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Epsilon number

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91: 2258: 926: 50: 688: 153: 2004: 1629: 2667: 487: 510: 2253:{\displaystyle \omega ^{\omega ^{\omega ^{\varepsilon _{0}+1}}}=\omega ^{{\varepsilon _{0}}^{\omega }}=\omega ^{{\varepsilon _{0}}^{1+\omega }}=\omega ^{(\varepsilon _{0}\cdot {\varepsilon _{0}}^{\omega })}={(\omega ^{\varepsilon _{0}})}^{{\varepsilon _{0}}^{\omega }}={\varepsilon _{0}}^{{\varepsilon _{0}}^{\omega }}\,,} 2833:. It might appear that this is the non-constructive equivalent of the constructive definition using iterated exponentiation; but the two definitions are equally non-constructive at steps indexed by limit ordinals, which represent transfinite recursion of a higher order than taking the supremum of an exponential series. 2442: 1440: 1434: 1998: 4239: 4083: 2506: 335: 683:{\displaystyle \varepsilon _{1},\varepsilon _{2},\ldots ,\varepsilon _{\omega },\varepsilon _{\omega +1},\ldots ,\varepsilon _{\varepsilon _{0}},\ldots ,\varepsilon _{\varepsilon _{1}},\ldots ,\varepsilon _{\varepsilon _{\varepsilon _{\cdot _{\cdot _{\cdot }}}}},\ldots } 1861: 3004: 2305: 1738: 1624:{\displaystyle \varepsilon _{\beta }=\sup \left\lbrace {\varepsilon _{\beta -1}+1},\omega ^{\varepsilon _{\beta -1}+1},\omega ^{\omega ^{\varepsilon _{\beta -1}+1}},\omega ^{\omega ^{\omega ^{\varepsilon _{\beta -1}+1}}},\ldots \right\rbrace \,,} 1200: 1317: 3303: 3114: 1867: 4094: 240:. Consequently, they are not reachable from 0 via a finite series of applications of the chosen exponential map and of "weaker" operations like addition and multiplication. The original epsilon numbers were introduced by 2662:{\displaystyle \varepsilon _{\beta }=\sup \left\{1,\varepsilon _{\beta -1},\varepsilon _{\beta -1}^{\varepsilon _{\beta -1}},\varepsilon _{\beta -1}^{\varepsilon _{\beta -1}^{\varepsilon _{\beta -1}}},\dots \right\}.} 3960: 3556:
is represented by a tree containing a root and a single leaf.) An order on the set of finite rooted trees is defined recursively: we first order the subtrees joined to the root in decreasing order, and then use
1085: 482:{\displaystyle \varepsilon _{0}=\omega ^{\omega ^{\omega ^{\cdot ^{\cdot ^{\cdot }}}}}=\sup \left\{\omega ,\omega ^{\omega },\omega ^{\omega ^{\omega }},\omega ^{\omega ^{\omega ^{\omega }}},\dots \right\}\,,} 3409: 2831: 3954:
It is natural to consider any fixed point of this expanded map to be an epsilon number, whether or not it happens to be strictly an ordinal number. Some examples of non-ordinal epsilon numbers are
296: 2736: 3834: 3757: 3162: 3037: 2928: 1770: 1271: 3521: 3475: 3357: 3217: 3634: 3056: 2896: 2786: 2697: 2472: 3941: 2437:{\displaystyle \varepsilon _{1}=\sup \left\{1,\varepsilon _{0},{\varepsilon _{0}}^{\varepsilon _{0}},{\varepsilon _{0}}^{{\varepsilon _{0}}^{\varepsilon _{0}}},\ldots \right\}.} 4269: 2865: 2288: 1028: 1309: 1682: 3554: 1429:{\displaystyle \varepsilon _{0}=\sup \left\lbrace 1,\omega ,\omega ^{\omega },\omega ^{\omega ^{\omega }},\omega ^{\omega ^{\omega ^{\omega }}},\ldots \right\rbrace \,,} 1138: 2498: 1993:{\displaystyle \omega ^{\omega ^{\varepsilon _{0}+1}}=\omega ^{(\varepsilon _{0}\cdot \omega )}={(\omega ^{\varepsilon _{0}})}^{\omega }=\varepsilon _{0}^{\omega }\,,} 1675: 1131: 4234:{\displaystyle \varepsilon _{1/2}=\left\{\varepsilon _{0}+1,\omega ^{\varepsilon _{0}+1},\ldots \mid \varepsilon _{1}-1,\omega ^{\varepsilon _{1}-1},\ldots \right\}.} 3907: 3429: 2916: 2759: 1758: 1649: 1220: 1105: 3222: 3689:
for progressively larger ordinals α (including, by this rarefied form of transfinite recursion, limit ordinals), with progressively larger least fixed points
2741:
Since the epsilon numbers are an unbounded subclass of the ordinal numbers, they are enumerated using the ordinal numbers themselves. For any ordinal number
4279:. Conway goes on to define a broader class of "irreducible" surreal numbers that includes the epsilon numbers as a particularly interesting subclass. 841: 171: 4078:{\displaystyle \varepsilon _{-1}=\left\{0,1,\omega ,\omega ^{\omega },\ldots \mid \varepsilon _{0}-1,\omega ^{\varepsilon _{0}-1},\ldots \right\}} 17: 4386: 3477:
in turn has a similar Cantor normal form. We obtain the finite rooted tree representing α by joining the roots of the trees representing
1034: 753: 4526: 3362: 2791: 4502: 3888:
provided a number of examples of concepts that had natural extensions from the ordinals to the surreals. One such function is the
1282: 264: 2702: 3797: 3720: 3134: 3009: 1856:{\displaystyle \omega ^{\varepsilon _{0}+1}=\omega ^{\varepsilon _{0}}\cdot \omega ^{1}=\varepsilon _{0}\cdot \omega \,,} 4334: 973: 806: 207: 189: 134: 112: 77: 1243: 955: 105: 4379: 3480: 3434: 3316: 3189: 3043: 947: 63: 4427: 3760: 3606: 951: 737: 3523:
to a new root. (This has the consequence that the number 0 is represented by a single root while the number
4345: 2874: 2764: 2675: 2450: 3948: 3913: 4466: 4372: 3164:, which means that the Cantor normal form is not very useful for epsilon numbers. The ordinals less than 2999:{\displaystyle \varepsilon _{\omega }=\sup\{\varepsilon _{0},\varepsilon _{1},\varepsilon _{2},\ldots \}} 1733:{\displaystyle \varepsilon _{\beta }=\sup \lbrace \varepsilon _{\delta }\mid \delta <\beta \rbrace } 4247: 3173:, however, can be usefully described by their Cantor normal forms, which leads to a representation of 2843: 2699:
is a fixed point not only of base ω exponentiation but also of base δ exponentiation for all ordinals
2266: 996: 4559: 3183: 1288: 1278: 233: 4584: 3526: 936: 707:
ordinals also exist, along with uncountable epsilon numbers whose index is an uncountable ordinal.
507:
Larger ordinal fixed points of the exponential map are indexed by ordinal subscripts, resulting in
99: 1195:{\displaystyle \alpha ^{\beta }=\sup \lbrace \alpha ^{\delta }\mid 0<\delta <\beta \rbrace } 4395: 4293: 3702:. The least ordinal not reachable from 0 by this procedure—i. e., the least ordinal α for which 3561:
on these ordered sequences of subtrees. In this way the set of all finite rooted trees becomes a
940: 4341: 3582: 987: 741: 720: 116: 3298:{\displaystyle \alpha =\omega ^{\beta _{1}}+\omega ^{\beta _{2}}+\cdots +\omega ^{\beta _{k}}} 3109:{\displaystyle \alpha \geq 1\Rightarrow \varepsilon _{\omega _{\alpha }}=\omega _{\alpha }\,.} 2477: 1654: 1110: 4483: 3892: 3558: 3414: 757: 724: 326: 2901: 2744: 1743: 1634: 1205: 1090: 4545: 4456: 4446: 3944: 3889: 3876: 8: 69: 38: 3636:
form a normal function, whose fixed points form a normal function; this is known as the
2788:
is the least epsilon number (fixed point of the exponential map) not already in the set
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system, consisting of all surreals that are fixed points of the base ω exponential map
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of this ordering (it is in fact the least ordinal with this property, and as such, in
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This article is about a type of ordinal in mathematics. For the physical constant
4406: 3637: 3598: 3050: 3047: 1274: 771: 3881: 3769:. In a set theory where such an ordinal can be proved to exist, one has a map 3310: 786: 249: 4578: 1223: 4364: 3943:; this mapping generalises naturally to include all surreal numbers in its 3586: 782: 767:, is used as a measure of the strength of the theory of Peano arithmetic). 761: 241: 704: 221: 2836:
The following facts about epsilon numbers are straightforward to prove:
3562: 2922: 2868: 700: 501: 3657:). In the notation of the Veblen hierarchy, the epsilon mapping is 925: 3836:; these are all still epsilon numbers, as they lie in the image of 1080:{\displaystyle \alpha ^{\beta }=\alpha ^{\beta -1}\cdot \alpha \,,} 497: 256: 745: 3404:{\displaystyle \alpha >\beta _{1}\geq \cdots \geq \beta _{k}} 2826:{\displaystyle \{\varepsilon _{\delta }\mid \delta <\beta \}} 1311:, these fixed points are precisely the ordinal epsilon numbers. 777:
A more general class of epsilon numbers has been identified by
2672:
In particular, whether or not the index β is a limit ordinal,
2290:, is obtained by starting from 0 and exponentiating with base 2925:
set of epsilon numbers is an epsilon number; so for instance
1230:
From this definition, it follows that for any fixed ordinal
504:
in the case of the von Neumann representation of ordinals.
2871:, being a countable union of countable ordinals; in fact, 3947:, which in turn provides a natural generalisation of the 3585:, which represents decreasing sequences of ordinals as a 2474:
indexed by any ordinal that has an immediate predecessor
3119: 291:{\displaystyle \varepsilon =\omega ^{\varepsilon },\,} 4250: 4097: 3963: 3916: 3895: 3800: 3723: 3609: 3529: 3483: 3437: 3417: 3365: 3319: 3225: 3192: 3137: 3059: 3012: 2931: 2904: 2877: 2846: 2794: 2767: 2747: 2731:{\displaystyle 1<\delta <\varepsilon _{\beta }} 2705: 2678: 2509: 2480: 2453: 2308: 2269: 2007: 1870: 1773: 1746: 1685: 1657: 1637: 1443: 1320: 1291: 1246: 1208: 1141: 1113: 1093: 1037: 999: 770:
Many larger epsilon numbers can be defined using the
703:, as is any epsilon number whose index is countable. 513: 338: 267: 3829:{\displaystyle \alpha \mapsto \varphi _{\alpha }(0)} 3752:{\displaystyle \alpha \mapsto \varphi _{\alpha }(0)} 3717:, or equivalently the first fixed point of the map 3581:This representation is related to the proof of the 3157:{\displaystyle \varepsilon =\omega ^{\varepsilon }} 3032:{\displaystyle \beta \mapsto \varepsilon _{\beta }} 162:
may be too technical for most readers to understand
4350:(2nd ed.), PWN – Polish Scientific Publishers 4263: 4233: 4077: 3935: 3901: 3828: 3751: 3628: 3548: 3515: 3469: 3423: 3403: 3351: 3297: 3211: 3156: 3108: 3031: 2998: 2910: 2890: 2859: 2825: 2780: 2753: 2730: 2691: 2661: 2492: 2466: 2436: 2282: 2252: 1992: 1855: 1752: 1732: 1669: 1643: 1623: 1428: 1303: 1265: 1214: 1194: 1125: 1099: 1079: 1022: 682: 481: 325:), which can be viewed as the "limit" obtained by 290: 4576: 2945: 2523: 2322: 1699: 1457: 1334: 1155: 393: 4527:the theories of iterated inductive definitions 1266:{\displaystyle \beta \mapsto \alpha ^{\beta }} 906:, and his delta numbers are those of the form 756:, show that Peano arithmetic cannot prove the 4380: 3678:Continuing in this vein, one can define maps 3516:{\displaystyle \beta _{1},\ldots ,\beta _{k}} 3470:{\displaystyle \beta _{1},\ldots ,\beta _{k}} 3352:{\displaystyle \beta _{1},\ldots ,\beta _{k}} 2263:a different sequence with the same supremum, 301:in which ω is the smallest infinite ordinal. 4394: 2993: 2948: 2820: 2795: 1727: 1702: 1189: 1158: 3212:{\displaystyle \alpha <\varepsilon _{0}} 954:. Unsourced material may be challenged and 329:from a sequence of smaller limit ordinals: 78:Learn how and when to remove these messages 4387: 4373: 4354: 4340: 3603:The fixed points of the "epsilon mapping" 900:. His gamma numbers are those of the form 802: 3666:, and its fixed points are enumerated by 3629:{\displaystyle x\mapsto \varepsilon _{x}} 3102: 3006:is an epsilon number. Thus, the mapping 2246: 1986: 1849: 1617: 1422: 1073: 1016: 974:Learn how and when to remove this message 475: 287: 232:whose defining property is that they are 208:Learn how and when to remove this message 190:Learn how and when to remove this message 174:, without removing the technical details. 135:Learn how and when to remove this message 4359:. Göttingen: Vandenhoeck & Ruprecht. 98:This article includes a list of general 842:multiplicatively indecomposable ordinal 14: 4577: 1283:fixed-point lemma for normal functions 4368: 4314:Subsystems of Second-order Arithmetic 2891:{\displaystyle \varepsilon _{\beta }} 2840:Although it is quite a large number, 2781:{\displaystyle \varepsilon _{\beta }} 2692:{\displaystyle \varepsilon _{\beta }} 2467:{\displaystyle \varepsilon _{\beta }} 754:Gödel's second incompleteness theorem 172:make it understandable to non-experts 3936:{\displaystyle n\mapsto \omega ^{n}} 3869: 952:adding citations to reliable sources 919: 915: 872:, and epsilon numbers to be numbers 146: 84: 43: 3592: 24: 723:proofs, because for many purposes 104:it lacks sufficient corresponding 25: 4596: 4503:Takeuti–Feferman–Buchholz ordinal 4244:There is a natural way to define 3866:that enumerates epsilon numbers. 3773:that enumerates the fixed points 807:additively indecomposable ordinal 59:This article has multiple issues. 4264:{\displaystyle \varepsilon _{n}} 3640:(the Veblen functions with base 2860:{\displaystyle \varepsilon _{0}} 2283:{\displaystyle \varepsilon _{1}} 1023:{\displaystyle \alpha ^{0}=1\,,} 924: 151: 89: 48: 2921:The union (or supremum) of any 1304:{\displaystyle \alpha =\omega } 67:or discuss these issues on the 4306: 3920: 3823: 3817: 3804: 3746: 3740: 3727: 3613: 3069: 3016: 2500:can be constructed similarly. 2447:Generally, the epsilon number 2182: 2162: 2152: 2117: 1958: 1938: 1928: 1909: 1277:, so it has arbitrarily large 1250: 13: 1: 4534: < ω‍ 4357:Grundbegriffe der Mengenlehre 4299: 3549:{\displaystyle 1=\omega ^{0}} 1651:has an immediate predecessor 1107:has an immediate predecessor 18:Epsilon numbers (mathematics) 4525:Proof-theoretic ordinals of 4355:Hessenberg, Gerhard (1906). 4347:Cardinal and ordinal numbers 3880:, the classic exposition on 2898:is countable if and only if 748:to prove the consistency of 710:The smallest epsilon number 7: 4282: 3186:, as follows. Any ordinal 986:The standard definition of 805:defined gamma numbers (see 738:Gentzen's consistency proof 27:Type of transfinite numbers 10: 4601: 4548: ≥ ω‍ 3596: 3182:as the ordered set of all 304:The least such ordinal is 29: 4560:First uncountable ordinal 4402: 4271:for every surreal number 3411:, uniquely determined by 3128:Any epsilon number ε has 840:, and delta numbers (see 500:, which is equivalent to 4428:Feferman–Schütte ordinal 4396:Large countable ordinals 3761:Feferman–Schütte ordinal 2493:{\displaystyle \beta -1} 1670:{\displaystyle \beta -1} 1126:{\displaystyle \beta -1} 4467:Bachmann–Howard ordinal 4294:Large countable ordinal 3902:{\displaystyle \omega } 3857:, including of the map 3431:. Each of the ordinals 3424:{\displaystyle \alpha } 3219:has Cantor normal form 727:is only required up to 321:(chiefly American), or 119:more precise citations. 4407:First infinite ordinal 4329:(1976) Academic Press 4275:, and the map remains 4265: 4235: 4079: 3937: 3903: 3830: 3753: 3630: 3550: 3517: 3471: 3425: 3405: 3353: 3299: 3213: 3158: 3110: 3053:is an epsilon number. 3033: 3000: 2912: 2911:{\displaystyle \beta } 2892: 2861: 2827: 2782: 2755: 2754:{\displaystyle \beta } 2732: 2693: 2663: 2494: 2468: 2438: 2284: 2254: 1994: 1857: 1754: 1753:{\displaystyle \beta } 1734: 1671: 1645: 1644:{\displaystyle \beta } 1625: 1430: 1305: 1267: 1216: 1215:{\displaystyle \beta } 1196: 1127: 1101: 1100:{\displaystyle \beta } 1081: 1024: 988:ordinal exponentiation 684: 483: 292: 4266: 4236: 4080: 3951:for surreal numbers. 3938: 3904: 3831: 3754: 3631: 3551: 3518: 3472: 3426: 3406: 3354: 3300: 3214: 3159: 3111: 3039:is a normal function. 3034: 3001: 2913: 2893: 2862: 2828: 2783: 2756: 2733: 2694: 2664: 2495: 2469: 2439: 2285: 2255: 1995: 1858: 1755: 1735: 1672: 1646: 1626: 1431: 1306: 1268: 1217: 1197: 1128: 1102: 1082: 1025: 725:transfinite induction 685: 484: 327:transfinite recursion 293: 4546:Nonrecursive ordinal 4457:large Veblen ordinal 4447:small Veblen ordinal 4327:On Numbers and Games 4312:Stephen G. Simpson, 4248: 4095: 3961: 3914: 3893: 3877:On Numbers and Games 3798: 3721: 3607: 3527: 3481: 3435: 3415: 3363: 3317: 3223: 3190: 3135: 3057: 3010: 2929: 2902: 2875: 2844: 2792: 2765: 2745: 2703: 2676: 2507: 2478: 2451: 2306: 2267: 2005: 1868: 1771: 1744: 1683: 1655: 1635: 1441: 1318: 1289: 1244: 1206: 1139: 1111: 1091: 1035: 997: 948:improve this section 511: 336: 265: 228:are a collection of 4532:Computable ordinals 3559:lexicographic order 3184:finite rooted trees 3120:Representation of ε 2644: 2642: 2589: 1985: 1760:is a limit ordinal. 742:Goodstein's theorem 317:(chiefly British), 230:transfinite numbers 39:Vacuum permittivity 4484:Buchholz's ordinal 4342:Sierpiński, Wacław 4339:Section XIV.20 of 4289:Ordinal arithmetic 4261: 4231: 4075: 3949:Cantor normal form 3933: 3899: 3886:John Horton Conway 3826: 3749: 3626: 3546: 3513: 3467: 3421: 3401: 3359:are ordinals with 3349: 3295: 3209: 3154: 3130:Cantor normal form 3106: 3029: 2996: 2908: 2888: 2857: 2823: 2778: 2751: 2728: 2689: 2659: 2609: 2593: 2556: 2490: 2464: 2434: 2280: 2250: 1990: 1971: 1853: 1750: 1730: 1667: 1641: 1621: 1426: 1301: 1263: 1212: 1192: 1123: 1097: 1077: 1020: 779:John Horton Conway 680: 479: 288: 246:ordinal arithmetic 244:in the context of 4572: 4571: 4437:Ackermann ordinal 3870:Surreal ε numbers 984: 983: 976: 916:Ordinal ε numbers 803:Hessenberg (1906) 740:and the proof of 255:that satisfy the 218: 217: 210: 200: 199: 192: 145: 144: 137: 82: 16:(Redirected from 4592: 4556: 4555: 4542: 4541: 4389: 4382: 4375: 4366: 4365: 4360: 4351: 4317: 4310: 4277:order-preserving 4270: 4268: 4267: 4262: 4260: 4259: 4240: 4238: 4237: 4232: 4227: 4223: 4216: 4215: 4208: 4207: 4184: 4183: 4165: 4164: 4157: 4156: 4133: 4132: 4115: 4114: 4110: 4084: 4082: 4081: 4076: 4074: 4070: 4063: 4062: 4055: 4054: 4031: 4030: 4012: 4011: 3976: 3975: 3942: 3940: 3939: 3934: 3932: 3931: 3908: 3906: 3905: 3900: 3865: 3856: 3846: 3835: 3833: 3832: 3827: 3816: 3815: 3793: 3786: 3779: 3772: 3768: 3758: 3756: 3755: 3750: 3739: 3738: 3716: 3701: 3688: 3674: 3665: 3656: 3638:Veblen hierarchy 3635: 3633: 3632: 3627: 3625: 3624: 3593:Veblen hierarchy 3577: 3567:order isomorphic 3563:well-ordered set 3555: 3553: 3552: 3547: 3545: 3544: 3522: 3520: 3519: 3514: 3512: 3511: 3493: 3492: 3476: 3474: 3473: 3468: 3466: 3465: 3447: 3446: 3430: 3428: 3427: 3422: 3410: 3408: 3407: 3402: 3400: 3399: 3381: 3380: 3358: 3356: 3355: 3350: 3348: 3347: 3329: 3328: 3304: 3302: 3301: 3296: 3294: 3293: 3292: 3291: 3268: 3267: 3266: 3265: 3248: 3247: 3246: 3245: 3218: 3216: 3215: 3210: 3208: 3207: 3181: 3172: 3163: 3161: 3160: 3155: 3153: 3152: 3115: 3113: 3112: 3107: 3101: 3100: 3088: 3087: 3086: 3085: 3038: 3036: 3035: 3030: 3028: 3027: 3005: 3003: 3002: 2997: 2986: 2985: 2973: 2972: 2960: 2959: 2941: 2940: 2917: 2915: 2914: 2909: 2897: 2895: 2894: 2889: 2887: 2886: 2866: 2864: 2863: 2858: 2856: 2855: 2832: 2830: 2829: 2824: 2807: 2806: 2787: 2785: 2784: 2779: 2777: 2776: 2760: 2758: 2757: 2752: 2737: 2735: 2734: 2729: 2727: 2726: 2698: 2696: 2695: 2690: 2688: 2687: 2668: 2666: 2665: 2660: 2655: 2651: 2643: 2641: 2640: 2639: 2623: 2607: 2588: 2587: 2586: 2570: 2552: 2551: 2519: 2518: 2499: 2497: 2496: 2491: 2473: 2471: 2470: 2465: 2463: 2462: 2443: 2441: 2440: 2435: 2430: 2426: 2419: 2418: 2417: 2416: 2415: 2414: 2404: 2403: 2402: 2390: 2389: 2388: 2374: 2373: 2372: 2371: 2361: 2360: 2359: 2345: 2344: 2318: 2317: 2298: 2289: 2287: 2286: 2281: 2279: 2278: 2259: 2257: 2256: 2251: 2245: 2244: 2243: 2242: 2237: 2236: 2235: 2223: 2222: 2221: 2207: 2206: 2205: 2204: 2199: 2198: 2197: 2185: 2181: 2180: 2179: 2178: 2156: 2155: 2151: 2150: 2145: 2144: 2143: 2129: 2128: 2108: 2107: 2106: 2105: 2094: 2093: 2092: 2073: 2072: 2071: 2070: 2065: 2064: 2063: 2044: 2043: 2042: 2041: 2040: 2039: 2032: 2031: 1999: 1997: 1996: 1991: 1984: 1979: 1967: 1966: 1961: 1957: 1956: 1955: 1954: 1932: 1931: 1921: 1920: 1900: 1899: 1898: 1897: 1890: 1889: 1862: 1860: 1859: 1854: 1842: 1841: 1829: 1828: 1816: 1815: 1814: 1813: 1796: 1795: 1788: 1787: 1759: 1757: 1756: 1751: 1739: 1737: 1736: 1731: 1714: 1713: 1695: 1694: 1676: 1674: 1673: 1668: 1650: 1648: 1647: 1642: 1630: 1628: 1627: 1622: 1616: 1612: 1605: 1604: 1603: 1602: 1601: 1600: 1593: 1592: 1559: 1558: 1557: 1556: 1549: 1548: 1520: 1519: 1512: 1511: 1488: 1481: 1480: 1453: 1452: 1435: 1433: 1432: 1427: 1421: 1417: 1410: 1409: 1408: 1407: 1406: 1405: 1383: 1382: 1381: 1380: 1363: 1362: 1330: 1329: 1310: 1308: 1307: 1302: 1272: 1270: 1269: 1264: 1262: 1261: 1236: 1221: 1219: 1218: 1213: 1201: 1199: 1198: 1193: 1170: 1169: 1151: 1150: 1132: 1130: 1129: 1124: 1106: 1104: 1103: 1098: 1086: 1084: 1083: 1078: 1066: 1065: 1047: 1046: 1029: 1027: 1026: 1021: 1009: 1008: 990:with base α is: 979: 972: 968: 965: 959: 928: 920: 911: 905: 899: 888: 878: 871: 860: 850: 844:) to be numbers 839: 829: 815: 809:) to be numbers 798: 765:ordinal analysis 758:well-foundedness 750:Peano arithmetic 735: 719:appears in many 718: 698: 689: 687: 686: 681: 673: 672: 671: 670: 669: 668: 667: 666: 665: 664: 626: 625: 624: 623: 600: 599: 598: 597: 574: 573: 555: 554: 536: 535: 523: 522: 495: 488: 486: 485: 480: 474: 470: 463: 462: 461: 460: 459: 458: 436: 435: 434: 433: 416: 415: 389: 388: 387: 386: 385: 384: 383: 382: 381: 380: 348: 347: 297: 295: 294: 289: 283: 282: 213: 206: 195: 188: 184: 181: 175: 155: 154: 147: 140: 133: 129: 126: 120: 115:this article by 106:inline citations 93: 92: 85: 74: 52: 51: 44: 21: 4600: 4599: 4595: 4594: 4593: 4591: 4590: 4589: 4585:Ordinal numbers 4575: 4574: 4573: 4568: 4554: 4551: 4550: 4549: 4540: 4537: 4536: 4535: 4521: 4519: 4498: 4492: 4479: 4433: 4424: 4416:Epsilon numbers 4398: 4393: 4363: 4321: 4320: 4311: 4307: 4302: 4285: 4255: 4251: 4249: 4246: 4245: 4203: 4199: 4198: 4194: 4179: 4175: 4152: 4148: 4147: 4143: 4128: 4124: 4123: 4119: 4106: 4102: 4098: 4096: 4093: 4092: 4050: 4046: 4045: 4041: 4026: 4022: 4007: 4003: 3984: 3980: 3968: 3964: 3962: 3959: 3958: 3927: 3923: 3915: 3912: 3911: 3894: 3891: 3890: 3882:surreal numbers 3872: 3864: 3858: 3855: 3848: 3845: 3837: 3811: 3807: 3799: 3796: 3795: 3792: 3788: 3785: 3781: 3778: 3774: 3770: 3767: 3763: 3734: 3730: 3722: 3719: 3718: 3711: 3703: 3699: 3690: 3687: 3679: 3673: 3667: 3664: 3658: 3647: 3641: 3620: 3616: 3608: 3605: 3604: 3601: 3599:Veblen function 3595: 3587:graph-theoretic 3576: 3570: 3540: 3536: 3528: 3525: 3524: 3507: 3503: 3488: 3484: 3482: 3479: 3478: 3461: 3457: 3442: 3438: 3436: 3433: 3432: 3416: 3413: 3412: 3395: 3391: 3376: 3372: 3364: 3361: 3360: 3343: 3339: 3324: 3320: 3318: 3315: 3314: 3287: 3283: 3282: 3278: 3261: 3257: 3256: 3252: 3241: 3237: 3236: 3232: 3224: 3221: 3220: 3203: 3199: 3191: 3188: 3187: 3180: 3174: 3171: 3165: 3148: 3144: 3136: 3133: 3132: 3126: 3124:by rooted trees 3123: 3096: 3092: 3081: 3077: 3076: 3072: 3058: 3055: 3054: 3044:initial ordinal 3023: 3019: 3011: 3008: 3007: 2981: 2977: 2968: 2964: 2955: 2951: 2936: 2932: 2930: 2927: 2926: 2903: 2900: 2899: 2882: 2878: 2876: 2873: 2872: 2851: 2847: 2845: 2842: 2841: 2802: 2798: 2793: 2790: 2789: 2772: 2768: 2766: 2763: 2762: 2746: 2743: 2742: 2722: 2718: 2704: 2701: 2700: 2683: 2679: 2677: 2674: 2673: 2629: 2625: 2624: 2613: 2608: 2597: 2576: 2572: 2571: 2560: 2541: 2537: 2530: 2526: 2514: 2510: 2508: 2505: 2504: 2479: 2476: 2475: 2458: 2454: 2452: 2449: 2448: 2410: 2406: 2405: 2398: 2394: 2393: 2392: 2391: 2384: 2380: 2379: 2378: 2367: 2363: 2362: 2355: 2351: 2350: 2349: 2340: 2336: 2329: 2325: 2313: 2309: 2307: 2304: 2303: 2297: 2291: 2274: 2270: 2268: 2265: 2264: 2238: 2231: 2227: 2226: 2225: 2224: 2217: 2213: 2212: 2211: 2200: 2193: 2189: 2188: 2187: 2186: 2174: 2170: 2169: 2165: 2161: 2160: 2146: 2139: 2135: 2134: 2133: 2124: 2120: 2116: 2112: 2095: 2088: 2084: 2083: 2082: 2081: 2077: 2066: 2059: 2055: 2054: 2053: 2052: 2048: 2027: 2023: 2022: 2018: 2017: 2013: 2012: 2008: 2006: 2003: 2002: 1980: 1975: 1962: 1950: 1946: 1945: 1941: 1937: 1936: 1916: 1912: 1908: 1904: 1885: 1881: 1880: 1876: 1875: 1871: 1869: 1866: 1865: 1837: 1833: 1824: 1820: 1809: 1805: 1804: 1800: 1783: 1779: 1778: 1774: 1772: 1769: 1768: 1745: 1742: 1741: 1709: 1705: 1690: 1686: 1684: 1681: 1680: 1656: 1653: 1652: 1636: 1633: 1632: 1582: 1578: 1577: 1573: 1572: 1568: 1567: 1563: 1538: 1534: 1533: 1529: 1528: 1524: 1501: 1497: 1496: 1492: 1470: 1466: 1465: 1464: 1460: 1448: 1444: 1442: 1439: 1438: 1401: 1397: 1396: 1392: 1391: 1387: 1376: 1372: 1371: 1367: 1358: 1354: 1341: 1337: 1325: 1321: 1319: 1316: 1315: 1290: 1287: 1286: 1275:normal function 1257: 1253: 1245: 1242: 1241: 1231: 1207: 1204: 1203: 1165: 1161: 1146: 1142: 1140: 1137: 1136: 1112: 1109: 1108: 1092: 1089: 1088: 1055: 1051: 1042: 1038: 1036: 1033: 1032: 1004: 1000: 998: 995: 994: 980: 969: 963: 960: 945: 929: 918: 907: 901: 890: 880: 873: 862: 852: 845: 831: 817: 810: 790: 772:Veblen function 762:proof-theoretic 744:). Its use by 734: 728: 717: 711: 697: 691: 690:. The ordinal 660: 656: 655: 651: 650: 646: 645: 641: 640: 636: 619: 615: 614: 610: 593: 589: 588: 584: 563: 559: 550: 546: 531: 527: 518: 514: 512: 509: 508: 493: 454: 450: 449: 445: 444: 440: 429: 425: 424: 420: 411: 407: 400: 396: 376: 372: 371: 367: 366: 362: 361: 357: 356: 352: 343: 339: 337: 334: 333: 311: 278: 274: 266: 263: 262: 250:ordinal numbers 248:; they are the 238:exponential map 226:epsilon numbers 214: 203: 202: 201: 196: 185: 179: 176: 168:help improve it 165: 156: 152: 141: 130: 124: 121: 111:Please help to 110: 94: 90: 53: 49: 42: 35: 28: 23: 22: 15: 12: 11: 5: 4598: 4588: 4587: 4570: 4569: 4567: 4566: 4557: 4552: 4543: 4538: 4529: 4523: 4515: 4513: 4500: 4494: 4490: 4481: 4477: 4464: 4454: 4444: 4434: 4431: 4425: 4422: 4413: 4403: 4400: 4399: 4392: 4391: 4384: 4377: 4369: 4362: 4361: 4352: 4337: 4322: 4319: 4318: 4304: 4303: 4301: 4298: 4297: 4296: 4291: 4284: 4281: 4258: 4254: 4242: 4241: 4230: 4226: 4222: 4219: 4214: 4211: 4206: 4202: 4197: 4193: 4190: 4187: 4182: 4178: 4174: 4171: 4168: 4163: 4160: 4155: 4151: 4146: 4142: 4139: 4136: 4131: 4127: 4122: 4118: 4113: 4109: 4105: 4101: 4086: 4085: 4073: 4069: 4066: 4061: 4058: 4053: 4049: 4044: 4040: 4037: 4034: 4029: 4025: 4021: 4018: 4015: 4010: 4006: 4002: 3999: 3996: 3993: 3990: 3987: 3983: 3979: 3974: 3971: 3967: 3930: 3926: 3922: 3919: 3898: 3871: 3868: 3862: 3853: 3841: 3825: 3822: 3819: 3814: 3810: 3806: 3803: 3790: 3783: 3776: 3765: 3748: 3745: 3742: 3737: 3733: 3729: 3726: 3707: 3694: 3683: 3671: 3662: 3645: 3623: 3619: 3615: 3612: 3597:Main article: 3594: 3591: 3574: 3543: 3539: 3535: 3532: 3510: 3506: 3502: 3499: 3496: 3491: 3487: 3464: 3460: 3456: 3453: 3450: 3445: 3441: 3420: 3398: 3394: 3390: 3387: 3384: 3379: 3375: 3371: 3368: 3346: 3342: 3338: 3335: 3332: 3327: 3323: 3311:natural number 3290: 3286: 3281: 3277: 3274: 3271: 3264: 3260: 3255: 3251: 3244: 3240: 3235: 3231: 3228: 3206: 3202: 3198: 3195: 3178: 3169: 3151: 3147: 3143: 3140: 3125: 3121: 3118: 3117: 3116: 3105: 3099: 3095: 3091: 3084: 3080: 3075: 3071: 3068: 3065: 3062: 3040: 3026: 3022: 3018: 3015: 2995: 2992: 2989: 2984: 2980: 2976: 2971: 2967: 2963: 2958: 2954: 2950: 2947: 2944: 2939: 2935: 2919: 2907: 2885: 2881: 2854: 2850: 2822: 2819: 2816: 2813: 2810: 2805: 2801: 2797: 2775: 2771: 2750: 2725: 2721: 2717: 2714: 2711: 2708: 2686: 2682: 2670: 2669: 2658: 2654: 2650: 2647: 2638: 2635: 2632: 2628: 2622: 2619: 2616: 2612: 2606: 2603: 2600: 2596: 2592: 2585: 2582: 2579: 2575: 2569: 2566: 2563: 2559: 2555: 2550: 2547: 2544: 2540: 2536: 2533: 2529: 2525: 2522: 2517: 2513: 2489: 2486: 2483: 2461: 2457: 2445: 2444: 2433: 2429: 2425: 2422: 2413: 2409: 2401: 2397: 2387: 2383: 2377: 2370: 2366: 2358: 2354: 2348: 2343: 2339: 2335: 2332: 2328: 2324: 2321: 2316: 2312: 2295: 2277: 2273: 2261: 2260: 2249: 2241: 2234: 2230: 2220: 2216: 2210: 2203: 2196: 2192: 2184: 2177: 2173: 2168: 2164: 2159: 2154: 2149: 2142: 2138: 2132: 2127: 2123: 2119: 2115: 2111: 2104: 2101: 2098: 2091: 2087: 2080: 2076: 2069: 2062: 2058: 2051: 2047: 2038: 2035: 2030: 2026: 2021: 2016: 2011: 2000: 1989: 1983: 1978: 1974: 1970: 1965: 1960: 1953: 1949: 1944: 1940: 1935: 1930: 1927: 1924: 1919: 1915: 1911: 1907: 1903: 1896: 1893: 1888: 1884: 1879: 1874: 1863: 1852: 1848: 1845: 1840: 1836: 1832: 1827: 1823: 1819: 1812: 1808: 1803: 1799: 1794: 1791: 1786: 1782: 1777: 1762: 1761: 1749: 1729: 1726: 1723: 1720: 1717: 1712: 1708: 1704: 1701: 1698: 1693: 1689: 1678: 1666: 1663: 1660: 1640: 1620: 1615: 1611: 1608: 1599: 1596: 1591: 1588: 1585: 1581: 1576: 1571: 1566: 1562: 1555: 1552: 1547: 1544: 1541: 1537: 1532: 1527: 1523: 1518: 1515: 1510: 1507: 1504: 1500: 1495: 1491: 1487: 1484: 1479: 1476: 1473: 1469: 1463: 1459: 1456: 1451: 1447: 1436: 1425: 1420: 1416: 1413: 1404: 1400: 1395: 1390: 1386: 1379: 1375: 1370: 1366: 1361: 1357: 1353: 1350: 1347: 1344: 1340: 1336: 1333: 1328: 1324: 1300: 1297: 1294: 1260: 1256: 1252: 1249: 1228: 1227: 1211: 1191: 1188: 1185: 1182: 1179: 1176: 1173: 1168: 1164: 1160: 1157: 1154: 1149: 1145: 1134: 1122: 1119: 1116: 1096: 1076: 1072: 1069: 1064: 1061: 1058: 1054: 1050: 1045: 1041: 1030: 1019: 1015: 1012: 1007: 1003: 982: 981: 932: 930: 923: 917: 914: 787:surreal number 732: 715: 695: 679: 676: 663: 659: 654: 649: 644: 639: 635: 632: 629: 622: 618: 613: 609: 606: 603: 596: 592: 587: 583: 580: 577: 572: 569: 566: 562: 558: 553: 549: 545: 542: 539: 534: 530: 526: 521: 517: 490: 489: 478: 473: 469: 466: 457: 453: 448: 443: 439: 432: 428: 423: 419: 414: 410: 406: 403: 399: 395: 392: 379: 375: 370: 365: 360: 355: 351: 346: 342: 319:epsilon naught 315:epsilon nought 309: 299: 298: 286: 281: 277: 273: 270: 216: 215: 198: 197: 159: 157: 150: 143: 142: 97: 95: 88: 83: 57: 56: 54: 47: 33: 26: 9: 6: 4: 3: 2: 4597: 4586: 4583: 4582: 4580: 4565: 4561: 4558: 4547: 4544: 4533: 4530: 4528: 4524: 4518: 4512: 4508: 4504: 4501: 4497: 4489: 4485: 4482: 4476: 4472: 4468: 4465: 4462: 4458: 4455: 4452: 4448: 4445: 4442: 4438: 4435: 4429: 4426: 4421: 4417: 4414: 4412: 4408: 4405: 4404: 4401: 4397: 4390: 4385: 4383: 4378: 4376: 4371: 4370: 4367: 4358: 4353: 4349: 4348: 4343: 4338: 4336: 4335:0-12-186350-6 4332: 4328: 4325:J.H. Conway, 4324: 4323: 4316:(2009, p.387) 4315: 4309: 4305: 4295: 4292: 4290: 4287: 4286: 4280: 4278: 4274: 4256: 4252: 4228: 4224: 4220: 4217: 4212: 4209: 4204: 4200: 4195: 4191: 4188: 4185: 4180: 4176: 4172: 4169: 4166: 4161: 4158: 4153: 4149: 4144: 4140: 4137: 4134: 4129: 4125: 4120: 4116: 4111: 4107: 4103: 4099: 4091: 4090: 4089: 4071: 4067: 4064: 4059: 4056: 4051: 4047: 4042: 4038: 4035: 4032: 4027: 4023: 4019: 4016: 4013: 4008: 4004: 4000: 3997: 3994: 3991: 3988: 3985: 3981: 3977: 3972: 3969: 3965: 3957: 3956: 3955: 3952: 3950: 3946: 3928: 3924: 3917: 3910: 3896: 3887: 3883: 3879: 3878: 3867: 3861: 3851: 3844: 3840: 3820: 3812: 3808: 3801: 3762: 3743: 3735: 3731: 3724: 3715: 3710: 3706: 3697: 3693: 3686: 3682: 3676: 3670: 3661: 3655: 3651: 3644: 3639: 3621: 3617: 3610: 3600: 3590: 3588: 3584: 3583:hydra theorem 3579: 3573: 3568: 3564: 3560: 3541: 3537: 3533: 3530: 3508: 3504: 3500: 3497: 3494: 3489: 3485: 3462: 3458: 3454: 3451: 3448: 3443: 3439: 3418: 3396: 3392: 3388: 3385: 3382: 3377: 3373: 3369: 3366: 3344: 3340: 3336: 3333: 3330: 3325: 3321: 3312: 3308: 3288: 3284: 3279: 3275: 3272: 3269: 3262: 3258: 3253: 3249: 3242: 3238: 3233: 3229: 3226: 3204: 3200: 3196: 3193: 3185: 3177: 3168: 3149: 3145: 3141: 3138: 3131: 3103: 3097: 3093: 3089: 3082: 3078: 3073: 3066: 3063: 3060: 3052: 3049: 3045: 3041: 3024: 3020: 3013: 2990: 2987: 2982: 2978: 2974: 2969: 2965: 2961: 2956: 2952: 2942: 2937: 2933: 2924: 2920: 2918:is countable. 2905: 2883: 2879: 2870: 2852: 2848: 2839: 2838: 2837: 2834: 2817: 2814: 2811: 2808: 2803: 2799: 2773: 2769: 2748: 2739: 2723: 2719: 2715: 2712: 2709: 2706: 2684: 2680: 2656: 2652: 2648: 2645: 2636: 2633: 2630: 2626: 2620: 2617: 2614: 2610: 2604: 2601: 2598: 2594: 2590: 2583: 2580: 2577: 2573: 2567: 2564: 2561: 2557: 2553: 2548: 2545: 2542: 2538: 2534: 2531: 2527: 2520: 2515: 2511: 2503: 2502: 2501: 2487: 2484: 2481: 2459: 2455: 2431: 2427: 2423: 2420: 2411: 2407: 2399: 2395: 2385: 2381: 2375: 2368: 2364: 2356: 2352: 2346: 2341: 2337: 2333: 2330: 2326: 2319: 2314: 2310: 2302: 2301: 2300: 2294: 2275: 2271: 2247: 2239: 2232: 2228: 2218: 2214: 2208: 2201: 2194: 2190: 2175: 2171: 2166: 2157: 2147: 2140: 2136: 2130: 2125: 2121: 2113: 2109: 2102: 2099: 2096: 2089: 2085: 2078: 2074: 2067: 2060: 2056: 2049: 2045: 2036: 2033: 2028: 2024: 2019: 2014: 2009: 2001: 1987: 1981: 1976: 1972: 1968: 1963: 1951: 1947: 1942: 1933: 1925: 1922: 1917: 1913: 1905: 1901: 1894: 1891: 1886: 1882: 1877: 1872: 1864: 1850: 1846: 1843: 1838: 1834: 1830: 1825: 1821: 1817: 1810: 1806: 1801: 1797: 1792: 1789: 1784: 1780: 1775: 1767: 1766: 1765: 1747: 1724: 1721: 1718: 1715: 1710: 1706: 1696: 1691: 1687: 1679: 1664: 1661: 1658: 1638: 1618: 1613: 1609: 1606: 1597: 1594: 1589: 1586: 1583: 1579: 1574: 1569: 1564: 1560: 1553: 1550: 1545: 1542: 1539: 1535: 1530: 1525: 1521: 1516: 1513: 1508: 1505: 1502: 1498: 1493: 1489: 1485: 1482: 1477: 1474: 1471: 1467: 1461: 1454: 1449: 1445: 1437: 1423: 1418: 1414: 1411: 1402: 1398: 1393: 1388: 1384: 1377: 1373: 1368: 1364: 1359: 1355: 1351: 1348: 1345: 1342: 1338: 1331: 1326: 1322: 1314: 1313: 1312: 1298: 1295: 1292: 1284: 1280: 1276: 1258: 1254: 1247: 1240: 1234: 1225: 1224:limit ordinal 1209: 1186: 1183: 1180: 1177: 1174: 1171: 1166: 1162: 1152: 1147: 1143: 1135: 1120: 1117: 1114: 1094: 1074: 1070: 1067: 1062: 1059: 1056: 1052: 1048: 1043: 1039: 1031: 1017: 1013: 1010: 1005: 1001: 993: 992: 991: 989: 978: 975: 967: 964:February 2023 957: 953: 949: 943: 942: 938: 933:This section 931: 927: 922: 921: 913: 910: 904: 898: 894: 887: 883: 876: 870: 866: 859: 855: 848: 843: 838: 834: 828: 824: 820: 813: 808: 804: 800: 797: 793: 788: 784: 780: 775: 773: 768: 766: 763: 759: 755: 752:, along with 751: 747: 743: 739: 731: 726: 722: 714: 708: 706: 702: 694: 677: 674: 661: 657: 652: 647: 642: 637: 633: 630: 627: 620: 616: 611: 607: 604: 601: 594: 590: 585: 581: 578: 575: 570: 567: 564: 560: 556: 551: 547: 543: 540: 537: 532: 528: 524: 519: 515: 505: 503: 499: 476: 471: 467: 464: 455: 451: 446: 441: 437: 430: 426: 421: 417: 412: 408: 404: 401: 397: 390: 377: 373: 368: 363: 358: 353: 349: 344: 340: 332: 331: 330: 328: 324: 320: 316: 312: 308: 302: 284: 279: 275: 271: 268: 261: 260: 259: 258: 254: 251: 247: 243: 239: 235: 231: 227: 223: 212: 209: 194: 191: 183: 173: 169: 163: 160:This article 158: 149: 148: 139: 136: 128: 118: 114: 108: 107: 101: 96: 87: 86: 81: 79: 72: 71: 66: 65: 60: 55: 46: 45: 40: 36: 19: 4563: 4516: 4510: 4506: 4495: 4487: 4474: 4470: 4460: 4450: 4440: 4419: 4415: 4410: 4356: 4346: 4326: 4313: 4308: 4272: 4243: 4087: 3953: 3875: 3873: 3859: 3849: 3842: 3838: 3713: 3708: 3704: 3695: 3691: 3684: 3680: 3677: 3668: 3659: 3653: 3649: 3642: 3602: 3580: 3571: 3306: 3175: 3166: 3127: 2835: 2740: 2671: 2446: 2292: 2262: 1763: 1279:fixed points 1232: 1229: 985: 970: 961: 946:Please help 934: 908: 902: 896: 892: 885: 881: 874: 868: 864: 857: 853: 846: 836: 832: 826: 822: 818: 811: 801: 795: 791: 783:Donald Knuth 776: 769: 729: 712: 709: 692: 506: 491: 323:epsilon zero 322: 318: 314: 313:(pronounced 306: 305: 303: 300: 252: 242:Georg Cantor 237: 234:fixed points 225: 219: 204: 186: 180:January 2023 177: 161: 131: 122: 103: 75: 68: 62: 61:Please help 58: 31: 3048:uncountable 1740:, whenever 1202:, whenever 705:Uncountable 222:mathematics 117:introducing 4300:References 3847:for every 879:such that 851:such that 816:such that 100:references 64:improve it 4253:ε 4221:… 4210:− 4201:ε 4196:ω 4186:− 4177:ε 4173:∣ 4170:… 4150:ε 4145:ω 4126:ε 4100:ε 4068:… 4057:− 4048:ε 4043:ω 4033:− 4024:ε 4020:∣ 4017:… 4009:ω 4005:ω 3998:ω 3970:− 3966:ε 3925:ω 3921:↦ 3897:ω 3813:α 3809:φ 3805:↦ 3802:α 3794:, ... of 3736:α 3732:φ 3728:↦ 3725:α 3618:ε 3614:↦ 3565:which is 3538:ω 3505:β 3498:… 3486:β 3459:β 3452:… 3440:β 3419:α 3393:β 3389:≥ 3386:⋯ 3383:≥ 3374:β 3367:α 3341:β 3334:… 3322:β 3285:β 3280:ω 3273:⋯ 3259:β 3254:ω 3239:β 3234:ω 3227:α 3201:ε 3194:α 3150:ε 3146:ω 3139:ε 3098:α 3094:ω 3083:α 3079:ω 3074:ε 3070:⇒ 3064:≥ 3061:α 3025:β 3021:ε 3017:↦ 3014:β 2991:… 2979:ε 2966:ε 2953:ε 2938:ω 2934:ε 2923:non-empty 2906:β 2884:β 2880:ε 2869:countable 2867:is still 2849:ε 2818:β 2812:δ 2809:∣ 2804:δ 2800:ε 2774:β 2770:ε 2749:β 2724:β 2720:ε 2713:δ 2685:β 2681:ε 2649:… 2634:− 2631:β 2627:ε 2618:− 2615:β 2611:ε 2602:− 2599:β 2595:ε 2581:− 2578:β 2574:ε 2565:− 2562:β 2558:ε 2546:− 2543:β 2539:ε 2516:β 2512:ε 2485:− 2482:β 2460:β 2456:ε 2424:… 2408:ε 2396:ε 2382:ε 2365:ε 2353:ε 2338:ε 2311:ε 2299:instead: 2272:ε 2240:ω 2229:ε 2215:ε 2202:ω 2191:ε 2172:ε 2167:ω 2148:ω 2137:ε 2131:⋅ 2122:ε 2114:ω 2103:ω 2086:ε 2079:ω 2068:ω 2057:ε 2050:ω 2025:ε 2020:ω 2015:ω 2010:ω 1982:ω 1973:ε 1964:ω 1948:ε 1943:ω 1926:ω 1923:⋅ 1914:ε 1906:ω 1883:ε 1878:ω 1873:ω 1847:ω 1844:⋅ 1835:ε 1822:ω 1818:⋅ 1807:ε 1802:ω 1781:ε 1776:ω 1748:β 1725:β 1719:δ 1716:∣ 1711:δ 1707:ε 1692:β 1688:ε 1662:− 1659:β 1639:β 1610:… 1587:− 1584:β 1580:ε 1575:ω 1570:ω 1565:ω 1543:− 1540:β 1536:ε 1531:ω 1526:ω 1506:− 1503:β 1499:ε 1494:ω 1475:− 1472:β 1468:ε 1450:β 1446:ε 1415:… 1403:ω 1399:ω 1394:ω 1389:ω 1378:ω 1374:ω 1369:ω 1360:ω 1356:ω 1349:ω 1323:ε 1299:ω 1293:α 1259:β 1255:α 1251:↦ 1248:β 1210:β 1187:β 1181:δ 1172:∣ 1167:δ 1163:α 1148:β 1144:α 1118:− 1115:β 1095:β 1071:α 1068:⋅ 1060:− 1057:β 1053:α 1044:β 1040:α 1002:α 935:does not 889:whenever 861:whenever 830:whenever 721:induction 701:countable 699:is still 678:… 662:⋅ 658:⋅ 653:⋅ 648:ε 643:ε 638:ε 631:… 617:ε 612:ε 605:… 591:ε 586:ε 579:… 565:ω 561:ε 552:ω 548:ε 541:… 529:ε 516:ε 502:set union 468:… 456:ω 452:ω 447:ω 442:ω 431:ω 427:ω 422:ω 413:ω 409:ω 402:ω 378:⋅ 374:⋅ 369:⋅ 364:ω 359:ω 354:ω 341:ε 280:ε 276:ω 269:ε 70:talk page 4579:Category 4344:(1965), 4283:See also 3759:—is the 3051:cardinal 1764:Because 1285:. When 498:supremum 257:equation 125:May 2021 4430: Γ 3046:of any 1281:by the 1239:mapping 956:removed 941:sources 891:1 < 863:0 < 785:in the 746:Gentzen 736:(as in 496:is the 236:of an 166:Please 113:improve 4562:  4505:  4486:  4469:  4459:  4449:  4439:  4418:  4409:  4333:  3945:domain 3712:(0) = 3589:game. 3305:where 1237:, the 1235:> 1 877:> 2 849:> 1 814:> 0 492:where 224:, the 102:, but 37:, see 3309:is a 1631:when 1273:is a 1222:is a 1087:when 895:< 867:< 835:< 4331:ISBN 4088:and 3909:-map 3652:) = 3370:> 3313:and 3197:< 3042:The 2815:< 2716:< 2710:< 1722:< 1184:< 1178:< 939:any 937:cite 781:and 4478:Ω+1 4463:(Ω) 4453:(Ω) 4443:(Ω) 3874:In 3852:≤ Γ 3700:(0) 3569:to 2946:sup 2524:sup 2323:sup 1700:sup 1458:sup 1335:sup 1156:sup 950:by 494:sup 394:sup 220:In 170:to 4581:: 4520:+1 4493:(Ω 3884:, 3787:, 3780:, 3698:+1 3675:. 3578:. 2761:, 2738:. 912:. 884:= 856:= 854:αδ 825:= 821:+ 799:. 794:→ 774:. 73:. 4564:Ω 4553:1 4539:1 4522:) 4517:ω 4514:Ω 4511:ε 4509:( 4507:ψ 4499:) 4496:ω 4491:0 4488:ψ 4480:) 4475:ε 4473:( 4471:ψ 4461:θ 4451:θ 4441:θ 4432:0 4423:0 4420:ε 4411:ω 4388:e 4381:t 4374:v 4273:n 4257:n 4229:. 4225:} 4218:, 4213:1 4205:1 4192:, 4189:1 4181:1 4167:, 4162:1 4159:+ 4154:0 4141:, 4138:1 4135:+ 4130:0 4121:{ 4117:= 4112:2 4108:/ 4104:1 4072:} 4065:, 4060:1 4052:0 4039:, 4036:1 4028:0 4014:, 4001:, 3995:, 3992:1 3989:, 3986:0 3982:{ 3978:= 3973:1 3929:n 3918:n 3863:1 3860:φ 3854:0 3850:β 3843:β 3839:φ 3824:) 3821:0 3818:( 3791:2 3789:Γ 3784:1 3782:Γ 3777:0 3775:Γ 3771:Γ 3766:0 3764:Γ 3747:) 3744:0 3741:( 3714:α 3709:α 3705:φ 3696:α 3692:φ 3685:α 3681:φ 3672:2 3669:φ 3663:1 3660:φ 3654:ω 3650:α 3648:( 3646:0 3643:φ 3622:x 3611:x 3575:0 3572:ε 3542:0 3534:= 3531:1 3509:k 3501:, 3495:, 3490:1 3463:k 3455:, 3449:, 3444:1 3397:k 3378:1 3345:k 3337:, 3331:, 3326:1 3307:k 3289:k 3276:+ 3270:+ 3263:2 3250:+ 3243:1 3230:= 3205:0 3179:0 3176:ε 3170:0 3167:ε 3142:= 3122:0 3104:. 3090:= 3067:1 2994:} 2988:, 2983:2 2975:, 2970:1 2962:, 2957:0 2949:{ 2943:= 2853:0 2821:} 2796:{ 2707:1 2657:. 2653:} 2646:, 2637:1 2621:1 2605:1 2591:, 2584:1 2568:1 2554:, 2549:1 2535:, 2532:1 2528:{ 2521:= 2488:1 2432:. 2428:} 2421:, 2412:0 2400:0 2386:0 2376:, 2369:0 2357:0 2347:, 2342:0 2334:, 2331:1 2327:{ 2320:= 2315:1 2296:0 2293:ε 2276:1 2248:, 2233:0 2219:0 2209:= 2195:0 2183:) 2176:0 2163:( 2158:= 2153:) 2141:0 2126:0 2118:( 2110:= 2100:+ 2097:1 2090:0 2075:= 2061:0 2046:= 2037:1 2034:+ 2029:0 1988:, 1977:0 1969:= 1959:) 1952:0 1939:( 1934:= 1929:) 1918:0 1910:( 1902:= 1895:1 1892:+ 1887:0 1851:, 1839:0 1831:= 1826:1 1811:0 1798:= 1793:1 1790:+ 1785:0 1728:} 1703:{ 1697:= 1677:. 1665:1 1619:, 1614:} 1607:, 1598:1 1595:+ 1590:1 1561:, 1554:1 1551:+ 1546:1 1522:, 1517:1 1514:+ 1509:1 1490:, 1486:1 1483:+ 1478:1 1462:{ 1455:= 1424:, 1419:} 1412:, 1385:, 1365:, 1352:, 1346:, 1343:1 1339:{ 1332:= 1327:0 1296:= 1233:α 1226:. 1190:} 1175:0 1159:{ 1153:= 1133:. 1121:1 1075:, 1063:1 1049:= 1018:, 1014:1 1011:= 1006:0 977:) 971:( 966:) 962:( 958:. 944:. 909:ω 903:ω 897:ε 893:α 886:ε 882:α 875:ε 869:δ 865:α 858:δ 847:δ 837:γ 833:α 827:γ 823:γ 819:α 812:γ 796:ω 792:x 733:0 730:ε 716:0 713:ε 696:0 693:ε 675:, 634:, 628:, 621:1 608:, 602:, 595:0 582:, 576:, 571:1 568:+ 557:, 544:, 538:, 533:2 525:, 520:1 477:, 472:} 465:, 438:, 418:, 405:, 398:{ 391:= 350:= 345:0 310:0 307:ε 285:, 272:= 253:ε 211:) 205:( 193:) 187:( 182:) 178:( 164:. 138:) 132:( 127:) 123:( 109:. 80:) 76:( 41:. 34:0 32:ε 20:)

Index

Epsilon numbers (mathematics)
Vacuum permittivity
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references
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mathematics
transfinite numbers
fixed points
Georg Cantor
ordinal arithmetic
ordinal numbers
equation
transfinite recursion
supremum
set union
countable
Uncountable
induction
transfinite induction
Gentzen's consistency proof
Goodstein's theorem

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