 6250: 6246: 6245: 6243: 6240: 6239: 6237: 6233: 6229: 6226: 6224: 6221: 6220: 6219: 6215: 6211: 6208: 6207: 6206: 6202: 6198: 6195: 6193: 6190: 6188: 6185: 6183: 6180: 6178: 6175: 6173: 6170: 6169: 6167: 6163: 6162: 6160: 6155: 6149: 6144:Example  6141: 6133: 6128: 6127: 6126: 6123: 6121: 6118: 6114: 6111: 6109: 6106: 6104: 6101: 6099: 6096: 6095: 6094: 6091: 6089: 6086: 6084: 6081: 6079: 6076: 6072: 6069: 6067: 6064: 6063: 6062: 6059: 6055: 6052: 6050: 6047: 6045: 6042: 6040: 6037: 6036: 6035: 6032: 6030: 6027: 6023: 6020: 6018: 6015: 6013: 6010: 6009: 6008: 6005: 6001: 5998: 5996: 5993: 5991: 5988: 5986: 5983: 5981: 5978: 5976: 5973: 5972: 5971: 5968: 5966: 5963: 5961: 5958: 5956: 5953: 5949: 5946: 5944: 5941: 5939: 5936: 5934: 5931: 5930: 5929: 5926: 5924: 5921: 5919: 5916: 5914: 5911: 5907: 5904: 5902: 5901:by definition 5899: 5898: 5897: 5894: 5890: 5887: 5886: 5885: 5882: 5880: 5877: 5875: 5872: 5870: 5867: 5865: 5862: 5861: 5858: 5855: 5853: 5849: 5844: 5838: 5834: 5824: 5821: 5819: 5816: 5814: 5811: 5809: 5806: 5804: 5801: 5799: 5796: 5794: 5791: 5789: 5788:Kripke–Platek 5786: 5784: 5781: 5777: 5774: 5772: 5769: 5768: 5767: 5764: 5763: 5761: 5757: 5749: 5746: 5745: 5744: 5741: 5739: 5736: 5732: 5729: 5728: 5727: 5724: 5722: 5719: 5717: 5714: 5712: 5709: 5707: 5704: 5701: 5697: 5693: 5690: 5686: 5683: 5681: 5678: 5676: 5673: 5672: 5671: 5667: 5664: 5663: 5661: 5659: 5655: 5651: 5643: 5640: 5638: 5635: 5633: 5632:constructible 5630: 5629: 5628: 5625: 5623: 5620: 5618: 5615: 5613: 5610: 5608: 5605: 5603: 5600: 5598: 5595: 5593: 5590: 5588: 5585: 5583: 5580: 5578: 5575: 5573: 5570: 5568: 5565: 5564: 5562: 5560: 5555: 5547: 5544: 5542: 5539: 5537: 5534: 5532: 5529: 5527: 5524: 5522: 5519: 5518: 5516: 5512: 5509: 5507: 5504: 5503: 5502: 5499: 5497: 5494: 5492: 5489: 5487: 5484: 5482: 5478: 5474: 5472: 5469: 5465: 5462: 5461: 5460: 5457: 5456: 5453: 5450: 5448: 5444: 5434: 5431: 5429: 5426: 5424: 5421: 5419: 5416: 5414: 5411: 5409: 5406: 5402: 5399: 5398: 5397: 5394: 5390: 5385: 5384: 5383: 5380: 5379: 5377: 5375: 5371: 5363: 5360: 5358: 5355: 5353: 5350: 5349: 5348: 5345: 5343: 5340: 5338: 5335: 5333: 5330: 5328: 5325: 5323: 5320: 5318: 5315: 5314: 5312: 5310: 5309:Propositional 5306: 5300: 5297: 5295: 5292: 5290: 5287: 5285: 5282: 5280: 5277: 5275: 5272: 5268: 5265: 5264: 5263: 5260: 5258: 5255: 5253: 5250: 5248: 5245: 5243: 5240: 5238: 5237:Logical truth 5235: 5233: 5230: 5229: 5227: 5225: 5221: 5218: 5216: 5212: 5206: 5203: 5201: 5198: 5196: 5193: 5191: 5188: 5186: 5183: 5181: 5177: 5173: 5169: 5167: 5164: 5162: 5159: 5157: 5153: 5150: 5149: 5147: 5145: 5139: 5134: 5128: 5125: 5123: 5120: 5118: 5115: 5113: 5110: 5108: 5105: 5103: 5100: 5098: 5095: 5093: 5090: 5088: 5085: 5083: 5080: 5078: 5075: 5073: 5070: 5066: 5063: 5062: 5061: 5058: 5057: 5055: 5051: 5047: 5040: 5035: 5033: 5028: 5026: 5021: 5020: 5017: 5005: 5004:Ernst Zermelo 5002: 5000: 4997: 4995: 4992: 4990: 4989:Willard Quine 4987: 4985: 4982: 4980: 4977: 4975: 4972: 4970: 4967: 4965: 4962: 4960: 4957: 4955: 4952: 4950: 4947: 4946: 4944: 4942: 4941:Set theorists 4938: 4932: 4929: 4927: 4924: 4922: 4919: 4918: 4916: 4910: 4908: 4905: 4904: 4901: 4893: 4890: 4888: 4887:Kripke–Platek 4885: 4881: 4878: 4877: 4876: 4873: 4872: 4871: 4868: 4864: 4861: 4860: 4859: 4858: 4854: 4850: 4847: 4846: 4845: 4842: 4841: 4838: 4835: 4833: 4830: 4828: 4825: 4823: 4820: 4819: 4817: 4813: 4807: 4804: 4802: 4799: 4797: 4794: 4792: 4790: 4785: 4783: 4780: 4778: 4775: 4772: 4768: 4765: 4763: 4760: 4756: 4753: 4751: 4748: 4746: 4743: 4742: 4741: 4738: 4735: 4731: 4728: 4726: 4723: 4721: 4718: 4716: 4713: 4712: 4710: 4707: 4703: 4697: 4694: 4692: 4689: 4687: 4684: 4682: 4679: 4677: 4674: 4672: 4669: 4667: 4664: 4660: 4657: 4655: 4652: 4651: 4650: 4647: 4645: 4642: 4640: 4637: 4635: 4632: 4630: 4627: 4624: 4620: 4617: 4615: 4612: 4610: 4607: 4606: 4604: 4598: 4595: 4594: 4591: 4585: 4582: 4580: 4577: 4575: 4572: 4570: 4567: 4565: 4562: 4560: 4557: 4555: 4552: 4549: 4546: 4544: 4541: 4540: 4538: 4536: 4532: 4524: 4523:specification 4521: 4519: 4516: 4515: 4514: 4511: 4510: 4507: 4504: 4502: 4499: 4497: 4494: 4492: 4489: 4487: 4484: 4482: 4479: 4477: 4474: 4472: 4469: 4465: 4462: 4461: 4460: 4457: 4455: 4452: 4448: 4445: 4443: 4440: 4438: 4435: 4434: 4433: 4430: 4428: 4425: 4424: 4422: 4420: 4416: 4411: 4401: 4398: 4397: 4395: 4391: 4387: 4380: 4375: 4373: 4368: 4366: 4361: 4360: 4357: 4348: 4347: 4342: 4339: 4335: 4330: 4329: 4328: 4327:at Wikiquote 4326: 4321: 4307: 4302: 4298: 4293: 4291: 4290:0-8218-1428-1 4287: 4283: 4279: 4276: 4272: 4268: 4264: 4259: 4255: 4250: 4246: 4240: 4236: 4232: 4228: 4227: 4219: 4215: 4212: 4210: 4206: 4201: 4200: 4190: 4186: 4182: 4178: 4174: 4170: 4165: 4164: 4156: 4149: 4141: 4138:(in German). 4137: 4130: 4122: 4118: 4114: 4110: 4106: 4102: 4097: 4092: 4088: 4084: 4083: 4075: 4064: 4060: 4056: 4052: 4048: 4044: 4040: 4033: 4026: 4018: 4014: 4010: 4006: 4002: 3998: 3991: 3983: 3979: 3976:(49): 42–56. 3975: 3971: 3967: 3960: 3952: 3948: 3944: 3940: 3935: 3930: 3926: 3922: 3915: 3907: 3903: 3899: 3895: 3890: 3885: 3881: 3877: 3873: 3867: 3856: 3849: 3842: 3831: 3827: 3820: 3816: 3810: 3802: 3798: 3794: 3790: 3786: 3782: 3775: 3760: 3756: 3749: 3730: 3723: 3716: 3708: 3704: 3699: 3694: 3690: 3686: 3679: 3671: 3667: 3663: 3659: 3655: 3651: 3647: 3643: 3639: 3632: 3624: 3620: 3616: 3612: 3608: 3604: 3600: 3596: 3589: 3587: 3578: 3572: 3568: 3567: 3562: 3556: 3549: 3544: 3537: 3535: 3529: 3525: 3521: 3517: 3513: 3509: 3505: 3501: 3494: 3483: 3479: 3472: 3468: 3462: 3451: 3447: 3443: 3436: 3429: 3427: 3415: 3411: 3407: 3400: 3393: 3391: 3382: 3378: 3374: 3370: 3365: 3364:10.1.1.37.295 3360: 3357:(2): 99–111. 3356: 3352: 3345: 3337: 3333: 3328: 3323: 3319: 3315: 3310: 3305: 3301: 3297: 3293: 3289: 3285: 3278: 3270: 3266: 3261: 3256: 3251: 3246: 3242: 3238: 3234: 3230: 3226: 3219: 3211: 3207: 3200: 3198: 3189: 3185: 3180: 3175: 3171: 3167: 3162: 3157: 3153: 3149: 3145: 3141: 3137: 3130: 3128: 3119: 3117:9780691024479 3113: 3109: 3104: 3103: 3094: 3086: 3082: 3076: 3074: 3072: 3063: 3057: 3049: 3045: 3041: 3037: 3036: 3031: 3027: 3026:Cantor, Georg 3021: 3017: 3007: 3004: 3002: 2999: 2997: 2994: 2992: 2989: 2987: 2984: 2982: 2979: 2978: 2956: 2953: 2950: 2942: 2935: 2926: 2922: 2915: 2907: 2902: 2893: 2889: 2882: 2865: 2856: 2849: 2842: 2832: 2824: 2817: 2807: 2795: 2792: 2774: 2766: 2756: 2745: 2742: 2737: 2729: 2722: 2712: 2700: 2699: 2698: 2679: 2668: 2665: 2662: 2657: 2644: 2640: 2616: 2606: 2598: 2591: 2582: 2578: 2573: 2570: 2567: 2555: 2538: 2535: 2532: 2524: 2517: 2508: 2504: 2497: 2489: 2484: 2475: 2471: 2464: 2447: 2438: 2431: 2424: 2414: 2411: 2408: 2400: 2393: 2383: 2371: 2370: 2369: 2367: 2363: 2338: 2327: 2324: 2321: 2316: 2303: 2299: 2281: 2278: 2275: 2267: 2260: 2250: 2238: 2235: 2231: 2210: 2199: 2196: 2193: 2188: 2175: 2171: 2153: 2145: 2138: 2128: 2116: 2113: 2109: 2091: 2088: 2085: 2077: 2070: 2060: 2048: 2047: 2046: 2044: 2040: 2020: 2010: 1991: 1975: 1971: 1967: 1962: 1958: 1951: 1948: 1945: 1923: 1919: 1915: 1910: 1906: 1899: 1896: 1893: 1884: 1882: 1878: 1862: 1840: 1837: 1833: 1829: 1824: 1820: 1799: 1777: 1773: 1769: 1764: 1760: 1751: 1747: 1729: 1726: 1723: 1715: 1708: 1699: 1676: 1663: 1659: 1655: 1651: 1635: 1632: 1627: 1618: 1613: 1610: 1606: 1600: 1597: 1592: 1583: 1574: 1556: 1553: 1548: 1539: 1530: 1526: 1522: 1518: 1513: 1511: 1495: 1492: 1489: 1469: 1447: 1443: 1439: 1434: 1421: 1413: 1397: 1390: 1370: 1361: 1357: 1352: 1349: 1346: 1334: 1333: 1332: 1316: 1312: 1308: 1305: 1302: 1299: 1279: 1259: 1251: 1232: 1214: 1210: 1191: 1174: 1170: 1166: 1156: 1153: 1148: 1144: 1140: 1138: 1119: 1113: 1110: 1087: 1079: 1075: 1071: 1067: 1065: 1047: 1018: 1009: 996: 992: 987: 985: 984:probabilities 981: 975: 973: 969: 965: 960: 958: 954: 950: 946: 941: 939: 935: 931: 921: 919: 915: 911: 906: 901: 899: 895: 889: 887: 883: 879: 875: 870: 856: 834: 831: 826: 822: 794: 765: 756: 735: 732: 725: 716: 707: 691: 683: 679: 675: 674: 668: 666: 662: 657: 655: 651: 647: 643: 639: 634: 632: 628: 624: 614: 598: 590: 583: 574: 551: 539:greater than 524: 511: 508:Assuming the 505: 487: 478: 474: 466: 458: 453: 445: 442: 439: 424: 406: 397: 393: 370: 366: 362: 358: 353: 351: 347: 343: 339: 334: 332: 328: 324: 320: 316: 311: 309: 305: 301: 297: 293: 289: 285: 281: 280: 275: 274: 267: 257: 255: 250: 246: 242: 238: 228: 226: 225: 224:the continuum 219: 217: 213: 208: 204: 200: 195: 179: 171: 166: 162: 153: 135: 127: 120: 111: 102: 101:aleph numbers 98: 94: 88: 84: 80: 78: 74: 70: 64: 63:. It states: 62: 61:infinite sets 58: 55:(abbreviated 54: 50: 46: 41: 37: 33: 19: 6754: 6552:Ultraproduct 6399:Model theory 6364:Independence 6300:Formal proof 6292:Proof theory 6275: 6248: 6205:real numbers 6177:second-order 6088:Substitution 5965:Metalanguage 5906:conservative 5879:Axiom schema 5823:Constructive 5793:Morse–Kelley 5775: 5759:Set theories 5738:Aleph number 5731:inaccessible 5637:Grothendieck 5521:intersection 5408:Higher-order 5396:Second-order 5342:Truth tables 5299:Venn diagram 5082:Formal proof 4954:Georg Cantor 4949:Paul Bernays 4880:Morse–Kelley 4855: 4788: 4787:Subset  4734:hereditarily 4696:Venn diagram 4654:ordered pair 4638: 4569:Intersection 4513:Axiom schema 4344: 4317: 4281: 4274: 4270: 4262: 4256:. Cambridge. 4253: 4234: 4202: 4172: 4168: 4154: 4148: 4139: 4135: 4129: 4096:math/0005179 4086: 4080: 4074: 4042: 4038: 4025: 4000: 3996: 3990: 3973: 3969: 3959: 3934:math/0211398 3924: 3920: 3914: 3879: 3875: 3866: 3841: 3825: 3809: 3784: 3780: 3774: 3762:. Retrieved 3758: 3748: 3736:. Retrieved 3715: 3688: 3684: 3678: 3645: 3641: 3631: 3598: 3594: 3564: 3555: 3543: 3533: 3531: 3503: 3499: 3493: 3477: 3461: 3445: 3441: 3409: 3405: 3354: 3350: 3344: 3291: 3287: 3277: 3232: 3228: 3218: 3205: 3143: 3139: 3101: 3093: 3084: 3056:cite journal 3039: 3033: 3020: 2642: 2638: 2636: 2365: 2361: 2359: 2301: 2297: 2229: 2173: 2169: 2111: 2107: 2042: 2038: 1997: 1885: 1880: 1876: 1652: 1529:aleph number 1514: 1420:beth numbers 1417: 1411: 1212: 1208: 1168: 1164: 1162: 1141: 1068: 988: 976: 961: 942: 927: 902: 890: 876:, point set 871: 671: 669: 665:Fields Medal 658: 635: 620: 507: 426: 365:equinumerous 360: 356: 354: 342:real numbers 335: 326: 312: 307: 303: 299: 295: 291: 287: 277: 271: 269: 234: 222: 220: 199:Georg Cantor 196: 152:beth numbers 90: 86: 82: 77:real numbers 66: 56: 52: 42: 40: 6662:Type theory 6610:undecidable 6542:Truth value 6429:equivalence 6108:non-logical 5721:Enumeration 5711:Isomorphism 5658:cardinality 5642:Von Neumann 5607:Ultrafilter 5572:Uncountable 5506:equivalence 5423:Quantifiers 5413:Fixed-point 5382:First-order 5262:Consistency 5247:Proposition 5224:Traditional 5195:Lindström's 5185:Compactness 5127:Type theory 5072:Cardinality 4979:Thomas Jech 4822:Alternative 4801:Uncountable 4755:Ultrafilter 4614:Cardinality 4518:replacement 4459:Determinacy 4269:Gödel, K.: 3764:30 December 3738:25 February 3081:Gödel, Kurt 2991:Cardinality 2986:Beth number 1145:proposes a 999:"(*)-axiom" 886:conjectures 646:inner model 327:cardinality 273:cardinality 207:independent 69:cardinality 45:mathematics 6978:Hypotheses 6947:Categories 6473:elementary 6166:arithmetic 6034:Quantifier 6012:functional 5884:Expression 5602:Transitive 5546:identities 5531:complement 5464:hereditary 5447:Set theory 4974:Kurt Gödel 4959:Paul Cohen 4796:Transitive 4564:Identities 4548:Complement 4535:Operations 4496:Regularity 4464:projective 4427:Adjunction 4386:Set theory 4205:PlanetMath 4142:: 127–142. 3548:Maddy 1988 3012:References 2234:cofinality 1855:for every 1654:Kurt Gödel 1517:Sierpiński 1387:for every 1292:such that 1147:multiverse 706:cofinality 650:consistent 631:Paul Cohen 627:Kurt Gödel 254:Paul Cohen 249:Kurt Gödel 216:Kurt Gödel 212:Paul Cohen 49:set theory 6744:Supertask 6647:Recursion 6605:decidable 6439:saturated 6417:of models 6340:deductive 6335:axiomatic 6255:Hilbert's 6242:Euclidean 6223:canonical 6146:axiomatic 6078:Signature 6007:Predicate 5896:Extension 5818:Ackermann 5743:Operation 5622:Universal 5612:Recursive 5587:Singleton 5582:Inhabited 5567:Countable 5557:Types of 5541:power set 5511:partition 5428:Predicate 5374:Predicate 5289:Syllogism 5279:Soundness 5252:Inference 5242:Tautology 5144:paradoxes 4907:Paradoxes 4827:Axiomatic 4806:Universal 4782:Singleton 4777:Recursive 4720:Countable 4715:Amorphous 4574:Power set 4491:Power set 4442:dependent 4437:countable 4346:MathWorld 4233:(2008) . 3889:1108.4223 3801:122205863 3698:1203.4026 3534:formalism 3359:CiteSeerX 2951:α 2947:ℵ 2936:α 2932:ℵ 2916:α 2912:ℵ 2908:⋅ 2903:α 2899:ℵ 2883:α 2879:ℵ 2866:α 2862:ℵ 2850:≤ 2843:α 2839:ℵ 2833:α 2829:ℵ 2825:≤ 2818:β 2814:ℵ 2808:α 2804:ℵ 2775:α 2771:ℵ 2757:α 2753:ℵ 2746:⁡ 2738:α 2734:ℵ 2730:≥ 2723:β 2719:ℵ 2713:α 2709:ℵ 2680:α 2676:ℵ 2669:⁡ 2663:≥ 2658:β 2654:ℵ 2617:β 2613:ℵ 2607:α 2603:ℵ 2599:≤ 2592:β 2588:ℵ 2568:β 2564:ℵ 2533:β 2529:ℵ 2518:β 2514:ℵ 2498:β 2494:ℵ 2490:⋅ 2485:β 2481:ℵ 2465:β 2461:ℵ 2448:β 2444:ℵ 2425:β 2421:ℵ 2409:β 2405:ℵ 2401:≤ 2394:β 2390:ℵ 2384:α 2380:ℵ 2339:α 2335:ℵ 2328:⁡ 2322:≥ 2317:β 2313:ℵ 2276:α 2272:ℵ 2261:β 2257:ℵ 2251:α 2247:ℵ 2211:α 2207:ℵ 2200:⁡ 2189:β 2185:ℵ 2154:α 2150:ℵ 2139:β 2135:ℵ 2129:α 2125:ℵ 2086:β 2082:ℵ 2071:β 2067:ℵ 2061:α 2057:ℵ 2021:β 2017:ℵ 2011:α 2007:ℵ 1955:→ 1916:≤ 1903:→ 1863:κ 1834:κ 1825:κ 1800:κ 1774:κ 1765:κ 1724:α 1720:ℵ 1709:α 1705:ℵ 1677:α 1673:ℵ 1624:ℵ 1614:⋅ 1589:ℵ 1545:ℵ 1490:α 1470:α 1448:α 1444:ℶ 1435:α 1431:ℵ 1398:α 1371:α 1367:ℵ 1347:α 1343:ℵ 1317:λ 1306:κ 1300:λ 1280:κ 1260:λ 1252:cardinal 1173:power set 1120:ϕ 1117:¬ 1114:∨ 1111:ϕ 1088:ϕ 1044:ℵ 1015:ℵ 938:formalist 934:platonist 857:ω 835:ω 823:ω 818:ℵ 795:ω 791:ℵ 762:ℵ 736:κ 722:ℵ 692:κ 595:ℵ 580:ℵ 548:ℵ 521:ℵ 484:ℵ 450:ℵ 446:: 440:∄ 403:ℵ 367:with the 284:bijection 218:in 1940. 176:ℵ 163:ℶ 132:ℵ 117:ℵ 95:with the 6973:Infinity 6729:Logicism 6722:timeline 6698:Concrete 6557:Validity 6527:T-schema 6520:Kripke's 6515:Tarski's 6510:semantic 6500:Strength 6449:submodel 6444:spectrum 6412:function 6260:Tarski's 6249:Elements 6236:geometry 6192:Robinson 6113:variable 6098:function 6071:spectrum 6061:Sentence 6017:variable 5960:Language 5913:Relation 5874:Automata 5864:Alphabet 5848:language 5702:-jection 5680:codomain 5666:Function 5627:Universe 5597:Infinite 5501:Relation 5284:Validity 5274:Argument 5172:theorem, 4911:Problems 4815:Theories 4791:Superset 4767:Infinite 4596:Concepts 4476:Infinity 4393:Overview 4214:Archived 4121:15577499 4063:Archived 3906:33807508 3855:Archived 3830:Archived 3817:(2011). 3729:Archived 3662:44152014 3623:38174418 3563:(1980). 3482:Archived 3469:(2011). 3450:Archived 3414:Archived 3336:16591132 3269:16577857 3188:16578557 3083:(1940). 3028:(1878). 2975:See also 2793:, while: 2641:+1 < 2553:, while: 2300:+1 < 2228:, where 2172:+1 < 1250:infinite 945:universe 878:topology 874:analysis 369:powerset 338:integers 323:infinite 315:integers 75:and the 73:integers 6671:Related 6468:Diagram 6366: ( 6345:Hilbert 6330:Systems 6325:Theorem 6203:of the 6148:systems 5928:Formula 5923:Grammar 5839: ( 5783:General 5496:Forcing 5481:Element 5401:Monadic 5176:paradox 5117:Theorem 5053:General 4849:General 4844:Zermelo 4750:subbase 4732: ( 4671:Forcing 4649:Element 4621: ( 4599:Methods 4486:Pairing 4197:Sources 4189:2274520 4113:2320282 4059:2695444 4017:2896574 3951:1510438 3670:1042552 3615:2273955 3528:0542765 3520:2320581 3381:2589047 3296:Bibcode 3260:1077160 3237:Bibcode 3148:Bibcode 2996:Ω-logic 2633: ; 2232:is the 1746:Foreman 1389:ordinal 995:Foreman 661:forcing 231:History 6434:finite 6197:Skolem 6150:  6125:Theory 6093:Symbol 6083:String 6066:atomic 5943:ground 5938:closed 5933:atomic 5889:ground 5852:syntax 5748:binary 5675:domain 5592:Finite 5357:finite 5215:Logics 5174:  5122:Theory 4740:Filter 4730:Finite 4666:Family 4609:Almost 4447:global 4432:Choice 4419:Axioms 4336:& 4288:  4241:  4187:  4119:  4111:  4057:  4015:  3949:  3904:  3799:  3668:  3660:  3621:  3613:  3573:  3526:  3518:  3379:  3361:  3334:  3327:300611 3324:  3316:  3267:  3257:  3186:  3179:221287 3176:  3168:  3114:  3110:–137. 1750:Woodin 964:Skolem 894:Woodin 644:L, an 51:, the 6424:Model 6172:Peano 6029:Proof 5869:Arity 5798:Naive 5685:image 5617:Fuzzy 5577:Empty 5526:union 5471:Class 5112:Model 5102:Lemma 5060:Axiom 4832:Naive 4762:Fuzzy 4725:Empty 4708:types 4659:tuple 4629:Class 4623:large 4584:Union 4501:Union 4185:JSTOR 4117:S2CID 4091:arXiv 4066:(PDF) 4055:JSTOR 4035:(PDF) 3947:S2CID 3929:arXiv 3902:S2CID 3884:arXiv 3858:(PDF) 3851:(PDF) 3833:(PDF) 3822:(PDF) 3797:S2CID 3732:(PDF) 3725:(PDF) 3693:arXiv 3691:(1). 3658:JSTOR 3619:S2CID 3611:JSTOR 3516:JSTOR 3485:(PDF) 3474:(PDF) 3453:(PDF) 3438:(PDF) 3417:(PDF) 3402:(PDF) 3377:JSTOR 3318:72252 3314:JSTOR 3170:71858 3166:JSTOR 2789:, by 2296:when 2168:when 2106:when 344:(see 6547:Type 6350:list 6154:list 6131:list 6120:Term 6054:rank 5948:open 5842:list 5654:Maps 5559:sets 5418:Free 5388:list 5138:list 5065:list 4745:base 4286:ISBN 4239:ISBN 3766:2021 3740:2006 3571:ISBN 3332:PMID 3265:PMID 3184:PMID 3112:ISBN 3062:link 3040:1878 2767:> 2645:and 2304:and 2194:< 2176:and 2041:and 1968:< 1949:< 1897:< 1770:> 1748:and 1418:The 1309:< 1303:< 1163:The 896:and 880:and 629:and 475:< 459:< 348:and 290:and 6234:of 6216:of 6164:of 5696:Sur 5670:Map 5477:Ur- 5459:Set 4706:Set 4177:doi 4101:doi 4047:doi 4043:109 4005:doi 3978:doi 3939:doi 3894:doi 3789:doi 3703:doi 3650:doi 3603:doi 3508:doi 3369:doi 3355:106 3322:PMC 3304:doi 3255:PMC 3245:doi 3174:PMC 3156:doi 3108:134 3044:doi 2114:+1; 1658:V=L 1215:or 1207:of 1035:is 809:or 782:is 317:or 276:or 91:In 43:In 6949:: 6931:24 6925:23 6920:22 6915:21 6910:20 6905:19 6900:18 6895:17 6890:16 6885:15 6880:14 6875:13 6870:12 6865:11 6860:10 6620:NP 6244:: 6238:: 6168:: 5845:), 5700:Bi 5692:In 4343:. 4183:. 4173:53 4171:. 4140:37 4115:. 4109:MR 4107:. 4099:. 4087:72 4085:. 4061:. 4053:. 4041:. 4037:. 4013:MR 4011:. 4001:17 3999:. 3968:. 3945:. 3937:. 3925:40 3900:. 3892:. 3878:. 3853:. 3824:. 3795:. 3785:69 3783:. 3757:. 3727:. 3701:. 3689:56 3687:. 3666:MR 3664:. 3656:. 3646:15 3644:. 3640:. 3617:. 3609:. 3599:51 3597:. 3585:^ 3530:. 3524:MR 3522:. 3514:. 3504:86 3502:. 3476:. 3446:48 3444:. 3440:. 3425:^ 3410:48 3408:. 3404:. 3389:^ 3375:. 3367:. 3353:. 3330:. 3320:. 3312:. 3302:. 3292:51 3290:. 3286:. 3263:. 3253:. 3243:. 3233:24 3231:. 3227:. 3208:. 3196:^ 3182:. 3172:. 3164:. 3154:. 3144:50 3142:. 3138:. 3126:^ 3070:^ 3058:}} 3054:{{ 3038:. 3032:. 2743:cf 2666:cf 2364:≤ 2325:cf 2230:cf 2197:cf 2110:≤ 2045:: 1414:). 869:. 633:. 613:. 504:. 333:. 256:. 194:. 154:: 103:: 79:." 57:CH 6933:) 6929:( 6855:9 6850:8 6845:7 6840:6 6835:5 6830:4 6825:3 6820:2 6815:1 6796:e 6789:t 6782:v 6700:/ 6615:P 6370:) 6156:) 6152:( 6049:∀ 6044:! 6039:∃ 6000:= 5995:↔ 5990:→ 5985:∧ 5980:∨ 5975:¬ 5698:/ 5694:/ 5668:/ 5479:) 5475:( 5362:∞ 5352:3 5140:) 5038:e 5031:t 5024:v 4789:· 4773:) 4769:( 4736:) 4625:) 4378:e 4371:t 4364:v 4349:. 4308:. 4299:. 4247:. 4211:. 4191:. 4179:: 4123:. 4103:: 4093:: 4049:: 4019:. 4007:: 3984:. 3980:: 3974:9 3953:. 3941:: 3931:: 3908:. 3896:: 3886:: 3880:5 3803:. 3791:: 3768:. 3742:. 3709:. 3705:: 3695:: 3672:. 3652:: 3625:. 3605:: 3579:. 3510:: 3383:. 3371:: 3338:. 3306:: 3298:: 3271:. 3247:: 3239:: 3212:. 3190:. 3158:: 3150:: 3120:. 3064:) 3046:: 2957:1 2954:+ 2943:= 2927:2 2923:= 2894:2 2890:= 2874:) 2857:2 2853:( 2762:) 2749:( 2685:) 2672:( 2643:α 2639:β 2583:2 2579:= 2574:1 2571:+ 2539:1 2536:+ 2525:= 2509:2 2505:= 2476:2 2472:= 2456:) 2439:2 2435:( 2432:= 2415:1 2412:+ 2366:β 2362:α 2356:. 2344:) 2331:( 2302:α 2298:β 2282:1 2279:+ 2268:= 2216:) 2203:( 2174:α 2170:β 2146:= 2112:β 2108:α 2092:1 2089:+ 2078:= 2043:β 2039:α 1976:B 1972:2 1963:A 1959:2 1952:B 1946:A 1924:B 1920:2 1911:A 1907:2 1900:B 1894:A 1881:n 1877:n 1841:+ 1838:+ 1830:= 1821:2 1778:+ 1761:2 1730:1 1727:+ 1716:= 1700:2 1636:n 1633:+ 1628:0 1619:2 1611:2 1607:= 1601:n 1598:+ 1593:0 1584:2 1557:n 1554:+ 1549:0 1540:2 1496:1 1493:= 1440:= 1362:2 1358:= 1353:1 1350:+ 1313:2 1236:) 1233:S 1230:( 1225:P 1213:S 1209:S 1195:) 1192:S 1189:( 1184:P 1169:S 1123:) 1108:( 1048:2 1019:0 1010:2 832:+ 827:1 766:0 757:2 733:= 726:0 717:2 599:1 591:= 584:0 575:2 552:0 525:1 488:0 479:2 471:| 467:S 463:| 454:0 443:S 407:0 398:2 394:= 390:| 385:R 380:| 361:S 357:S 308:T 304:S 300:T 296:S 292:T 288:S 180:1 172:= 167:1 136:1 128:= 121:0 112:2 38:. 20:)

Index

Generalized Continuum Hypothesis
Continuum assumption
The Continuum Hypothesis (album)
mathematics
set theory
infinite sets
cardinality
integers
real numbers
Zermelo–Fraenkel set theory
axiom of choice
aleph numbers
beth numbers
Georg Cantor
Hilbert's 23 problems
independent
Paul Cohen
Kurt Gödel
the continuum
list of important open questions
International Congress of Mathematicians
Axiomatic set theory
Kurt Gödel
Paul Cohen
Cardinal number
cardinality
cardinal number
bijection
integers
rational numbers

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