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Computably enumerable set

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A computable enumeration of the set of all Turing machines halting on a fixed input: Simulate all Turing machines (enumerated on vertical axis) step by step (horizontal axis), using the shown diagonalization scheduling. If a machine terminates, print its number. This way, the number of each
420: 718:. Diophantine sets predate recursion theory and are therefore historically the first way to describe these sets (although this equivalence was only remarked more than three decades after the introduction of computably enumerable sets). 688: 319: 1110: 888: 1388:, the definition corresponding to domains has been found to be more natural. Other texts use the definition in terms of enumerations, which is equivalent for computably enumerable sets. 1285: 963: 1166: 920: 526: 1627: 303: 203: 1317: 999: 146:
this by running the algorithm, but if the number is not in the set, the algorithm runs forever, and no information is returned. A set that is "completely decidable" is a
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is computably enumerable, but it is not true that every computably enumerable set is computable. For computable sets, the algorithm must also say if an input is
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of a total computable function, is common in contemporary texts. This choice is motivated by the fact that in generalized recursion theories, such as
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The Diophantine characterizations of a computably enumerable set, while not as straightforward or intuitive as the first definitions, were found by
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terminating machine is eventually printed. In the example, the algorithm prints "9, 13, 4, 15, 12, 18, 6, 2, 8, 0, ..."
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The set of all provable sentences in an effectively presented axiomatic system is a computably enumerable set.
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of the arithmetical hierarchy. The complexity class of co-computably-enumerable sets is denoted co-RE.
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of a computably enumerable set under a partial computable function is a computably enumerable set.
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The equivalence of semidecidability and enumerability can be obtained by the technique of
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is computably enumerable. Equivalently, a set is co-r.e. if and only if it is at level
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is computably enumerable. This set encodes the problem of deciding a function value.
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such that the set of input numbers for which the algorithm halts is exactly
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There is a polynomial from the integers to the integers such that the set
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is sometimes used. More precisely, if a number is in the set, one can
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in the set – this is not required of computably enumerable sets.
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is infinite, repetition of values may be necessary in this case.
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is defined) is computably enumerable (cf. picture for a fixed
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The Theory of Recursive Functions and Effective Computability
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is a partial computable function if and only if the graph of
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Downey, Rodney G.; Hirschfeldt, Denis R. (29 October 2010).
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are often used, even in print, instead of the full phrase.
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Soare, Robert I. Recursively enumerable sets and degrees.
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is the range of a total computable function, or empty. If
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is the domain (co-range) of a partial computable function.
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contains exactly the non-negative numbers in its range.
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is computably enumerable if and only if there is some
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The definition of a computably enumerable set as the
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as it describes the input parameters for which each
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The following are all equivalent properties of a set
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Recursively enumerable sets and degrees. 1119:from the natural numbers into the natural numbers, 1311: 1279: 1240: 1160: 1104: 1028: 993: 957: 914: 882: 819: 682: 414: 297: 197: 772:states that every computably enumerable set is a 448:is infinite, the function can be chosen to be 437:is the range of a partial computable function. 1520: 1341:Some pairs of computably enumerable sets are 790:are computably enumerable but not computable. 783:are computably enumerable but not computable. 173:containing all computably enumerable sets is 134:is infinite, this algorithm will run forever. 8: 1155: 1134: 1099: 1043: 909: 897: 877: 849: 837: 834: 523:ranging over the natural numbers such that 2346: 1941: 1709: 1527: 1513: 1505: 138:The first condition suggests why the term 1303: 1298: 1292: 1267: 1266: 1264: 1233: 1132: 1078: 1041: 1021: 976: 970: 937: 931: 895: 859: 832: 812: 528: 386: 374: 351: 338: 321: 289: 284: 278: 189: 188: 186: 724: 483:with integer coefficients and variables 181:of c.e. sets under inclusion is denoted 1419: 1380:of a partial function, rather than the 1280:{\displaystyle \mathbb {N} \setminus T} 1271: 1176:) is defined, is computably enumerable. 958:{\displaystyle \phi _{i}(x)\downarrow } 759:is a computably enumerable subset of a 312:There is a partial computable function 1221:) are computably enumerable sets. The 1161:{\displaystyle \langle x,f(x)\rangle } 1430:Algorithmic Randomness and Complexity 1036:of the computable functions, the set 827:of the computable functions, the set 150:. The second condition suggests why 7: 1193:are computably enumerable sets then 714:as part of the negative solution to 1481:Perspectives in Mathematical Logic. 915:{\displaystyle \langle i,x\rangle } 262:is computably enumerable. That is, 1295: 542: 281: 25: 1127:, that is, the set of all pairs 776:(the converse is trivially true). 3246: 1403:Recursively enumerable language 1369:which yields an enumeration of 757:recursively enumerable language 298:{\displaystyle \Sigma _{1}^{0}} 167:computational complexity theory 1152: 1146: 1090: 1084: 988: 982: 952: 949: 943: 874: 871: 865: 674: 665: 605: 599: 539: 332: 326: 198:{\displaystyle {\mathcal {E}}} 1: 3207:History of mathematical logic 217:of natural numbers is called 55:recursively enumerable (r.e.) 3132:Primitive recursive function 1501:84 (1978), no. 6, 1149–1181. 1312:{\displaystyle \Pi _{1}^{0}} 994:{\displaystyle \phi _{i}(x)} 461:primitive recursive function 51:computably enumerable (c.e.) 1338:are computably enumerable. 223:partial computable function 177:. In recursion theory, the 154:is used. The abbreviations 3294: 2196:Schröder–Bernstein theorem 1923:Monadic predicate calculus 1582:Foundations of mathematics 29: 27:Mathematical logic concept 18:Recursively enumerable set 3242: 3229:Philosophy of mathematics 3178:Automated theorem proving 2349: 2303:Von Neumann–Bernays–Gödel 1944: 1115:Given a partial function 99:algorithm that enumerates 1250:co-computably-enumerable 1016:Given a Gödel numbering 1005:). This set encodes the 2879:Self-verifying theories 2700:Tarski's axiomatization 1651:Tarski's undefinability 1646:incompleteness theorems 1219:Cantor pairing function 924:Cantor pairing function 716:Hilbert's Tenth Problem 377:undefined/does not halt 241:Equivalent formulations 3253:Mathematics portal 2864:Proof of impossibility 2512:propositional variable 1822:Propositional calculus 1499:Bull. Amer. Math. Soc. 1408:Arithmetical hierarchy 1334:and the complement of 1313: 1281: 1242: 1162: 1106: 1030: 995: 959: 916: 884: 821: 801:computably enumerable. 770:Matiyasevich's theorem 731: 684: 479:There is a polynomial 416: 307:arithmetical hierarchy 299: 199: 3278:Theory of computation 3122:Kolmogorov complexity 3075:Computably enumerable 2975:Model complete theory 2767:Principia Mathematica 1827:Propositional formula 1656:Banach–Tarski paradox 1343:effectively separable 1314: 1282: 1243: 1163: 1107: 1031: 1029:{\displaystyle \phi } 996: 960: 917: 885: 822: 820:{\displaystyle \phi } 728: 685: 417: 300: 219:computably enumerable 200: 152:computably enumerable 3273:Computability theory 3070:Church–Turing thesis 3057:Computability theory 2266:continuum hypothesis 1784:Square of opposition 1642:Gödel's completeness 1355:Church–Turing thesis 1330:if and only if both 1291: 1263: 1232: 1131: 1040: 1020: 969: 930: 894: 831: 811: 527: 320: 277: 249:of natural numbers: 185: 39:computability theory 3224:Mathematical object 3115:P versus NP problem 3080:Computable function 2874:Reverse mathematics 2800:Logical consequence 2677:primitive recursive 2672:elementary function 2445:Free/bound variable 2298:Tarski–Grothendieck 1817:Logical connectives 1747:Logical equivalence 1597:Logical consequence 1308: 294: 75:Turing-recognizable 63:partially decidable 3022:Transfer principle 2985:Semantics of logic 2970:Categorical theory 2946:Non-standard model 2460:Logical connective 1587:Information theory 1536:Mathematical logic 1386:α-recursion theory 1345:and some are not. 1309: 1294: 1277: 1238: 1158: 1102: 1026: 991: 955: 912: 880: 817: 732: 680: 463:or empty. Even if 459:is the range of a 412: 407: 391: 379: 356: 305:(referring to the 295: 280: 195: 93:Or, equivalently, 3260: 3259: 3192:Abstract category 2995:Theories of truth 2805:Rule of inference 2795:Natural deduction 2776: 2775: 2321: 2320: 2026:Cartesian product 1931: 1930: 1837:Many-valued logic 1812:Boolean functions 1695:Russell's paradox 1670:diagonal argument 1567:First-order logic 1440:978-0-387-68441-3 1361:, and thus a set 1353:According to the 1241:{\displaystyle T} 736: 735: 712:Yuri Matiyasevich 598: 395: 390: 383: 378: 360: 355: 253:Semidecidability: 209:Formal definition 16:(Redirected from 3285: 3251: 3250: 3202:History of logic 3197:Category of sets 3090:Decision problem 2869:Ordinal analysis 2810:Sequent calculus 2708:Boolean algebras 2648: 2647: 2622: 2593:logical/constant 2347: 2333: 2256:Zermelo–Fraenkel 2007:Set operations: 1942: 1879: 1710: 1690:Löwenheim–Skolem 1577:Formal semantics 1529: 1522: 1515: 1506: 1486:, Berlin, 1987. 1445: 1444: 1424: 1318: 1316: 1315: 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1668: and  1644: and  1632: and  1631: 1626:Theorems ( 1621: 1538: 1533: 1484:Springer-Verlag 1449: 1448: 1441: 1426: 1425: 1421: 1416: 1398:RE (complexity) 1394: 1351: 1289: 1288: 1261: 1260: 1230: 1229: 1183: 1129: 1128: 1074: 1050: 1046: 1038: 1037: 1018: 1017: 1007:halting problem 972: 967: 966: 933: 928: 927: 892: 891: 855: 829: 828: 809: 808: 806:Gödel numbering 774:Diophantine set 761:formal language 741: 525: 524: 406: 405: 384: 371: 370: 349: 339: 318: 317: 275: 274: 243: 211: 183: 182: 129: 122: 115: 101:the members of 47:natural numbers 35: 28: 23: 22: 15: 12: 11: 5: 3291: 3289: 3281: 3280: 3275: 3265: 3264: 3258: 3257: 3243: 3240: 3239: 3237: 3236: 3231: 3226: 3221: 3216: 3215: 3214: 3204: 3199: 3194: 3185: 3180: 3175: 3170: 3168:Abstract logic 3164: 3162: 3158: 3157: 3155: 3154: 3149: 3147:Turing machine 3144: 3139: 3134: 3129: 3124: 3119: 3118: 3117: 3112: 3107: 3102: 3097: 3087: 3085:Computable set 3082: 3077: 3072: 3067: 3061: 3059: 3053: 3052: 3050: 3049: 3044: 3039: 3034: 3029: 3024: 3019: 3014: 3013: 3012: 3007: 3002: 2992: 2987: 2982: 2980:Satisfiability 2977: 2972: 2967: 2966: 2965: 2955: 2954: 2953: 2943: 2942: 2941: 2936: 2931: 2926: 2921: 2911: 2910: 2909: 2904: 2897:Interpretation 2893: 2891: 2885: 2884: 2882: 2881: 2876: 2871: 2866: 2861: 2851: 2846: 2845: 2844: 2843: 2842: 2832: 2827: 2817: 2812: 2807: 2802: 2797: 2792: 2786: 2784: 2778: 2777: 2774: 2773: 2771: 2770: 2762: 2761: 2760: 2759: 2754: 2753: 2752: 2747: 2742: 2722: 2721: 2720: 2718:minimal axioms 2715: 2704: 2703: 2702: 2691: 2690: 2689: 2684: 2679: 2674: 2669: 2664: 2651: 2649: 2630: 2629: 2627: 2626: 2625: 2624: 2612: 2607: 2606: 2605: 2600: 2595: 2590: 2580: 2575: 2570: 2565: 2564: 2563: 2558: 2548: 2547: 2546: 2541: 2536: 2531: 2521: 2516: 2515: 2514: 2509: 2504: 2494: 2493: 2492: 2487: 2482: 2477: 2472: 2467: 2457: 2452: 2447: 2442: 2441: 2440: 2435: 2430: 2425: 2415: 2410: 2408:Formation rule 2405: 2400: 2399: 2398: 2393: 2383: 2382: 2381: 2371: 2366: 2361: 2356: 2350: 2344: 2327:Formal systems 2323: 2322: 2319: 2318: 2316: 2315: 2310: 2305: 2300: 2295: 2290: 2285: 2280: 2275: 2270: 2269: 2268: 2263: 2252: 2250: 2246: 2245: 2243: 2242: 2241: 2240: 2230: 2225: 2224: 2223: 2216:Large cardinal 2213: 2208: 2203: 2198: 2193: 2179: 2178: 2177: 2172: 2167: 2152: 2150: 2140: 2139: 2137: 2136: 2135: 2134: 2129: 2124: 2114: 2109: 2104: 2099: 2094: 2089: 2084: 2079: 2074: 2069: 2064: 2059: 2053: 2051: 2044: 2043: 2041: 2040: 2039: 2038: 2033: 2028: 2023: 2018: 2013: 2005: 2004: 2003: 1998: 1988: 1983: 1981:Extensionality 1978: 1976:Ordinal number 1973: 1963: 1958: 1957: 1956: 1945: 1939: 1933: 1932: 1929: 1928: 1926: 1925: 1920: 1915: 1910: 1905: 1900: 1895: 1894: 1893: 1883: 1882: 1881: 1868: 1866: 1860: 1859: 1857: 1856: 1855: 1854: 1849: 1844: 1834: 1829: 1824: 1819: 1814: 1809: 1803: 1801: 1795: 1794: 1792: 1791: 1786: 1781: 1776: 1771: 1766: 1761: 1760: 1759: 1749: 1744: 1739: 1734: 1729: 1724: 1718: 1716: 1707: 1701: 1700: 1698: 1697: 1692: 1687: 1682: 1677: 1672: 1660:Cantor's  1658: 1653: 1648: 1638: 1636: 1623: 1622: 1620: 1619: 1614: 1609: 1604: 1599: 1594: 1589: 1584: 1579: 1574: 1569: 1564: 1559: 1558: 1557: 1546: 1544: 1540: 1539: 1534: 1532: 1531: 1524: 1517: 1509: 1503: 1502: 1495: 1477: 1447: 1446: 1439: 1418: 1417: 1415: 1412: 1411: 1410: 1405: 1400: 1393: 1390: 1359:Turing machine 1350: 1347: 1306: 1301: 1297: 1276: 1273: 1269: 1237: 1182: 1179: 1178: 1177: 1157: 1154: 1151: 1148: 1145: 1142: 1139: 1136: 1113: 1101: 1098: 1095: 1092: 1089: 1086: 1081: 1077: 1073: 1069: 1065: 1062: 1059: 1056: 1053: 1049: 1045: 1025: 1014: 1011:Turing machine 990: 987: 984: 979: 975: 954: 951: 948: 945: 940: 936: 911: 908: 905: 902: 899: 879: 876: 873: 870: 867: 862: 858: 854: 851: 848: 845: 842: 839: 836: 816: 802: 795:productive set 791: 784: 777: 767: 764: 753: 746:computable set 740: 737: 734: 733: 701: 700: 699: 698: 691: 679: 676: 673: 670: 667: 664: 661: 658: 655: 652: 649: 646: 643: 640: 637: 634: 631: 628: 625: 622: 619: 616: 613: 610: 607: 604: 601: 595: 592: 589: 586: 583: 580: 577: 574: 571: 568: 565: 562: 559: 556: 553: 550: 547: 544: 541: 538: 535: 532: 475: 471: 470: 469: 468: 453: 438: 429: 428:Enumerability: 425: 424: 423: 422: 409: 404: 401: 398: 385: 373: 372: 369: 366: 363: 350: 348: 345: 344: 342: 337: 334: 331: 328: 325: 310: 292: 287: 283: 267: 254: 242: 239: 221:if there is a 210: 207: 192: 148:computable set 136: 135: 127: 120: 113: 91: 90: 26: 24: 14: 13: 10: 9: 6: 4: 3: 2: 3290: 3279: 3276: 3274: 3271: 3270: 3268: 3255: 3254: 3249: 3241: 3235: 3232: 3230: 3227: 3225: 3222: 3220: 3217: 3213: 3210: 3209: 3208: 3205: 3203: 3200: 3198: 3195: 3193: 3189: 3186: 3184: 3181: 3179: 3176: 3174: 3171: 3169: 3166: 3165: 3163: 3159: 3153: 3150: 3148: 3145: 3143: 3142:Recursive set 3140: 3138: 3135: 3133: 3130: 3128: 3125: 3123: 3120: 3116: 3113: 3111: 3108: 3106: 3103: 3101: 3098: 3096: 3093: 3092: 3091: 3088: 3086: 3083: 3081: 3078: 3076: 3073: 3071: 3068: 3066: 3063: 3062: 3060: 3058: 3054: 3048: 3045: 3043: 3040: 3038: 3035: 3033: 3030: 3028: 3025: 3023: 3020: 3018: 3015: 3011: 3008: 3006: 3003: 3001: 2998: 2997: 2996: 2993: 2991: 2988: 2986: 2983: 2981: 2978: 2976: 2973: 2971: 2968: 2964: 2961: 2960: 2959: 2956: 2952: 2951:of arithmetic 2949: 2948: 2947: 2944: 2940: 2937: 2935: 2932: 2930: 2927: 2925: 2922: 2920: 2917: 2916: 2915: 2912: 2908: 2905: 2903: 2900: 2899: 2898: 2895: 2894: 2892: 2890: 2886: 2880: 2877: 2875: 2872: 2870: 2867: 2865: 2862: 2859: 2858:from ZFC 2855: 2852: 2850: 2847: 2841: 2838: 2837: 2836: 2833: 2831: 2828: 2826: 2823: 2822: 2821: 2818: 2816: 2813: 2811: 2808: 2806: 2803: 2801: 2798: 2796: 2793: 2791: 2788: 2787: 2785: 2783: 2779: 2769: 2768: 2764: 2763: 2758: 2757:non-Euclidean 2755: 2751: 2748: 2746: 2743: 2741: 2740: 2736: 2735: 2733: 2730: 2729: 2727: 2723: 2719: 2716: 2714: 2711: 2710: 2709: 2705: 2701: 2698: 2697: 2696: 2692: 2688: 2685: 2683: 2680: 2678: 2675: 2673: 2670: 2668: 2665: 2663: 2660: 2659: 2657: 2653: 2652: 2650: 2645: 2639: 2634:Example  2631: 2623: 2618: 2617: 2616: 2613: 2611: 2608: 2604: 2601: 2599: 2596: 2594: 2591: 2589: 2586: 2585: 2584: 2581: 2579: 2576: 2574: 2571: 2569: 2566: 2562: 2559: 2557: 2554: 2553: 2552: 2549: 2545: 2542: 2540: 2537: 2535: 2532: 2530: 2527: 2526: 2525: 2522: 2520: 2517: 2513: 2510: 2508: 2505: 2503: 2500: 2499: 2498: 2495: 2491: 2488: 2486: 2483: 2481: 2478: 2476: 2473: 2471: 2468: 2466: 2463: 2462: 2461: 2458: 2456: 2453: 2451: 2448: 2446: 2443: 2439: 2436: 2434: 2431: 2429: 2426: 2424: 2421: 2420: 2419: 2416: 2414: 2411: 2409: 2406: 2404: 2401: 2397: 2394: 2392: 2391:by definition 2389: 2388: 2387: 2384: 2380: 2377: 2376: 2375: 2372: 2370: 2367: 2365: 2362: 2360: 2357: 2355: 2352: 2351: 2348: 2345: 2343: 2339: 2334: 2328: 2324: 2314: 2311: 2309: 2306: 2304: 2301: 2299: 2296: 2294: 2291: 2289: 2286: 2284: 2281: 2279: 2278:Kripke–Platek 2276: 2274: 2271: 2267: 2264: 2262: 2259: 2258: 2257: 2254: 2253: 2251: 2247: 2239: 2236: 2235: 2234: 2231: 2229: 2226: 2222: 2219: 2218: 2217: 2214: 2212: 2209: 2207: 2204: 2202: 2199: 2197: 2194: 2191: 2187: 2183: 2180: 2176: 2173: 2171: 2168: 2166: 2163: 2162: 2161: 2157: 2154: 2153: 2151: 2149: 2145: 2141: 2133: 2130: 2128: 2125: 2123: 2122:constructible 2120: 2119: 2118: 2115: 2113: 2110: 2108: 2105: 2103: 2100: 2098: 2095: 2093: 2090: 2088: 2085: 2083: 2080: 2078: 2075: 2073: 2070: 2068: 2065: 2063: 2060: 2058: 2055: 2054: 2052: 2050: 2045: 2037: 2034: 2032: 2029: 2027: 2024: 2022: 2019: 2017: 2014: 2012: 2009: 2008: 2006: 2002: 1999: 1997: 1994: 1993: 1992: 1989: 1987: 1984: 1982: 1979: 1977: 1974: 1972: 1968: 1964: 1962: 1959: 1955: 1952: 1951: 1950: 1947: 1946: 1943: 1940: 1938: 1934: 1924: 1921: 1919: 1916: 1914: 1911: 1909: 1906: 1904: 1901: 1899: 1896: 1892: 1889: 1888: 1887: 1884: 1880: 1875: 1874: 1873: 1870: 1869: 1867: 1865: 1861: 1853: 1850: 1848: 1845: 1843: 1840: 1839: 1838: 1835: 1833: 1830: 1828: 1825: 1823: 1820: 1818: 1815: 1813: 1810: 1808: 1805: 1804: 1802: 1800: 1799:Propositional 1796: 1790: 1787: 1785: 1782: 1780: 1777: 1775: 1772: 1770: 1767: 1765: 1762: 1758: 1755: 1754: 1753: 1750: 1748: 1745: 1743: 1740: 1738: 1735: 1733: 1730: 1728: 1727:Logical truth 1725: 1723: 1720: 1719: 1717: 1715: 1711: 1708: 1706: 1702: 1696: 1693: 1691: 1688: 1686: 1683: 1681: 1678: 1676: 1673: 1671: 1667: 1663: 1659: 1657: 1654: 1652: 1649: 1647: 1643: 1640: 1639: 1637: 1635: 1629: 1624: 1618: 1615: 1613: 1610: 1608: 1605: 1603: 1600: 1598: 1595: 1593: 1590: 1588: 1585: 1583: 1580: 1578: 1575: 1573: 1570: 1568: 1565: 1563: 1560: 1556: 1553: 1552: 1551: 1548: 1547: 1545: 1541: 1537: 1530: 1525: 1523: 1518: 1516: 1511: 1510: 1507: 1500: 1496: 1493: 1492:3-540-15299-7 1489: 1485: 1482: 1478: 1475: 1474:0-07-053522-1 1471: 1467: 1466:0-262-68052-1 1463: 1459: 1455: 1451: 1450: 1442: 1436: 1432: 1431: 1423: 1420: 1413: 1409: 1406: 1404: 1401: 1399: 1396: 1395: 1391: 1389: 1387: 1383: 1379: 1374: 1372: 1368: 1364: 1360: 1356: 1348: 1346: 1344: 1339: 1337: 1333: 1329: 1325: 1320: 1304: 1299: 1274: 1259: 1255: 1251: 1235: 1226: 1224: 1220: 1216: 1212: 1208: 1204: 1200: 1196: 1192: 1188: 1180: 1175: 1171: 1149: 1143: 1140: 1137: 1126: 1122: 1118: 1114: 1096: 1093: 1087: 1079: 1075: 1071: 1067: 1063: 1060: 1057: 1054: 1051: 1047: 1023: 1015: 1012: 1008: 1004: 985: 977: 973: 946: 938: 934: 925: 906: 903: 900: 868: 860: 856: 852: 846: 843: 840: 814: 807: 803: 800: 796: 792: 789: 788:creative sets 785: 782: 778: 775: 771: 768: 765: 762: 758: 754: 751: 747: 743: 742: 738: 727: 723: 722: 719: 717: 713: 708: 706: 696: 692: 677: 671: 668: 662: 659: 656: 653: 650: 647: 644: 641: 638: 635: 632: 629: 626: 623: 620: 617: 614: 611: 608: 602: 593: 590: 587: 584: 581: 578: 575: 572: 569: 566: 563: 560: 557: 554: 551: 548: 545: 536: 533: 530: 522: 518: 514: 510: 506: 502: 498: 494: 490: 486: 482: 478: 477: 476: 473: 472: 466: 462: 458: 454: 451: 447: 443: 439: 436: 432: 431: 430: 427: 426: 402: 399: 396: 367: 364: 361: 346: 340: 335: 329: 323: 315: 311: 308: 290: 285: 272: 268: 265: 261: 257: 256: 255: 252: 251: 250: 248: 240: 238: 236: 232: 228: 224: 220: 216: 208: 206: 180: 176: 172: 168: 163: 161: 157: 153: 149: 145: 141: 140:semidecidable 133: 126: 119: 112: 108: 104: 100: 96: 95: 94: 88: 84: 80: 79: 78: 76: 72: 68: 64: 60: 59:semidecidable 56: 52: 48: 44: 40: 33: 32:Countable set 19: 3244: 3074: 3042:Ultraproduct 2889:Model theory 2854:Independence 2790:Formal proof 2782:Proof theory 2765: 2738: 2695:real numbers 2667:second-order 2578:Substitution 2455:Metalanguage 2396:conservative 2369:Axiom schema 2313:Constructive 2283:Morse–Kelley 2249:Set theories 2228:Aleph number 2221:inaccessible 2127:Grothendieck 2011:intersection 1898:Higher-order 1886:Second-order 1832:Truth tables 1789:Venn diagram 1572:Formal proof 1498: 1480: 1453: 1429: 1422: 1381: 1377: 1375: 1370: 1362: 1352: 1340: 1335: 1331: 1323: 1321: 1253: 1249: 1227: 1214: 1210: 1206: 1202: 1198: 1194: 1190: 1186: 1184: 1173: 1169: 1124: 1120: 1116: 1002: 798: 749: 709: 702: 694: 520: 516: 512: 508: 504: 500: 496: 492: 488: 484: 480: 474:Diophantine: 464: 456: 445: 441: 434: 313: 270: 263: 259: 246: 244: 234: 230: 218: 214: 212: 164: 159: 155: 151: 143: 139: 137: 131: 130:, ... . If 124: 117: 110: 106: 102: 97:There is an 92: 86: 81:There is an 74: 70: 66: 62: 58: 54: 50: 42: 36: 3152:Type theory 3100:undecidable 3032:Truth value 2919:equivalence 2598:non-logical 2211:Enumeration 2201:Isomorphism 2148:cardinality 2132:Von Neumann 2097:Ultrafilter 2062:Uncountable 1996:equivalence 1913:Quantifiers 1903:Fixed-point 1872:First-order 1752:Consistency 1737:Proposition 1714:Traditional 1685:Lindström's 1675:Compactness 1617:Type theory 1562:Cardinality 1452:Rogers, H. 781:simple sets 705:dovetailing 316:such that: 229:is exactly 3267:Categories 2963:elementary 2656:arithmetic 2524:Quantifier 2502:functional 2374:Expression 2092:Transitive 2036:identities 2021:complement 1954:hereditary 1937:Set theory 1414:References 1328:computable 1258:complement 1248:is called 1181:Properties 1168:such that 965:indicates 49:is called 3234:Supertask 3137:Recursion 3095:decidable 2929:saturated 2907:of models 2830:deductive 2825:axiomatic 2745:Hilbert's 2732:Euclidean 2713:canonical 2636:axiomatic 2568:Signature 2497:Predicate 2386:Extension 2308:Ackermann 2233:Operation 2112:Universal 2102:Recursive 2077:Singleton 2072:Inhabited 2057:Countable 2047:Types of 2031:power set 2001:partition 1918:Predicate 1864:Predicate 1779:Syllogism 1769:Soundness 1742:Inference 1732:Tautology 1634:paradoxes 1458:MIT Press 1367:algorithm 1296:Π 1272:∖ 1156:⟩ 1135:⟨ 1076:ϕ 1072:∣ 1024:ϕ 974:ϕ 953:↓ 935:ϕ 910:⟩ 898:⟨ 875:↓ 857:ϕ 853:∣ 850:⟩ 838:⟨ 815:ϕ 543:∃ 540:⇔ 534:∈ 450:injective 400:∉ 365:∈ 282:Σ 83:algorithm 3219:Logicism 3212:timeline 3188:Concrete 3047:Validity 3017:T-schema 3010:Kripke's 3005:Tarski's 3000:semantic 2990:Strength 2939:submodel 2934:spectrum 2902:function 2750:Tarski's 2739:Elements 2726:geometry 2682:Robinson 2603:variable 2588:function 2561:spectrum 2551:Sentence 2507:variable 2450:Language 2403:Relation 2364:Automata 2354:Alphabet 2338:language 2192:-jection 2170:codomain 2156:Function 2117:Universe 2087:Infinite 1991:Relation 1774:Validity 1764:Argument 1662:theorem, 1392:See also 1223:preimage 1068:⟩ 1048:⟨ 804:Given a 739:Examples 455:The set 440:The set 433:The set 269:The set 258:The set 71:provable 67:listable 41:, a set 3161:Related 2958:Diagram 2856: ( 2835:Hilbert 2820:Systems 2815:Theorem 2693:of the 2638:systems 2418:Formula 2413:Grammar 2329: ( 2273:General 1986:Forcing 1971:Element 1891:Monadic 1666:paradox 1607:Theorem 1543:General 1349:Remarks 1256:if its 1254:co-c.e. 922:is the 890:(where 179:lattice 2924:finite 2687:Skolem 2640:  2615:Theory 2583:Symbol 2573:String 2556:atomic 2433:ground 2428:closed 2423:atomic 2379:ground 2342:syntax 2238:binary 2165:domain 2082:Finite 1847:finite 1705:Logics 1664:  1612:Theory 1490:  1472:  1464:  1437:  1378:domain 1322:A set 1228:A set 1013:halts. 744:Every 597:  394:  382:  359:  227:domain 225:whose 213:A set 169:, the 144:decide 2914:Model 2662:Peano 2519:Proof 2359:Arity 2288:Naive 2175:image 2107:Fuzzy 2067:Empty 2016:union 1961:Class 1602:Model 1592:Lemma 1550:Axiom 1382:range 3037:Type 2840:list 2644:list 2621:list 2610:Term 2544:rank 2438:open 2332:list 2144:Maps 2049:sets 1908:Free 1878:list 1628:list 1555:list 1488:ISBN 1470:ISBN 1462:ISBN 1435:ISBN 1209:and 1189:and 926:and 793:Any 786:The 779:The 160:r.e. 158:and 156:c.e. 77:if: 2724:of 2706:of 2654:of 2186:Sur 2160:Map 1967:Ur- 1949:Set 1326:is 1252:or 1185:If 799:not 797:is 750:not 273:is 165:In 109:: 73:or 45:of 37:In 3269:: 3110:NP 2734:: 2728:: 2658:: 2335:), 2190:Bi 2182:In 1468:; 1460:. 1456:, 1213:× 1205:âˆȘ 1201:, 1197:∩ 755:A 707:. 519:, 515:, 511:, 507:, 503:, 499:, 495:, 491:, 487:, 389:if 354:if 309:). 237:. 205:. 175:RE 123:, 116:, 69:, 65:, 61:, 57:, 53:, 3190:/ 3105:P 2860:) 2646:) 2642:( 2539:∀ 2534:! 2529:∃ 2490:= 2485:↔ 2480:→ 2475:∧ 2470:√ 2465:ÂŹ 2188:/ 2184:/ 2158:/ 1969:) 1965:( 1852:∞ 1842:3 1630:) 1528:e 1521:t 1514:v 1494:. 1476:. 1443:. 1371:S 1363:S 1336:A 1332:A 1324:A 1305:0 1300:1 1275:T 1268:N 1236:T 1215:B 1211:A 1207:B 1203:A 1199:B 1195:A 1191:B 1187:A 1174:x 1172:( 1170:f 1153:) 1150:x 1147:( 1144:f 1141:, 1138:x 1125:f 1121:f 1117:f 1100:} 1097:z 1094:= 1091:) 1088:y 1085:( 1080:x 1064:z 1061:, 1058:y 1055:, 1052:x 1044:{ 1003:x 989:) 986:x 983:( 978:i 950:) 947:x 944:( 939:i 907:x 904:, 901:i 878:} 872:) 869:x 866:( 861:i 847:x 844:, 841:i 835:{ 763:. 695:S 678:. 675:) 672:0 669:= 666:) 663:i 660:, 657:h 654:, 651:g 648:, 645:f 642:, 639:e 636:, 633:d 630:, 627:c 624:, 621:b 618:, 615:a 612:, 609:x 606:( 603:p 600:( 594:i 591:, 588:h 585:, 582:g 579:, 576:f 573:, 570:e 567:, 564:d 561:, 558:c 555:, 552:b 549:, 546:a 537:S 531:x 521:i 517:h 513:g 509:f 505:e 501:d 497:c 493:b 489:a 485:x 481:p 465:S 457:S 452:. 446:S 442:S 435:S 403:S 397:x 368:S 362:x 347:1 341:{ 336:= 333:) 330:x 327:( 324:f 314:f 291:0 286:1 271:S 264:S 260:S 247:S 235:S 231:S 215:S 191:E 132:S 128:3 125:s 121:2 118:s 114:1 111:s 107:S 103:S 89:. 87:S 43:S 34:. 20:)

Index

Recursively enumerable set
Countable set
computability theory
natural numbers
algorithm
algorithm that enumerates
computable set
computational complexity theory
complexity class
RE
lattice
partial computable function
domain
arithmetical hierarchy
injective
primitive recursive function
dovetailing
Yuri Matiyasevich
Hilbert's Tenth Problem

computable set
recursively enumerable language
formal language
Matiyasevich's theorem
Diophantine set
simple sets
creative sets
productive set
Gödel numbering
Cantor pairing function

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