Knowledge (XXG)

Cardinality of the continuum

Source 📝

1111:, viewed as sets of positions where the expansion is one, almost give a one-to-one mapping from subsets of a countable set (the set of positions in the expansions) to real numbers, but it fails to be one-to-one for numbers with terminating binary expansions, which can also be represented by a non-terminating expansion that ends in a repeating sequence of 1s. This can be made into a one-to-one mapping by that adds one to the non-terminating repeating-1 expansions, mapping them into 2027: 1542: 1663: 1391: 3654: 1861: 1400: 2724: 3463: 1217: 388:, no matter how close they are to each other, there are always infinitely many other real numbers, and Cantor showed that they are as many as those contained in the whole set of real numbers. In other words, the 3346: 147: 1555: 357: 2091: 3303: 554: 2867: 2210: 3737: 1737: 3571: 1260: 2262: 841: 2517: 4512: 4159: 4080: 3699: 845:
In practice, this means that there are strictly more real numbers than there are integers. Cantor proved this statement in several different ways. For more information on this topic, see
4193: 3807: 3771: 2438: 2368: 1271: 712: 3566: 95: 2315: 2952: 3557: 1007: 951: 3493: 1694: 4120: 3927: 3893: 3387: 460: 4019: 3253: 3031: 2891: 2769: 2656: 2554: 2392: 1065: 1041: 768: 674: 920: 4947: 4464: 4442: 4420: 4392: 4370: 4342: 4320: 4291: 4265: 4237: 4215: 4045: 3984: 3957: 3858: 3836: 3414: 3228: 3204: 3093: 3061: 2466: 1824: 1794: 976: 424: 266: 244: 218: 196: 171: 58: 3179: 2979: 2918: 2796: 2632: 2585: 1851: 799: 649: 614: 583: 294: 2022:{\displaystyle {\mathfrak {c}}\leq \aleph _{0}\cdot 10^{\aleph _{0}}\leq 2^{\aleph _{0}}\cdot {(2^{4})}^{\aleph _{0}}=2^{\aleph _{0}+4\cdot \aleph _{0}}=2^{\aleph _{0}}} 1537:{\displaystyle {\mathfrak {c}}^{\aleph _{0}}={\aleph _{0}}^{\aleph _{0}}=n^{\aleph _{0}}={\mathfrak {c}}^{n}=\aleph _{0}{\mathfrak {c}}=n{\mathfrak {c}}={\mathfrak {c}}} 2131: 2163: 1141: 1109: 3522: 2822: 2605: 3129: 1796:. This makes it sensible to talk about, say, the first, the one-hundredth, or the millionth decimal place of π. Since the natural numbers have cardinality 1068: 1067:. This can be shown by providing one-to-one mappings in both directions between subsets of a countably infinite set and real numbers, and applying the 4527: 2662: 1071:
according to which two sets with one-to-one mappings in both directions have the same cardinality. In one direction, reals can be equated with
846: 366: 3421: 1148: 3311: 1658:{\displaystyle {\mathfrak {c}}^{\mathfrak {c}}=(2^{\aleph _{0}})^{\mathfrak {c}}=2^{{\mathfrak {c}}\times \aleph _{0}}=2^{\mathfrak {c}}} 108: 4397: 2825: 302: 4956: 4936: 4918: 4729: 4694: 2036: 3261: 2729: 719: 471: 2824:
being the continuum hypothesis). The same is true for most other alephs, although in some cases, equality can be ruled out by
2835: 2170: 4890: 4608: 3712: 1703: 850: 370: 1224: 4681:. Elements of Logic via Numbers and Sets. Springer Undergraduate Mathematics Series. Springer London. pp. 113–130. 2219: 4603: 369:
of 1874, part of his groundbreaking study of different infinities. The inequality was later stated more simply in his
806: 4598: 1386:{\displaystyle {\mathfrak {c}}^{2}=(2^{\aleph _{0}})^{2}=2^{2\times {\aleph _{0}}}=2^{\aleph _{0}}={\mathfrak {c}}.} 3649:{\displaystyle {\begin{aligned}f\colon \mathbb {R} ^{2}&\to \mathbb {C} \\(a,b)&\mapsto a+bi\end{aligned}}} 2477: 4475: 4129: 4050: 3669: 4989: 4167: 3781: 3745: 2982: 2403: 2320: 1771: 680: 3066: 74: 3183:
Furthermore, the real algebraic numbers and the real transcendental numbers are disjoint sets whose union is
2740:. That is, both the hypothesis and its negation are consistent with these axioms. In fact, for every nonzero 2280: 2165:
and consider that decimal fractions containing only 3 or 7 are only a part of the real numbers, then we get
2923: 3142: 3070: 61: 4881: 3528: 981: 925: 4973: 4885: 3470: 1670: 4096: 3903: 3869: 3363: 436: 377:: two sets have the same cardinality if, and only if, there exists a bijective function between them. 4825: 4758: 4297: 4000: 3234: 3012: 2872: 2750: 2637: 2535: 2527: 2373: 1046: 1012: 749: 743: 715: 655: 621: 872: 4994: 4347: 4268: 3813: 1263: 862: 463: 4447: 4425: 4403: 4375: 4353: 4325: 4303: 4274: 4248: 4220: 4198: 4028: 3967: 3940: 3841: 3819: 3397: 3211: 3187: 3076: 3044: 2449: 1799: 1777: 959: 407: 249: 227: 201: 179: 154: 41: 4644: 4090: 3863: 3157: 2986: 2957: 2896: 2774: 2610: 2563: 1829: 777: 627: 592: 561: 374: 272: 3150: 2098: 4999: 4952: 4932: 4914: 4913:. Princeton, NJ: D. Van Nostrand Company, 1960. Reprinted by Springer-Verlag, New York, 1974. 4861: 4843: 4794: 4776: 4725: 4690: 3136: 2998: 1748: 32: 2136: 4851: 4833: 4784: 4766: 4717: 4682: 4636: 4242: 3146: 2994: 1076: 4656: 1114: 1082: 4652: 3498: 3358: 1856:
Since each real number can be broken into an integer part and a decimal fraction, we get:
771: 742:
to compare the sizes of infinite sets. He famously showed that the set of real numbers is
431: 174: 68: 2801: 4829: 4762: 4546: 3664: 3392: 2990: 2741: 2590: 954: 4856: 4813: 4789: 4746: 3307:
A similar result follows for complex transcendental numbers, once we have proved that
3102: 4983: 4942: 3934: 3096: 2733: 1767: 1763:(This is true even in the case the expansion repeats, as in the first two examples.) 1079:. In the other direction, the binary expansions of numbers in the half-open interval 389: 4965: 4640: 2557: 1072: 735: 617: 586: 401: 362: 269: 65: 36: 865:, which states that the cardinality of any set is strictly less than that of its 4924: 4906: 4686: 4515: 3039: 2272: 739: 28: 4574: 4969: 4123: 3353: 2829: 2737: 20: 4847: 4780: 2719:{\displaystyle \nexists A\quad :\quad \aleph _{0}<|A|<{\mathfrak {c}}.} 624:, which asserts that there are no sets whose cardinality is strictly between 4086: 3960: 3705: 3660: 2469: 866: 221: 4865: 4798: 4771: 4711: 4838: 4721: 4161: â€“ the indicator function chooses elements of each subset to include) 3896: 4468:
the set of all automorphisms of the (discrete) field of complex numbers.
4648: 3458:{\displaystyle \left\vert \mathbb {R} ^{2}\right\vert ={\mathfrak {c}}} 2587:. In other words, the continuum hypothesis states that there is no set 98: 1212:{\displaystyle {\mathfrak {c}}=|\wp (\mathbb {N} )|=2^{\aleph _{0}}.} 3341:{\displaystyle \left\vert \mathbb {C} \right\vert ={\mathfrak {c}}} 3009:
A great many sets studied in mathematics have cardinality equal to
1395:
By using the rules of cardinal arithmetic, one can also show that
142:{\displaystyle {\mathbf {|}}{\mathbf {\mathbb {R} }}{\mathbf {|}}} 2728:
This statement is now known to be independent of the axioms of
861:
A variation of Cantor's diagonal argument can be used to prove
352:{\displaystyle {\mathfrak {c}}=2^{\aleph _{0}}>\aleph _{0}.} 4929:
Set Theory: The Third Millennium Edition, Revised and Expanded
714:. The truth or falsity of this hypothesis is undecidable and 4135: 4056: 3675: 2086:{\displaystyle \aleph _{0}+4\cdot \aleph _{0}=\aleph _{0}\,} 3298:{\displaystyle {\mathfrak {c}}-\aleph _{0}={\mathfrak {c}}} 426:, as well as with several other infinite sets, such as any 3417:
Per Cantor's proof of the cardinality of Euclidean space,
549:{\displaystyle |(a,b)|=|\mathbb {R} |=|\mathbb {R} ^{n}|.} 3153:.) So the cardinality of the real algebraic numbers is 3257:
the cardinality of the real transcendental numbers is
4478: 4450: 4428: 4406: 4378: 4356: 4328: 4306: 4277: 4251: 4223: 4201: 4170: 4132: 4099: 4053: 4031: 4003: 3970: 3943: 3906: 3872: 3844: 3822: 3784: 3748: 3715: 3672: 3569: 3531: 3501: 3473: 3424: 3400: 3366: 3314: 3264: 3237: 3214: 3190: 3160: 3105: 3079: 3047: 3015: 2960: 2926: 2899: 2875: 2862:{\displaystyle {\mathfrak {c}}\neq \aleph _{\omega }} 2838: 2804: 2777: 2753: 2665: 2640: 2613: 2593: 2566: 2538: 2480: 2452: 2406: 2376: 2323: 2283: 2222: 2205:{\displaystyle 2^{\aleph _{0}}\leq {\mathfrak {c}}\,} 2173: 2139: 2101: 2039: 1864: 1832: 1802: 1780: 1706: 1673: 1558: 1403: 1274: 1227: 1151: 1117: 1085: 1049: 1015: 984: 962: 928: 875: 809: 780: 752: 683: 658: 630: 595: 564: 474: 439: 410: 305: 275: 252: 230: 204: 182: 157: 111: 77: 44: 3732:{\displaystyle \mathbb {N} \rightarrow \mathbb {Z} } 1732:{\displaystyle 2^{\mathfrak {c}}>{\mathfrak {c}}} 2277:The sequence of beth numbers is defined by setting 1766:In any given case, the number of decimal places is 1255:{\displaystyle {\mathfrak {c}}^{2}={\mathfrak {c}}} 4948:Set Theory: An Introduction to Independence Proofs 4814:"The Independence of the Continuum Hypothesis, Ii" 4506: 4458: 4436: 4414: 4386: 4364: 4336: 4314: 4285: 4259: 4231: 4209: 4187: 4153: 4114: 4074: 4039: 4013: 3978: 3951: 3921: 3887: 3852: 3830: 3801: 3765: 3731: 3693: 3648: 3551: 3516: 3487: 3457: 3408: 3381: 3340: 3297: 3247: 3222: 3198: 3173: 3149:is countably infinite (assign to each formula its 3123: 3087: 3055: 3025: 2973: 2946: 2912: 2885: 2861: 2816: 2790: 2763: 2718: 2650: 2626: 2599: 2579: 2548: 2511: 2460: 2432: 2386: 2362: 2309: 2257:{\displaystyle {\mathfrak {c}}=2^{\aleph _{0}}\,.} 2256: 2204: 2157: 2125: 2085: 2021: 1845: 1818: 1788: 1731: 1688: 1657: 1536: 1385: 1254: 1211: 1135: 1103: 1059: 1035: 1001: 970: 945: 914: 835: 793: 762: 706: 668: 643: 608: 577: 548: 454: 418: 351: 288: 260: 238: 212: 190: 165: 141: 89: 52: 4627:Stillwell, John (2002). "The continuum problem". 133: 115: 4974:Creative Commons Attribution/Share-Alike License 770:is strictly greater than the cardinality of the 373:in 1891. Cantor defined cardinality in terms of 4818:Proceedings of the National Academy of Sciences 4751:Proceedings of the National Academy of Sciences 4713:Consistency of the Continuum Hypothesis. (AM-3) 3701:(the set of all subsets of the natural numbers) 836:{\displaystyle \aleph _{0}<{\mathfrak {c}}.} 4747:"The Independence of the Continuum Hypothesis" 2512:{\displaystyle 2^{\mathfrak {c}}=\beth _{2}.} 978:is uncountable). In fact, the cardinality of 8: 4507:{\displaystyle 2^{\mathfrak {c}}=\beth _{2}} 4154:{\displaystyle {\mathcal {P}}(\mathbb {R} )} 4075:{\displaystyle {\mathcal {P}}(\mathbb {R} )} 3694:{\displaystyle {\mathcal {P}}(\mathbb {N} )} 2732:with the axiom of choice (ZFC), as shown by 2152: 2140: 2120: 2108: 1747:Every real number has at least one infinite 4677:Johnson, D. L. (1998). "Cardinal Numbers". 4622: 4620: 4618: 4188:{\displaystyle \mathbb {R} ^{\mathbb {R} }} 3802:{\displaystyle \mathbb {R} ^{\mathbb {N} }} 3766:{\displaystyle \mathbb {Z} ^{\mathbb {N} }} 2433:{\displaystyle {\mathfrak {c}}=\beth _{1}.} 2363:{\displaystyle \beth _{k+1}=2^{\beth _{k}}} 707:{\displaystyle {\mathfrak {c}}=\aleph _{1}} 3033:. Some common examples are the following: 1075:, sets of rational numbers, or with their 4855: 4837: 4788: 4770: 4672: 4670: 4668: 4666: 4498: 4484: 4483: 4477: 4452: 4451: 4449: 4430: 4429: 4427: 4408: 4407: 4405: 4380: 4379: 4377: 4358: 4357: 4355: 4330: 4329: 4327: 4308: 4307: 4305: 4279: 4278: 4276: 4253: 4252: 4250: 4225: 4224: 4222: 4203: 4202: 4200: 4179: 4178: 4177: 4173: 4172: 4169: 4144: 4143: 4134: 4133: 4131: 4106: 4105: 4104: 4098: 4093:defined on subsets of the reals (the set 4065: 4064: 4055: 4054: 4052: 4033: 4032: 4030: 4005: 4004: 4002: 3972: 3971: 3969: 3945: 3944: 3942: 3913: 3909: 3908: 3905: 3879: 3875: 3874: 3871: 3846: 3845: 3843: 3824: 3823: 3821: 3793: 3792: 3791: 3787: 3786: 3783: 3757: 3756: 3755: 3751: 3750: 3747: 3725: 3724: 3717: 3716: 3714: 3684: 3683: 3674: 3673: 3671: 3600: 3599: 3586: 3582: 3581: 3570: 3568: 3545: 3544: 3530: 3500: 3481: 3480: 3472: 3449: 3448: 3435: 3431: 3430: 3423: 3402: 3401: 3399: 3373: 3369: 3368: 3365: 3332: 3331: 3320: 3319: 3313: 3289: 3288: 3279: 3266: 3265: 3263: 3239: 3238: 3236: 3216: 3215: 3213: 3192: 3191: 3189: 3165: 3159: 3104: 3081: 3080: 3078: 3049: 3048: 3046: 3017: 3016: 3014: 2965: 2959: 2936: 2931: 2925: 2904: 2898: 2877: 2876: 2874: 2853: 2840: 2839: 2837: 2803: 2782: 2776: 2755: 2754: 2752: 2707: 2706: 2698: 2690: 2681: 2664: 2642: 2641: 2639: 2618: 2612: 2592: 2571: 2565: 2540: 2539: 2537: 2500: 2486: 2485: 2479: 2454: 2453: 2451: 2446:, is the cardinality of the power set of 2421: 2408: 2407: 2405: 2378: 2377: 2375: 2352: 2347: 2328: 2322: 2301: 2288: 2282: 2250: 2242: 2237: 2224: 2223: 2221: 2201: 2195: 2194: 2183: 2178: 2172: 2138: 2100: 2082: 2076: 2063: 2044: 2038: 2011: 2006: 1991: 1972: 1967: 1952: 1947: 1937: 1929: 1917: 1912: 1897: 1892: 1879: 1866: 1865: 1863: 1837: 1831: 1807: 1801: 1782: 1781: 1779: 1743:Alternative explanation for 𝔠 = 2 1723: 1722: 1712: 1711: 1705: 1679: 1678: 1672: 1648: 1647: 1632: 1619: 1618: 1617: 1603: 1602: 1590: 1585: 1568: 1567: 1561: 1560: 1557: 1528: 1527: 1518: 1517: 1505: 1504: 1498: 1485: 1479: 1478: 1466: 1461: 1446: 1441: 1434: 1429: 1417: 1412: 1406: 1405: 1402: 1374: 1373: 1362: 1357: 1341: 1336: 1329: 1316: 1304: 1299: 1283: 1277: 1276: 1273: 1246: 1245: 1236: 1230: 1229: 1226: 1198: 1193: 1181: 1174: 1173: 1162: 1153: 1152: 1150: 1116: 1084: 1051: 1050: 1048: 1025: 1020: 1014: 992: 991: 983: 964: 963: 961: 936: 935: 927: 905: 897: 896: 884: 876: 874: 824: 823: 814: 808: 785: 779: 754: 753: 751: 698: 685: 684: 682: 660: 659: 657: 635: 629: 600: 594: 569: 563: 558:The smallest infinite cardinal number is 538: 532: 528: 527: 521: 513: 509: 508: 503: 495: 475: 473: 446: 442: 441: 438: 412: 411: 409: 340: 325: 320: 307: 306: 304: 280: 274: 254: 253: 251: 232: 231: 229: 206: 205: 203: 184: 183: 181: 159: 158: 156: 132: 131: 130: 124: 123: 122: 121: 114: 113: 112: 110: 90:{\displaystyle {\mathbf {\mathfrak {c}}}} 80: 79: 78: 76: 46: 45: 43: 4964:This article incorporates material from 4877: 4875: 4528:Cardinal characteristic of the continuum 2607:whose cardinality lies strictly between 4538: 1696:is the cardinality of the power set of 220:has the same number of elements as the 3777:the set of sequences of real numbers, 3005:Sets with cardinality of the continuum 2532:The continuum hypothesis asserts that 2310:{\displaystyle \beth _{0}=\aleph _{0}} 297:, the cardinality of the continuum is 246:. Symbolically, if the cardinality of 16:Cardinality of the set of real numbers 2947:{\displaystyle \aleph _{\omega _{1}}} 7: 4568: 4566: 2468:(i.e. the set of all subsets of the 4485: 4006: 3997:Sets with cardinality greater than 3552:{\displaystyle a,b\in \mathbb {R} } 3450: 3333: 3290: 3267: 3240: 3018: 2878: 2841: 2756: 2708: 2643: 2541: 2487: 2409: 2379: 2225: 2196: 1867: 1724: 1713: 1680: 1649: 1620: 1604: 1569: 1562: 1529: 1519: 1506: 1480: 1407: 1375: 1278: 1247: 1231: 1154: 1052: 847:Cantor's first uncountability proof 825: 755: 686: 661: 308: 81: 4547:"Transfinite number | mathematics" 3561:We therefore define the bijection 3276: 3162: 2928: 2901: 2850: 2779: 2678: 2615: 2568: 2298: 2239: 2180: 2073: 2060: 2041: 2008: 1988: 1969: 1949: 1914: 1894: 1876: 1834: 1804: 1629: 1587: 1495: 1463: 1443: 1431: 1414: 1359: 1338: 1301: 1195: 1167: 1069:Cantor–Bernstein–Schroeder theorem 1022: 1002:{\displaystyle \wp (\mathbb {N} )} 985: 946:{\displaystyle \wp (\mathbb {N} )} 929: 811: 782: 695: 632: 597: 566: 337: 322: 277: 14: 3488:{\displaystyle c\in \mathbb {C} } 1689:{\displaystyle 2^{\mathfrak {c}}} 4745:Cohen, Paul J. (December 1963). 4115:{\displaystyle 2^{\mathbb {R} }} 3922:{\displaystyle \mathbb {R} ^{n}} 3888:{\displaystyle \mathbb {R} ^{n}} 3708:of integers (i.e. all functions 3382:{\displaystyle \mathbb {R} ^{n}} 1774:with the set of natural numbers 455:{\displaystyle \mathbb {R} ^{n}} 4812:Cohen, Paul J. (January 1964). 4014:{\displaystyle {\mathfrak {c}}} 3248:{\displaystyle {\mathfrak {c}}} 3208:Thus, since the cardinality of 3026:{\displaystyle {\mathfrak {c}}} 2886:{\displaystyle {\mathfrak {c}}} 2764:{\displaystyle {\mathfrak {c}}} 2676: 2672: 2651:{\displaystyle {\mathfrak {c}}} 2549:{\displaystyle {\mathfrak {c}}} 2387:{\displaystyle {\mathfrak {c}}} 1550:is any finite cardinal ≄ 2 and 1060:{\displaystyle {\mathfrak {c}}} 1036:{\displaystyle 2^{\aleph _{0}}} 763:{\displaystyle {\mathfrak {c}}} 669:{\displaystyle {\mathfrak {c}}} 4972:, which is licensed under the 4641:10.1080/00029890.2002.11919865 4148: 4140: 4069: 4061: 3721: 3688: 3680: 3627: 3620: 3608: 3596: 3118: 3106: 2699: 2691: 1943: 1930: 1599: 1578: 1313: 1292: 1182: 1178: 1170: 1163: 1130: 1118: 1098: 1086: 996: 988: 940: 932: 915:{\displaystyle |A|<2^{|A|}} 906: 898: 885: 877: 539: 522: 514: 504: 496: 492: 480: 476: 1: 4891:American Mathematical Monthly 4629:American Mathematical Monthly 3993:Sets with greater cardinality 3495:can be uniquely expressed as 2095:On the other hand, if we map 1770:since they can be put into a 380:Between any two real numbers 4966:cardinality of the continuum 4459:{\displaystyle \mathbb {R} } 4437:{\displaystyle \mathbb {Q} } 4415:{\displaystyle \mathbb {N} } 4398:Stone–Čech compactifications 4387:{\displaystyle \mathbb {R} } 4365:{\displaystyle \mathbb {R} } 4337:{\displaystyle \mathbb {R} } 4315:{\displaystyle \mathbb {R} } 4286:{\displaystyle \mathbb {R} } 4260:{\displaystyle \mathbb {R} } 4232:{\displaystyle \mathbb {R} } 4210:{\displaystyle \mathbb {R} } 4040:{\displaystyle \mathbb {R} } 3979:{\displaystyle \mathbb {R} } 3952:{\displaystyle \mathbb {R} } 3853:{\displaystyle \mathbb {R} } 3831:{\displaystyle \mathbb {R} } 3409:{\displaystyle \mathbb {C} } 3223:{\displaystyle \mathbb {R} } 3199:{\displaystyle \mathbb {R} } 3088:{\displaystyle \mathbb {R} } 3056:{\displaystyle \mathbb {R} } 2798:is independent of ZFC (case 2461:{\displaystyle \mathbb {R} } 2031:where we used the fact that 1819:{\displaystyle \aleph _{0},} 1789:{\displaystyle \mathbb {N} } 971:{\displaystyle \mathbb {N} } 722:with axiom of choice (ZFC). 419:{\displaystyle \mathbb {R} } 261:{\displaystyle \mathbb {N} } 239:{\displaystyle \mathbb {N} } 213:{\displaystyle \mathbb {R} } 191:{\displaystyle \mathbb {N} } 166:{\displaystyle \mathbb {R} } 53:{\displaystyle \mathbb {R} } 25:cardinality of the continuum 4687:10.1007/978-1-4471-0603-6_6 4679:Chapter 6: Cardinal numbers 4604:Encyclopedia of Mathematics 4472:These all have cardinality 3174:{\displaystyle \aleph _{0}} 2974:{\displaystyle \omega _{1}} 2913:{\displaystyle \aleph _{1}} 2791:{\displaystyle \aleph _{n}} 2730:Zermelo–Fraenkel set theory 2627:{\displaystyle \aleph _{0}} 2580:{\displaystyle \aleph _{1}} 2394:is the second beth number, 1846:{\displaystyle \aleph _{0}} 922:(and so that the power set 794:{\displaystyle \aleph _{0}} 720:Zermelo–Fraenkel set theory 644:{\displaystyle \aleph _{0}} 609:{\displaystyle \aleph _{1}} 578:{\displaystyle \aleph _{0}} 289:{\displaystyle \aleph _{0}} 173:are more numerous than the 5016: 4921:(Springer-Verlag edition). 4710:Gödel, Kurt (1940-12-31). 4025:the set of all subsets of 2985:, so it could be either a 2525: 2270: 1262:can be demonstrated using 851:Cantor's diagonal argument 738:introduced the concept of 589:). The second smallest is 2983:first uncountable ordinal 2126:{\displaystyle 2=\{0,1\}} 1853:digits in its expansion. 1772:one-to-one correspondence 1143:. Thus, we conclude that 2522:The continuum hypothesis 4551:Encyclopedia Britannica 4267:, i.e., the set of all 2442:The third beth number, 2158:{\displaystyle \{3,7\}} 718:within the widely used 60:, sometimes called the 4772:10.1073/pnas.50.6.1143 4508: 4460: 4438: 4416: 4388: 4366: 4338: 4316: 4287: 4261: 4233: 4211: 4195:of all functions from 4189: 4155: 4116: 4076: 4041: 4015: 3980: 3953: 3923: 3889: 3854: 3832: 3803: 3767: 3733: 3695: 3650: 3553: 3518: 3489: 3459: 3410: 3383: 3342: 3299: 3249: 3224: 3200: 3175: 3143:transcendental numbers 3125: 3089: 3057: 3027: 2975: 2948: 2914: 2887: 2863: 2818: 2792: 2765: 2720: 2652: 2628: 2601: 2581: 2550: 2513: 2462: 2434: 2388: 2364: 2311: 2258: 2206: 2159: 2127: 2087: 2023: 1847: 1820: 1790: 1733: 1690: 1659: 1538: 1387: 1256: 1221:The cardinal equality 1213: 1137: 1105: 1061: 1037: 1003: 972: 947: 916: 837: 795: 764: 708: 670: 645: 610: 579: 550: 456: 420: 353: 290: 262: 240: 214: 192: 167: 143: 91: 54: 4882:Was Cantor Surprised? 4839:10.1073/pnas.51.1.105 4722:10.1515/9781400881635 4579:mathworld.wolfram.com 4509: 4461: 4439: 4417: 4389: 4367: 4339: 4317: 4288: 4262: 4234: 4212: 4190: 4156: 4117: 4077: 4042: 4016: 3981: 3959:(i.e. the set of all 3954: 3924: 3895:(i.e. the set of all 3890: 3855: 3833: 3804: 3768: 3734: 3696: 3651: 3554: 3519: 3490: 3460: 3411: 3384: 3343: 3300: 3250: 3225: 3201: 3176: 3126: 3090: 3058: 3028: 2976: 2949: 2915: 2888: 2864: 2819: 2793: 2766: 2721: 2653: 2629: 2602: 2582: 2551: 2514: 2463: 2435: 2389: 2365: 2312: 2259: 2207: 2160: 2128: 2088: 2024: 1848: 1826:each real number has 1821: 1791: 1734: 1691: 1660: 1539: 1388: 1257: 1214: 1138: 1136:{\displaystyle [1,2)} 1106: 1104:{\displaystyle [0,1)} 1062: 1038: 1004: 973: 948: 917: 838: 796: 765: 709: 671: 646: 611: 580: 551: 457: 421: 354: 291: 263: 241: 215: 193: 168: 144: 92: 55: 4476: 4448: 4426: 4404: 4376: 4354: 4326: 4304: 4275: 4249: 4221: 4199: 4168: 4130: 4097: 4051: 4029: 4001: 3968: 3941: 3904: 3870: 3842: 3820: 3782: 3746: 3713: 3670: 3567: 3529: 3517:{\displaystyle a+bi} 3499: 3471: 3422: 3398: 3364: 3312: 3262: 3235: 3212: 3188: 3158: 3103: 3077: 3045: 3013: 2958: 2924: 2897: 2873: 2836: 2802: 2775: 2751: 2663: 2638: 2611: 2591: 2564: 2536: 2528:Continuum hypothesis 2478: 2450: 2404: 2374: 2321: 2281: 2220: 2171: 2137: 2099: 2037: 1862: 1830: 1800: 1778: 1704: 1671: 1556: 1401: 1272: 1225: 1149: 1115: 1083: 1047: 1013: 982: 960: 926: 873: 807: 778: 750: 744:uncountably infinite 681: 656: 628: 622:continuum hypothesis 593: 562: 472: 437: 408: 367:uncountability proof 303: 273: 250: 228: 202: 180: 155: 109: 75: 42: 4830:1964PNAS...51..105C 4763:1963PNAS...50.1143C 4573:Weisstein, Eric W. 4348:Lebesgue-measurable 4298:Lebesgue-integrable 4269:Lebesgue measurable 4091:indicator functions 3467:By definition, any 2817:{\displaystyle n=1} 2556:is also the second 1264:cardinal arithmetic 857:Cardinal equalities 464:space filling curve 375:bijective functions 361:This was proven by 4886:Fernando Q. GouvĂȘa 4504: 4456: 4434: 4412: 4384: 4362: 4334: 4312: 4283: 4257: 4243:Lebesgue σ-algebra 4229: 4207: 4185: 4151: 4112: 4072: 4037: 4011: 3976: 3949: 3919: 3885: 3864:Euclidean topology 3850: 3828: 3799: 3763: 3729: 3691: 3646: 3644: 3549: 3514: 3485: 3455: 3406: 3379: 3338: 3295: 3245: 3220: 3196: 3171: 3137:irrational numbers 3121: 3085: 3053: 3023: 2987:successor cardinal 2971: 2944: 2910: 2883: 2869:). In particular, 2859: 2828:on the grounds of 2814: 2788: 2761: 2716: 2648: 2624: 2597: 2577: 2546: 2509: 2458: 2430: 2384: 2360: 2307: 2254: 2202: 2155: 2123: 2083: 2019: 1843: 1816: 1786: 1729: 1686: 1655: 1534: 1383: 1252: 1209: 1133: 1101: 1057: 1033: 999: 968: 943: 912: 833: 791: 760: 704: 666: 641: 606: 575: 546: 452: 416: 349: 286: 258: 236: 210: 188: 163: 139: 87: 71:and is denoted by 50: 4047:(i.e., power set 3147:algebraic numbers 3069:) closed or open 2999:singular cardinal 2600:{\displaystyle A} 1749:decimal expansion 1077:binary expansions 371:diagonal argument 151:The real numbers 31:or "size" of the 5007: 4990:Cardinal numbers 4911:Naive set theory 4895: 4879: 4870: 4869: 4859: 4841: 4809: 4803: 4802: 4792: 4774: 4757:(6): 1143–1148. 4742: 4736: 4735: 4707: 4701: 4700: 4674: 4661: 4660: 4624: 4613: 4612: 4599:"Cantor theorem" 4595: 4589: 4588: 4586: 4585: 4570: 4561: 4560: 4558: 4557: 4543: 4513: 4511: 4510: 4505: 4503: 4502: 4490: 4489: 4488: 4465: 4463: 4462: 4457: 4455: 4443: 4441: 4440: 4435: 4433: 4421: 4419: 4418: 4413: 4411: 4393: 4391: 4390: 4385: 4383: 4371: 4369: 4368: 4363: 4361: 4343: 4341: 4340: 4335: 4333: 4321: 4319: 4318: 4313: 4311: 4292: 4290: 4289: 4284: 4282: 4266: 4264: 4263: 4258: 4256: 4238: 4236: 4235: 4230: 4228: 4216: 4214: 4213: 4208: 4206: 4194: 4192: 4191: 4186: 4184: 4183: 4182: 4176: 4160: 4158: 4157: 4152: 4147: 4139: 4138: 4121: 4119: 4118: 4113: 4111: 4110: 4109: 4081: 4079: 4078: 4073: 4068: 4060: 4059: 4046: 4044: 4043: 4038: 4036: 4020: 4018: 4017: 4012: 4010: 4009: 3987: 3985: 3983: 3982: 3977: 3975: 3958: 3956: 3955: 3950: 3948: 3930: 3928: 3926: 3925: 3920: 3918: 3917: 3912: 3894: 3892: 3891: 3886: 3884: 3883: 3878: 3859: 3857: 3856: 3851: 3849: 3837: 3835: 3834: 3829: 3827: 3809: 3808: 3806: 3805: 3800: 3798: 3797: 3796: 3790: 3774: 3772: 3770: 3769: 3764: 3762: 3761: 3760: 3754: 3740: 3738: 3736: 3735: 3730: 3728: 3720: 3700: 3698: 3697: 3692: 3687: 3679: 3678: 3655: 3653: 3652: 3647: 3645: 3603: 3591: 3590: 3585: 3560: 3558: 3556: 3555: 3550: 3548: 3523: 3521: 3520: 3515: 3494: 3492: 3491: 3486: 3484: 3466: 3464: 3462: 3461: 3456: 3454: 3453: 3444: 3440: 3439: 3434: 3415: 3413: 3412: 3407: 3405: 3388: 3386: 3385: 3380: 3378: 3377: 3372: 3349: 3347: 3345: 3344: 3339: 3337: 3336: 3327: 3323: 3306: 3304: 3302: 3301: 3296: 3294: 3293: 3284: 3283: 3271: 3270: 3256: 3254: 3252: 3251: 3246: 3244: 3243: 3229: 3227: 3226: 3221: 3219: 3207: 3205: 3203: 3202: 3197: 3195: 3182: 3180: 3178: 3177: 3172: 3170: 3169: 3145:The set of real 3132: 3130: 3128: 3127: 3124:{\displaystyle } 3122: 3094: 3092: 3091: 3086: 3084: 3062: 3060: 3059: 3054: 3052: 3032: 3030: 3029: 3024: 3022: 3021: 2995:regular cardinal 2980: 2978: 2977: 2972: 2970: 2969: 2953: 2951: 2950: 2945: 2943: 2942: 2941: 2940: 2919: 2917: 2916: 2911: 2909: 2908: 2893:could be either 2892: 2890: 2889: 2884: 2882: 2881: 2868: 2866: 2865: 2860: 2858: 2857: 2845: 2844: 2823: 2821: 2820: 2815: 2797: 2795: 2794: 2789: 2787: 2786: 2770: 2768: 2767: 2762: 2760: 2759: 2725: 2723: 2722: 2717: 2712: 2711: 2702: 2694: 2686: 2685: 2657: 2655: 2654: 2649: 2647: 2646: 2633: 2631: 2630: 2625: 2623: 2622: 2606: 2604: 2603: 2598: 2586: 2584: 2583: 2578: 2576: 2575: 2555: 2553: 2552: 2547: 2545: 2544: 2518: 2516: 2515: 2510: 2505: 2504: 2492: 2491: 2490: 2467: 2465: 2464: 2459: 2457: 2439: 2437: 2436: 2431: 2426: 2425: 2413: 2412: 2393: 2391: 2390: 2385: 2383: 2382: 2369: 2367: 2366: 2361: 2359: 2358: 2357: 2356: 2339: 2338: 2316: 2314: 2313: 2308: 2306: 2305: 2293: 2292: 2263: 2261: 2260: 2255: 2249: 2248: 2247: 2246: 2229: 2228: 2211: 2209: 2208: 2203: 2200: 2199: 2190: 2189: 2188: 2187: 2164: 2162: 2161: 2156: 2132: 2130: 2129: 2124: 2092: 2090: 2089: 2084: 2081: 2080: 2068: 2067: 2049: 2048: 2028: 2026: 2025: 2020: 2018: 2017: 2016: 2015: 1998: 1997: 1996: 1995: 1977: 1976: 1959: 1958: 1957: 1956: 1946: 1942: 1941: 1924: 1923: 1922: 1921: 1904: 1903: 1902: 1901: 1884: 1883: 1871: 1870: 1852: 1850: 1849: 1844: 1842: 1841: 1825: 1823: 1822: 1817: 1812: 1811: 1795: 1793: 1792: 1787: 1785: 1757:1/3 = 0.33333... 1754:1/2 = 0.50000... 1738: 1736: 1735: 1730: 1728: 1727: 1718: 1717: 1716: 1695: 1693: 1692: 1687: 1685: 1684: 1683: 1664: 1662: 1661: 1656: 1654: 1653: 1652: 1639: 1638: 1637: 1636: 1624: 1623: 1609: 1608: 1607: 1597: 1596: 1595: 1594: 1574: 1573: 1572: 1566: 1565: 1543: 1541: 1540: 1535: 1533: 1532: 1523: 1522: 1510: 1509: 1503: 1502: 1490: 1489: 1484: 1483: 1473: 1472: 1471: 1470: 1453: 1452: 1451: 1450: 1440: 1439: 1438: 1424: 1423: 1422: 1421: 1411: 1410: 1392: 1390: 1389: 1384: 1379: 1378: 1369: 1368: 1367: 1366: 1349: 1348: 1347: 1346: 1345: 1321: 1320: 1311: 1310: 1309: 1308: 1288: 1287: 1282: 1281: 1261: 1259: 1258: 1253: 1251: 1250: 1241: 1240: 1235: 1234: 1218: 1216: 1215: 1210: 1205: 1204: 1203: 1202: 1185: 1177: 1166: 1158: 1157: 1142: 1140: 1139: 1134: 1110: 1108: 1107: 1102: 1066: 1064: 1063: 1058: 1056: 1055: 1042: 1040: 1039: 1034: 1032: 1031: 1030: 1029: 1009:, by definition 1008: 1006: 1005: 1000: 995: 977: 975: 974: 969: 967: 952: 950: 949: 944: 939: 921: 919: 918: 913: 911: 910: 909: 901: 888: 880: 863:Cantor's theorem 842: 840: 839: 834: 829: 828: 819: 818: 800: 798: 797: 792: 790: 789: 769: 767: 766: 761: 759: 758: 716:cannot be proven 713: 711: 710: 705: 703: 702: 690: 689: 676: 675: 673: 672: 667: 665: 664: 650: 648: 647: 642: 640: 639: 615: 613: 612: 607: 605: 604: 584: 582: 581: 576: 574: 573: 555: 553: 552: 547: 542: 537: 536: 531: 525: 517: 512: 507: 499: 479: 461: 459: 458: 453: 451: 450: 445: 425: 423: 422: 417: 415: 384: <  358: 356: 355: 350: 345: 344: 332: 331: 330: 329: 312: 311: 295: 293: 292: 287: 285: 284: 267: 265: 264: 259: 257: 245: 243: 242: 237: 235: 219: 217: 216: 211: 209: 197: 195: 194: 189: 187: 172: 170: 169: 164: 162: 148: 146: 145: 140: 138: 137: 136: 129: 128: 127: 120: 119: 118: 96: 94: 93: 88: 86: 85: 84: 59: 57: 56: 51: 49: 5015: 5014: 5010: 5009: 5008: 5006: 5005: 5004: 4980: 4979: 4903: 4898: 4880: 4873: 4811: 4810: 4806: 4744: 4743: 4739: 4732: 4709: 4708: 4704: 4697: 4676: 4675: 4664: 4626: 4625: 4616: 4597: 4596: 4592: 4583: 4581: 4572: 4571: 4564: 4555: 4553: 4545: 4544: 4540: 4536: 4524: 4494: 4479: 4474: 4473: 4446: 4445: 4424: 4423: 4402: 4401: 4374: 4373: 4352: 4351: 4350:functions from 4346:the set of all 4324: 4323: 4302: 4301: 4300:functions from 4296:the set of all 4273: 4272: 4247: 4246: 4219: 4218: 4197: 4196: 4171: 4166: 4165: 4128: 4127: 4100: 4095: 4094: 4049: 4048: 4027: 4026: 3999: 3998: 3995: 3990: 3966: 3965: 3964: 3939: 3938: 3935:Borel σ-algebra 3907: 3902: 3901: 3900: 3873: 3868: 3867: 3840: 3839: 3818: 3817: 3816:functions from 3812:the set of all 3785: 3780: 3779: 3778: 3749: 3744: 3743: 3742: 3711: 3710: 3709: 3668: 3667: 3665:natural numbers 3656: 3643: 3642: 3623: 3605: 3604: 3592: 3580: 3565: 3564: 3527: 3526: 3525: 3497: 3496: 3469: 3468: 3429: 3425: 3420: 3419: 3418: 3396: 3395: 3393:complex numbers 3367: 3362: 3361: 3359:Euclidean space 3315: 3310: 3309: 3308: 3275: 3260: 3259: 3258: 3233: 3232: 3231: 3210: 3209: 3186: 3185: 3184: 3161: 3156: 3155: 3154: 3101: 3100: 3099: 3075: 3074: 3043: 3042: 3011: 3010: 3007: 2993:, and either a 2961: 2956: 2955: 2932: 2927: 2922: 2921: 2900: 2895: 2894: 2871: 2870: 2849: 2834: 2833: 2826:König's theorem 2800: 2799: 2778: 2773: 2772: 2749: 2748: 2747:, the equality 2726: 2677: 2661: 2660: 2636: 2635: 2614: 2609: 2608: 2589: 2588: 2567: 2562: 2561: 2534: 2533: 2530: 2524: 2519: 2496: 2481: 2476: 2475: 2448: 2447: 2440: 2417: 2402: 2401: 2372: 2371: 2348: 2343: 2324: 2319: 2318: 2297: 2284: 2279: 2278: 2275: 2269: 2264: 2238: 2233: 2218: 2217: 2212: 2179: 2174: 2169: 2168: 2135: 2134: 2097: 2096: 2093: 2072: 2059: 2040: 2035: 2034: 2029: 2007: 2002: 1987: 1968: 1963: 1948: 1933: 1928: 1913: 1908: 1893: 1888: 1875: 1860: 1859: 1833: 1828: 1827: 1803: 1798: 1797: 1776: 1775: 1761: 1760:π = 3.14159.... 1758: 1755: 1751:. For example, 1745: 1707: 1702: 1701: 1674: 1669: 1668: 1665: 1643: 1628: 1613: 1598: 1586: 1581: 1559: 1554: 1553: 1544: 1494: 1477: 1462: 1457: 1442: 1430: 1428: 1413: 1404: 1399: 1398: 1393: 1358: 1353: 1337: 1325: 1312: 1300: 1295: 1275: 1270: 1269: 1228: 1223: 1222: 1219: 1194: 1189: 1147: 1146: 1113: 1112: 1081: 1080: 1045: 1044: 1021: 1016: 1011: 1010: 980: 979: 958: 957: 955:natural numbers 924: 923: 892: 871: 870: 859: 843: 810: 805: 804: 781: 776: 775: 772:natural numbers 748: 747: 733: 728: 694: 679: 678: 654: 653: 652: 631: 626: 625: 596: 591: 590: 565: 560: 559: 556: 526: 470: 469: 440: 435: 434: 432:Euclidean space 406: 405: 359: 336: 321: 316: 301: 300: 276: 271: 270: 248: 247: 226: 225: 200: 199: 178: 177: 175:natural numbers 153: 152: 107: 106: 73: 72: 69:cardinal number 40: 39: 17: 12: 11: 5: 5013: 5011: 5003: 5002: 4997: 4992: 4982: 4981: 4961: 4960: 4943:Kunen, Kenneth 4940: 4922: 4902: 4899: 4897: 4896: 4871: 4824:(1): 105–110. 4804: 4737: 4730: 4702: 4695: 4662: 4635:(3): 286–297. 4614: 4590: 4562: 4537: 4535: 4532: 4531: 4530: 4523: 4520: 4501: 4497: 4493: 4487: 4482: 4470: 4469: 4466: 4454: 4432: 4410: 4394: 4382: 4360: 4344: 4332: 4310: 4294: 4281: 4255: 4239: 4227: 4205: 4181: 4175: 4162: 4150: 4146: 4142: 4137: 4108: 4103: 4083: 4071: 4067: 4063: 4058: 4035: 4008: 3994: 3991: 3989: 3988: 3974: 3947: 3931: 3916: 3911: 3882: 3877: 3860: 3848: 3826: 3810: 3795: 3789: 3775: 3759: 3753: 3741:often denoted 3727: 3723: 3719: 3702: 3690: 3686: 3682: 3677: 3657: 3641: 3638: 3635: 3632: 3629: 3626: 3624: 3622: 3619: 3616: 3613: 3610: 3607: 3606: 3602: 3598: 3595: 3593: 3589: 3584: 3579: 3576: 3573: 3572: 3563: 3547: 3543: 3540: 3537: 3534: 3513: 3510: 3507: 3504: 3483: 3479: 3476: 3452: 3447: 3443: 3438: 3433: 3428: 3404: 3389: 3376: 3371: 3356: 3350: 3335: 3330: 3326: 3322: 3318: 3292: 3287: 3282: 3278: 3274: 3269: 3242: 3218: 3194: 3168: 3164: 3139: 3133: 3120: 3117: 3114: 3111: 3108: 3083: 3063: 3051: 3035: 3020: 3006: 3003: 2991:limit cardinal 2968: 2964: 2939: 2935: 2930: 2907: 2903: 2880: 2856: 2852: 2848: 2843: 2813: 2810: 2807: 2785: 2781: 2758: 2742:natural number 2715: 2710: 2705: 2701: 2697: 2693: 2689: 2684: 2680: 2675: 2671: 2668: 2659: 2645: 2621: 2617: 2596: 2574: 2570: 2543: 2526:Main article: 2523: 2520: 2508: 2503: 2499: 2495: 2489: 2484: 2474: 2456: 2429: 2424: 2420: 2416: 2411: 2400: 2381: 2355: 2351: 2346: 2342: 2337: 2334: 2331: 2327: 2304: 2300: 2296: 2291: 2287: 2271:Main article: 2268: 2265: 2253: 2245: 2241: 2236: 2232: 2227: 2216: 2198: 2193: 2186: 2182: 2177: 2167: 2154: 2151: 2148: 2145: 2142: 2122: 2119: 2116: 2113: 2110: 2107: 2104: 2079: 2075: 2071: 2066: 2062: 2058: 2055: 2052: 2047: 2043: 2033: 2014: 2010: 2005: 2001: 1994: 1990: 1986: 1983: 1980: 1975: 1971: 1966: 1962: 1955: 1951: 1945: 1940: 1936: 1932: 1927: 1920: 1916: 1911: 1907: 1900: 1896: 1891: 1887: 1882: 1878: 1874: 1869: 1858: 1840: 1836: 1815: 1810: 1806: 1784: 1759: 1756: 1753: 1744: 1741: 1726: 1721: 1715: 1710: 1682: 1677: 1651: 1646: 1642: 1635: 1631: 1627: 1622: 1616: 1612: 1606: 1601: 1593: 1589: 1584: 1580: 1577: 1571: 1564: 1552: 1531: 1526: 1521: 1516: 1513: 1508: 1501: 1497: 1493: 1488: 1482: 1476: 1469: 1465: 1460: 1456: 1449: 1445: 1437: 1433: 1427: 1420: 1416: 1409: 1397: 1382: 1377: 1372: 1365: 1361: 1356: 1352: 1344: 1340: 1335: 1332: 1328: 1324: 1319: 1315: 1307: 1303: 1298: 1294: 1291: 1286: 1280: 1268: 1249: 1244: 1239: 1233: 1208: 1201: 1197: 1192: 1188: 1184: 1180: 1176: 1172: 1169: 1165: 1161: 1156: 1145: 1132: 1129: 1126: 1123: 1120: 1100: 1097: 1094: 1091: 1088: 1054: 1043:, is equal to 1028: 1024: 1019: 998: 994: 990: 987: 966: 942: 938: 934: 931: 908: 904: 900: 895: 891: 887: 883: 879: 858: 855: 832: 827: 822: 817: 813: 803: 788: 784: 757: 732: 731:Uncountability 729: 727: 724: 701: 697: 693: 688: 663: 638: 634: 603: 599: 572: 568: 545: 541: 535: 530: 524: 520: 516: 511: 506: 502: 498: 494: 491: 488: 485: 482: 478: 468: 449: 444: 414: 348: 343: 339: 335: 328: 324: 319: 315: 310: 299: 283: 279: 268:is denoted as 256: 234: 208: 186: 161: 135: 126: 117: 83: 48: 15: 13: 10: 9: 6: 4: 3: 2: 5012: 5001: 4998: 4996: 4993: 4991: 4988: 4987: 4985: 4978: 4977: 4975: 4971: 4967: 4958: 4957:0-444-86839-9 4954: 4950: 4949: 4944: 4941: 4938: 4937:3-540-44085-2 4934: 4930: 4926: 4923: 4920: 4919:0-387-90092-6 4916: 4912: 4908: 4905: 4904: 4900: 4894:, March 2011. 4893: 4892: 4887: 4883: 4878: 4876: 4872: 4867: 4863: 4858: 4853: 4849: 4845: 4840: 4835: 4831: 4827: 4823: 4819: 4815: 4808: 4805: 4800: 4796: 4791: 4786: 4782: 4778: 4773: 4768: 4764: 4760: 4756: 4752: 4748: 4741: 4738: 4733: 4731:9781400881635 4727: 4723: 4719: 4715: 4714: 4706: 4703: 4698: 4696:9781447106036 4692: 4688: 4684: 4680: 4673: 4671: 4669: 4667: 4663: 4658: 4654: 4650: 4646: 4642: 4638: 4634: 4630: 4623: 4621: 4619: 4615: 4610: 4606: 4605: 4600: 4594: 4591: 4580: 4576: 4569: 4567: 4563: 4552: 4548: 4542: 4539: 4533: 4529: 4526: 4525: 4521: 4519: 4517: 4499: 4495: 4491: 4480: 4467: 4399: 4395: 4349: 4345: 4299: 4295: 4270: 4244: 4240: 4163: 4125: 4101: 4092: 4088: 4084: 4024: 4023: 4022: 3992: 3962: 3936: 3932: 3914: 3898: 3880: 3865: 3861: 3815: 3811: 3776: 3707: 3703: 3666: 3662: 3658: 3639: 3636: 3633: 3630: 3625: 3617: 3614: 3611: 3594: 3587: 3577: 3574: 3562: 3541: 3538: 3535: 3532: 3511: 3508: 3505: 3502: 3477: 3474: 3445: 3441: 3436: 3426: 3394: 3390: 3374: 3360: 3357: 3355: 3351: 3328: 3324: 3316: 3285: 3280: 3272: 3166: 3152: 3148: 3144: 3140: 3138: 3134: 3115: 3112: 3109: 3098: 3097:unit interval 3095:(such as the 3072: 3068: 3067:nondegenerate 3064: 3041: 3037: 3036: 3034: 3004: 3002: 3000: 2996: 2992: 2988: 2984: 2966: 2962: 2937: 2933: 2905: 2854: 2846: 2831: 2827: 2811: 2808: 2805: 2783: 2746: 2743: 2739: 2735: 2731: 2713: 2703: 2695: 2687: 2682: 2673: 2669: 2666: 2658: 2619: 2594: 2572: 2559: 2529: 2521: 2506: 2501: 2497: 2493: 2482: 2473: 2471: 2445: 2427: 2422: 2418: 2414: 2399: 2397: 2353: 2349: 2344: 2340: 2335: 2332: 2329: 2325: 2302: 2294: 2289: 2285: 2274: 2266: 2251: 2243: 2234: 2230: 2215: 2191: 2184: 2175: 2166: 2149: 2146: 2143: 2117: 2114: 2111: 2105: 2102: 2077: 2069: 2064: 2056: 2053: 2050: 2045: 2032: 2012: 2003: 1999: 1992: 1984: 1981: 1978: 1973: 1964: 1960: 1953: 1938: 1934: 1925: 1918: 1909: 1905: 1898: 1889: 1885: 1880: 1872: 1857: 1854: 1838: 1813: 1808: 1773: 1769: 1764: 1752: 1750: 1742: 1740: 1719: 1708: 1699: 1675: 1644: 1640: 1633: 1625: 1614: 1610: 1591: 1582: 1575: 1551: 1549: 1524: 1514: 1511: 1499: 1491: 1486: 1474: 1467: 1458: 1454: 1447: 1435: 1425: 1418: 1396: 1380: 1370: 1363: 1354: 1350: 1342: 1333: 1330: 1326: 1322: 1317: 1305: 1296: 1289: 1284: 1267: 1265: 1242: 1237: 1206: 1199: 1190: 1186: 1159: 1144: 1127: 1124: 1121: 1095: 1092: 1089: 1078: 1074: 1073:Dedekind cuts 1070: 1026: 1017: 956: 902: 893: 889: 881: 868: 864: 856: 854: 852: 848: 830: 820: 815: 802: 786: 773: 745: 741: 737: 730: 725: 723: 721: 717: 699: 691: 677:, means that 636: 623: 619: 601: 588: 570: 543: 533: 518: 500: 489: 486: 483: 467: 465: 447: 433: 430:-dimensional 429: 403: 399: 395: 391: 390:open interval 387: 383: 378: 376: 372: 368: 364: 346: 341: 333: 326: 317: 313: 298: 296: 281: 223: 176: 149: 104: 100: 70: 67: 63: 38: 34: 30: 26: 22: 4963: 4962: 4951:. Elsevier. 4946: 4931:. Springer. 4928: 4925:Jech, Thomas 4910: 4901:Bibliography 4889: 4821: 4817: 4807: 4754: 4750: 4740: 4712: 4705: 4678: 4632: 4628: 4602: 4593: 4582:. Retrieved 4578: 4554:. Retrieved 4550: 4541: 4471: 3996: 3416: 3151:Gödel number 3040:real numbers 3008: 2744: 2727: 2558:aleph number 2531: 2443: 2441: 2395: 2276: 2267:Beth numbers 2213: 2094: 2030: 1855: 1765: 1762: 1746: 1697: 1666: 1547: 1545: 1394: 1220: 860: 844: 736:Georg Cantor 734: 557: 466:). That is, 427: 402:equinumerous 397: 393: 385: 381: 379: 363:Georg Cantor 360: 198:. Moreover, 150: 102: 37:real numbers 24: 18: 4907:Paul Halmos 4575:"Continuum" 3704:the set of 2273:Beth number 869:. That is, 746:. That is, 740:cardinality 97:(lowercase 64:. It is an 29:cardinality 4995:Set theory 4984:Categories 4970:PlanetMath 4584:2020-08-12 4556:2020-08-12 4534:References 4124:isomorphic 3961:Borel sets 3814:continuous 3354:Cantor set 2830:cofinality 2738:Paul Cohen 2734:Kurt Gödel 726:Properties 587:aleph-null 21:set theory 4848:0027-8424 4781:0027-8424 4609:EMS Press 4496:ℶ 4021:include: 3897:open sets 3722:→ 3706:sequences 3661:power set 3628:↦ 3597:→ 3578:: 3542:∈ 3524:for some 3478:∈ 3277:ℵ 3273:− 3163:ℵ 2963:ω 2934:ω 2929:ℵ 2902:ℵ 2855:ω 2851:ℵ 2847:≠ 2780:ℵ 2679:ℵ 2667:∄ 2616:ℵ 2569:ℵ 2498:ℶ 2470:real line 2419:ℶ 2350:ℶ 2326:ℶ 2299:ℵ 2286:ℶ 2240:ℵ 2214:and thus 2192:≤ 2181:ℵ 2074:ℵ 2061:ℵ 2057:⋅ 2042:ℵ 2009:ℵ 1989:ℵ 1985:⋅ 1970:ℵ 1950:ℵ 1926:⋅ 1915:ℵ 1906:≤ 1895:ℵ 1886:⋅ 1877:ℵ 1873:≤ 1835:ℵ 1805:ℵ 1768:countable 1630:ℵ 1626:× 1588:ℵ 1496:ℵ 1464:ℵ 1444:ℵ 1432:ℵ 1415:ℵ 1360:ℵ 1339:ℵ 1334:× 1302:ℵ 1196:ℵ 1168:℘ 1023:ℵ 986:℘ 930:℘ 867:power set 812:ℵ 783:ℵ 696:ℵ 633:ℵ 618:aleph-one 598:ℵ 567:ℵ 338:ℵ 323:ℵ 278:ℵ 222:power set 62:continuum 5000:Infinity 4945:, 1980. 4927:, 2003. 4866:16591132 4799:16578557 4611:. 2001 . 4522:See also 4516:beth two 4271:sets in 4164:the set 4085:the set 3071:interval 2954:, where 2444:beth-two 2396:beth-one 66:infinite 4826:Bibcode 4759:Bibcode 4657:1903582 4649:2695360 3663:of the 2981:is the 953:of the 620:). The 365:in his 99:Fraktur 27:is the 4955:  4935:  4917:  4864:  4857:300611 4854:  4846:  4797:  4790:221287 4787:  4779:  4728:  4693:  4655:  4647:  4444:, and 2832:(e.g. 1700:, and 1667:where 1546:where 105:") or 23:, the 4645:JSTOR 3065:any ( 2997:or a 2989:or a 2370:. So 462:(see 404:with 400:) is 4953:ISBN 4933:ISBN 4915:ISBN 4862:PMID 4844:ISSN 4795:PMID 4777:ISSN 4726:ISBN 4691:ISBN 4396:the 4241:the 3933:the 3862:the 3659:the 3391:the 3352:the 3141:the 3135:the 3038:the 2736:and 2704:< 2688:< 2634:and 2317:and 1720:> 890:< 849:and 821:< 651:and 334:> 4968:on 4852:PMC 4834:doi 4785:PMC 4767:doi 4718:doi 4683:doi 4637:doi 4633:109 4400:of 4372:to 4322:to 4245:of 4217:to 4126:to 4122:is 4089:of 3963:in 3937:on 3899:in 3866:on 3838:to 3230:is 3073:in 2920:or 2472:): 2133:to 224:of 35:of 33:set 19:In 4986:: 4909:, 4888:, 4884:, 4874:^ 4860:. 4850:. 4842:. 4832:. 4822:51 4820:. 4816:. 4793:. 4783:. 4775:. 4765:. 4755:50 4753:. 4749:. 4724:. 4716:. 4689:. 4665:^ 4653:MR 4651:. 4643:. 4631:. 4617:^ 4607:. 4601:. 4577:. 4565:^ 4549:. 4518:) 4422:, 3986:). 3001:. 2771:= 2560:, 2398:: 1890:10 1739:. 1266:: 853:. 801:: 774:, 4976:. 4959:. 4939:. 4868:. 4836:: 4828:: 4801:. 4769:: 4761:: 4734:. 4720:: 4699:. 4685:: 4659:. 4639:: 4587:. 4559:. 4514:( 4500:2 4492:= 4486:c 4481:2 4453:R 4431:Q 4409:N 4381:R 4359:R 4331:R 4309:R 4293:. 4280:R 4254:R 4226:R 4204:R 4180:R 4174:R 4149:) 4145:R 4141:( 4136:P 4107:R 4102:2 4087:2 4082:) 4070:) 4066:R 4062:( 4057:P 4034:R 4007:c 3973:R 3946:R 3929:) 3915:n 3910:R 3881:n 3876:R 3847:R 3825:R 3794:N 3788:R 3773:) 3758:N 3752:Z 3739:, 3726:Z 3718:N 3689:) 3685:N 3681:( 3676:P 3640:i 3637:b 3634:+ 3631:a 3621:) 3618:b 3615:, 3612:a 3609:( 3601:C 3588:2 3583:R 3575:f 3559:. 3546:R 3539:b 3536:, 3533:a 3512:i 3509:b 3506:+ 3503:a 3482:C 3475:c 3465:. 3451:c 3446:= 3442:| 3437:2 3432:R 3427:| 3403:C 3375:n 3370:R 3348:. 3334:c 3329:= 3325:| 3321:C 3317:| 3305:. 3291:c 3286:= 3281:0 3268:c 3255:, 3241:c 3217:R 3206:. 3193:R 3181:. 3167:0 3131:) 3119:] 3116:1 3113:, 3110:0 3107:[ 3082:R 3050:R 3019:c 2967:1 2938:1 2906:1 2879:c 2842:c 2812:1 2809:= 2806:n 2784:n 2757:c 2745:n 2714:. 2709:c 2700:| 2696:A 2692:| 2683:0 2674:: 2670:A 2644:c 2620:0 2595:A 2573:1 2542:c 2507:. 2502:2 2494:= 2488:c 2483:2 2455:R 2428:. 2423:1 2415:= 2410:c 2380:c 2354:k 2345:2 2341:= 2336:1 2333:+ 2330:k 2303:0 2295:= 2290:0 2252:. 2244:0 2235:2 2231:= 2226:c 2197:c 2185:0 2176:2 2153:} 2150:7 2147:, 2144:3 2141:{ 2121:} 2118:1 2115:, 2112:0 2109:{ 2106:= 2103:2 2078:0 2070:= 2065:0 2054:4 2051:+ 2046:0 2013:0 2004:2 2000:= 1993:0 1982:4 1979:+ 1974:0 1965:2 1961:= 1954:0 1944:) 1939:4 1935:2 1931:( 1919:0 1910:2 1899:0 1881:0 1868:c 1839:0 1814:, 1809:0 1783:N 1725:c 1714:c 1709:2 1698:R 1681:c 1676:2 1650:c 1645:2 1641:= 1634:0 1621:c 1615:2 1611:= 1605:c 1600:) 1592:0 1583:2 1579:( 1576:= 1570:c 1563:c 1548:n 1530:c 1525:= 1520:c 1515:n 1512:= 1507:c 1500:0 1492:= 1487:n 1481:c 1475:= 1468:0 1459:n 1455:= 1448:0 1436:0 1426:= 1419:0 1408:c 1381:. 1376:c 1371:= 1364:0 1355:2 1351:= 1343:0 1331:2 1327:2 1323:= 1318:2 1314:) 1306:0 1297:2 1293:( 1290:= 1285:2 1279:c 1248:c 1243:= 1238:2 1232:c 1207:. 1200:0 1191:2 1187:= 1183:| 1179:) 1175:N 1171:( 1164:| 1160:= 1155:c 1131:) 1128:2 1125:, 1122:1 1119:[ 1099:) 1096:1 1093:, 1090:0 1087:[ 1053:c 1027:0 1018:2 997:) 993:N 989:( 965:N 941:) 937:N 933:( 907:| 903:A 899:| 894:2 886:| 882:A 878:| 831:. 826:c 816:0 787:0 756:c 700:1 692:= 687:c 662:c 637:0 616:( 602:1 585:( 571:0 544:. 540:| 534:n 529:R 523:| 519:= 515:| 510:R 505:| 501:= 497:| 493:) 490:b 487:, 484:a 481:( 477:| 448:n 443:R 428:n 413:R 398:b 396:, 394:a 392:( 386:b 382:a 347:. 342:0 327:0 318:2 314:= 309:c 282:0 255:N 233:N 207:R 185:N 160:R 134:| 125:R 116:| 103:c 101:" 82:c 47:R

Index

set theory
cardinality
set
real numbers
continuum
infinite
cardinal number
Fraktur
natural numbers
power set
0 {\displaystyle \aleph _{0}}
Georg Cantor
uncountability proof
diagonal argument
bijective functions
open interval
equinumerous
Euclidean space
space filling curve
aleph-null
aleph-one
continuum hypothesis
cannot be proven
Zermelo–Fraenkel set theory
Georg Cantor
cardinality
uncountably infinite
natural numbers
Cantor's first uncountability proof
Cantor's diagonal argument

Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.

↑