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Fixed-point logic

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The fixed-point operations that we defined so far iterate the inductive definitions of the predicates mentioned in the formula indefinitely, until a fixed point is reached. In implementations, it may be necessary to bound the number of iterations to limit the computation time. The resulting operators
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This inflationary fixed-point agrees with the least-fixed point where the latter is defined. Although at first glance it seems as if inflationary fixed-point logic should be more expressive than least fixed-point logic since it supports a wider range of fixed-point arguments, in fact, every
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While all the fixed-point operators introduced so far iterated only on the definition of a single predicate, many computer programs are more naturally thought of as iterating over several predicates simultaneously. By either increasing the
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of the fixed-point operators or by nesting them, every simultaneous least, inflationary or partial fixed-point can in fact be expressed using the corresponding single-iteration constructions discussed above.
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Since the iterated predicates involved in calculating the partial fixed point are not in general monotone, the fixed-point may not always exist. FO(LFP,X),
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Yuri Gurevich and Saharon Shelah, Fixed-pointed extension of first order logic, Annals of Pure and Applied Logic 32 (1986) 265--280.
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are extensions of classical predicate logic that have been introduced to express recursion. Their development has been motivated by
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are also of interest from a theoretical point of view since they can also be used to characterise complexity classes.
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The expressivity of least-fixed point logic coincides exactly with the expressivity of the database querying language
5135: 3769: 3460: 3351: 4477: 1128: 5232: 4976: 3801: 487: 5554: 4537: 4230: 2438: 3971: 987:, showing that, on ordered structures, Datalog can express exactly those queries executable in polynomial time. 5493: 5195: 4958: 4953: 4778: 4199: 3883: 3619: 1941:) is defined as FO(TC,X) where the transitive closure operator is deterministic. This means that when we apply 1929:. This characterisation is a crucial part of Immerman's proof that NL is closed under complement (NL = co-NL). 1245:
using first-order connectives and predicates, second-order variables as well as a transitive closure operator
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Another way to ensure the monotonicity of the fixed-point construction is by only adding new tuples to
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Proceedings of the 6th ACM SIGACT-SIGPLAN Symposium on Principles of Programming Languages - POPL '79
1737: 813:, is the set of formulas in FO(PFP,X) where the partial fixed point is taken only over such formulas 3966: 3527: 3245: 3187: 3121: 3045: 2986: 2909: 2355: 2252: 433: 5564: 5559: 5351: 5281: 4820: 4672: 4655: 4378: 3858: 2482: 2403: 5183: 5160: 5121: 5007: 4948: 4594: 4514: 4358: 4302: 3915: 32: 1997: 1874: 1558: 1529: 1500: 1471: 1442: 1413: 1384: 1355: 864: 281: 252: 223: 194: 108: 5473: 5200: 5178: 5145: 5038: 4884: 4869: 4842: 4793: 4677: 4612: 4437: 4403: 4398: 4272: 4103: 4080: 3522: 3323: 2665: 732: 43: 2739: 2719: 828: 5403: 5256: 5048: 4766: 4502: 4408: 4267: 4252: 4133: 4108: 2763: 1704: 1594: 687: 598: 561: 3517:
Vardi, Moshe Y. (1982). "The complexity of relational query languages (Extended Abstract)".
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is a (class of) functions from integers to integers, and for different classes of functions
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Rather than allow induction over arbitrary predicates, transitive closure logic allows only
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It has been proven that on ordered finite structures, a property is expressible in FO(PFP,
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Proceedings of the fourteenth annual ACM symposium on Theory of computing - STOC '82
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Proceedings of the fifteenth annual ACM symposium on Theory of computing - STOC '83
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to be the FO-formulae with an iteration operator whose exponent is in the class
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s, so with a polynomial-space counter we can check if there is a loop or not.
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suggested fixed-point logic as an expressive database query language.
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in 1974, and it was introduced to computer scientists in 1979, when
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Over ordered structures, FO characterises the complexity class
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Over ordered structures, FO characterises the complexity class
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at every stage of iteration, without removing tuples for which
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iterations. The Immerman-Vardi theorem, shown independently by
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Due to monotonicity, we only add vectors to the truth table of
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Least fixed-point logic was first studied systematically by
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possible vectors we will always find a fixed point before
1932: 3645:"Nondeterministic Space is Closed under Complementation" 3606:. New York, New York, USA: ACM Press. pp. 347–354. 1410:
are tuples of pairwise distinct first-order variables,
595:). Then, either there is a fixed point, or the list of 3248: 3190: 3124: 3093: 3048: 2989: 2957: 2912: 2880: 2841: 2812: 2766: 2742: 2722: 2695: 2668: 2564: 2520: 2485: 2441: 2406: 2358: 2329: 2300: 2255: 2132: 2087: 2038: 2000: 1947: 1877: 1818: 1792: 1740: 1707: 1639: 1597: 1561: 1532: 1503: 1474: 1445: 1416: 1387: 1358: 1271: 1251: 1131: 1086: 1041: 1021: 1001: 943: 916: 867: 831: 769: 735: 690: 636: 601: 564: 490: 436: 390: 340: 313: 284: 255: 226: 197: 177: 111: 91: 3332:
Studies in Logic and the Foundations of Mathematics
2835:time. One should pay attention that here there are 3486:"Relational queries computable in polynomial time" 3293: 3228: 3174: 3108: 3079: 3030: 2972: 2943: 2895: 2862: 2827: 2794: 2748: 2728: 2708: 2681: 2654: 2550: 2506: 2471: 2427: 2389: 2344: 2315: 2286: 2222: 2118: 2069: 2021: 1978: 1898: 1859: 1804: 1778: 1726: 1689: 1621: 1576: 1547: 1518: 1489: 1460: 1431: 1402: 1373: 1344: 1257: 1188: 1117: 1072: 1027: 1007: 956: 929: 895: 853: 782: 755: 709: 676: 620: 583: 546: 476: 422: 352: 319: 299: 270: 241: 212: 183: 163: 97: 2070:{\displaystyle \operatorname {DTC} (\phi _{u,v})} 1979:{\displaystyle \operatorname {DTC} (\phi _{u,v})} 1118:{\displaystyle \operatorname {PFP} (\psi _{P,x})} 1073:{\displaystyle \operatorname {IFP} (\phi _{P,x})} 990: 5546: 2119:{\displaystyle \operatorname {TC} (\psi _{u,v})} 1690:{\displaystyle {\mathsf {TC}}(\phi _{u,v})(x,y)} 721:if there is a fixed point, else as false. Since 3383:. New York, New York, USA: ACM Press: 110–119. 3730: 3438: 2874:variables and each of those variable are used 1189:{\displaystyle \psi (P,x)=\phi (P,x)\vee P(x)} 684:is defined as the value of the fixed point of 3802: 3731:Ebbinghaus, Heinz-Dieter; Flum, Jörg (1999). 3328:"Elementary Induction on Abstract Structures" 3600:"Languages which capture complexity classes" 3521:. New York, NY, USA: ACM. pp. 137–146. 2802:the iteration operator, which is defined as 2352:we will obtain different complexity classes 547:{\displaystyle P_{i}(x)=\varphi (P_{i-1},x)} 57: 3447:. IEEE Comput. Soc. Press. pp. 71–79. 3375:Aho, Alfred V.; Ullman, Jeffrey D. (1979). 3322: 3305:. It is also another way to write FO(PFP). 2472:{\displaystyle (\forall x(P\Rightarrow Q))} 2249:We will define first-order with iteration, 1225: 3994: 3809: 3795: 3377:"Universality of data retrieval languages" 3240:. It is also another way to write FO(IFP). 2980:, and we obtain the following equalities: 817:that only contain positive occurrences of 804: 591:substituted for the second-order variable 85:as well as a partial fixed point operator 3526: 3501: 3388: 3374: 2760:is a quantifiers block then we will call 1211: 3642: 3597: 3483: 384:as variables. We can iteratively define 5547: 3816: 3254: 3251: 3196: 3193: 3130: 3127: 3054: 3051: 2995: 2992: 2918: 2915: 2689:s are quantifier-free FO-formulae and 2551:{\displaystyle (\exists x(P\wedge Q))} 2364: 2361: 2261: 2258: 1933:Deterministic transitive closure logic 1645: 1642: 79:first-order connectives and predicates 3790: 3593: 3591: 3516: 1241:) is the set of formulas formed from 1035:no longer holds. Formally, we define 73:) is the set of formulas formed from 3757: 1860:{\displaystyle \phi (z_{i},z_{i+1})} 1345:{\displaystyle {\vec {s}}{\vec {t}}} 368:be a second-order variable of arity 249:a tuple of terms and the lengths of 98:{\displaystyle \operatorname {PFP} } 1871:is a formula written in FO(TC) and 1468:tuples of terms and the lengths of 1258:{\displaystyle \operatorname {TC} } 13: 3588: 2870:quantifiers in the list, but only 2743: 2723: 2524: 2489: 2445: 2410: 2196: 2175: 1265:used to form formulas of the form 220:a tuple of first-order variables, 105:used to form formulas of the form 14: 5576: 3585:Ebbinghaus and Flum, pp. 179, 193 3439:Abiteboul, S.; Vianu, V. (1989). 1204:)-formula is equivalent to an FO( 5528: 423:{\displaystyle (P_{i})_{i\in N}} 3711: 3702: 3693: 3684: 3675: 3636: 3579: 3570: 2400:In this section we will write 1779:{\displaystyle z_{1}=x,z_{n}=y} 376:be an FO(PFP,X) function using 3561: 3510: 3477: 3432: 3423: 3414: 3405: 3368: 3316: 3294:{\displaystyle {\mathsf {FO}}} 3288: 3281: 3275: 3259: 3229:{\displaystyle {\mathsf {FO}}} 3223: 3218: 3212: 3201: 3175:{\displaystyle {\mathsf {FO}}} 3169: 3164: 3158: 3151: 3138: 3135: 3103: 3097: 3080:{\displaystyle {\mathsf {FO}}} 3074: 3071: 3065: 3059: 3031:{\displaystyle {\mathsf {FO}}} 3025: 3016: 3003: 3000: 2967: 2961: 2944:{\displaystyle {\mathsf {FO}}} 2938: 2935: 2929: 2923: 2890: 2884: 2857: 2851: 2822: 2816: 2787: 2781: 2774: 2767: 2649: 2613: 2601: 2565: 2545: 2542: 2530: 2521: 2498: 2486: 2466: 2463: 2457: 2451: 2442: 2419: 2407: 2390:{\displaystyle {\mathsf {FO}}} 2384: 2381: 2375: 2369: 2339: 2333: 2310: 2304: 2287:{\displaystyle {\mathsf {FO}}} 2281: 2278: 2272: 2266: 2217: 2214: 2202: 2181: 2169: 2157: 2148: 2136: 2113: 2094: 2064: 2045: 2016: 2004: 1973: 1954: 1893: 1881: 1854: 1822: 1721: 1708: 1684: 1672: 1669: 1650: 1587:TC is defined as follows: Let 1568: 1539: 1510: 1481: 1452: 1423: 1394: 1365: 1336: 1324: 1315: 1301: 1286: 1272: 1183: 1177: 1168: 1156: 1147: 1135: 1112: 1093: 1067: 1048: 991:Inflationary fixed-point logic 890: 884: 848: 842: 704: 691: 671: 668: 662: 637: 615: 602: 541: 516: 507: 501: 477:{\displaystyle P_{0}(x)=false} 453: 447: 405: 391: 291: 262: 233: 204: 155: 146: 126: 112: 1: 5489:History of mathematical logic 3724: 3503:10.1016/s0019-9958(86)80029-8 3344:10.1016/s0049-237x(08)x7092-2 2507:{\displaystyle (\exists xP)Q} 2428:{\displaystyle (\forall xP)Q} 2240: 29:descriptive complexity theory 16:Concept in mathematical logic 5414:Primitive recursive function 797:) if and only if it lies in 191:is a second-order variable, 7: 3567:Ebbinghaus and Flum, p. 242 3420:Ebbinghaus and Flum, p. 121 3411:Ebbinghaus and Flum, p. 121 1990:, there exists at most one 980:on all ordered structures. 910:, and since there are only 307:coincide with the arity of 10: 5581: 4478:Schröder–Bernstein theorem 4205:Monadic predicate calculus 3864:Foundations of mathematics 3087:is FO-uniform AC of depth 2022:{\displaystyle \phi (u,v)} 1899:{\displaystyle \phi (x,y)} 1591:be a positive integer and 1577:{\displaystyle {\vec {t}}} 1548:{\displaystyle {\vec {s}}} 1519:{\displaystyle {\vec {y}}} 1490:{\displaystyle {\vec {x}}} 1461:{\displaystyle {\vec {s}}} 1432:{\displaystyle {\vec {t}}} 1403:{\displaystyle {\vec {y}}} 1374:{\displaystyle {\vec {x}}} 1234:to be expressed directly. 896:{\displaystyle P_{i+1}(x)} 725:s are properties of arity 300:{\displaystyle {\vec {t}}} 271:{\displaystyle {\vec {x}}} 242:{\displaystyle {\vec {t}}} 213:{\displaystyle {\vec {x}}} 164:{\displaystyle {\vec {t}}} 31:and their relationship to 5524: 5511:Philosophy of mathematics 5460:Automated theorem proving 5442: 5337: 5169: 5062: 4914: 4631: 4607: 4585:Von Neumann–Bernays–Gödel 4530: 4424: 4328: 4226: 4217: 4144: 4079: 3985: 3907: 3824: 3741:10.1007/978-3-662-03182-7 3649:SIAM Journal on Computing 2682:{\displaystyle \phi _{i}} 1906:means that the variables 756:{\displaystyle 2^{n^{k}}} 58:Partial fixed-point logic 3309: 2749:{\displaystyle \exists } 2729:{\displaystyle \forall } 1226:Transitive closure logic 854:{\displaystyle P_{i}(x)} 33:database query languages 5161:Self-verifying theories 4982:Tarski's axiomatization 3933:Tarski's undefinability 3928:incompleteness theorems 3758:Neil, Immerman (1999). 3643:Immerman, Neil (1988). 3598:Immerman, Neil (1983). 3490:Information and Control 3484:Immerman, Neil (1986). 3453:10.1109/lics.1989.39160 3324:Moschovakis, Yiannis N. 3038:is equal to FO-uniform 2795:{\displaystyle ^{t(n)}} 1986:, we know that for all 1727:{\displaystyle (z_{i})} 1697:is true if there exist 1622:{\displaystyle u,v,x,y} 811:least fixed-point logic 805:Least fixed-point logic 710:{\displaystyle (P_{i})} 621:{\displaystyle (P_{i})} 584:{\displaystyle P_{i-1}} 5555:Descriptive complexity 5535:Mathematics portal 5146:Proof of impossibility 4794:propositional variable 4104:Propositional calculus 3761:Descriptive complexity 3295: 3230: 3176: 3110: 3081: 3032: 2974: 2945: 2897: 2864: 2863:{\displaystyle k*t(n)} 2829: 2796: 2750: 2730: 2710: 2683: 2656: 2552: 2508: 2473: 2429: 2391: 2346: 2317: 2288: 2224: 2120: 2071: 2023: 1980: 1900: 1861: 1806: 1805:{\displaystyle i<n} 1780: 1728: 1691: 1623: 1578: 1549: 1520: 1491: 1462: 1433: 1404: 1375: 1346: 1259: 1212:Simultaneous induction 1190: 1119: 1074: 1029: 1009: 958: 931: 897: 855: 784: 757: 711: 678: 622: 585: 548: 478: 424: 354: 321: 301: 272: 243: 214: 185: 165: 99: 83:second-order variables 44:Yiannis N. Moschovakis 5404:Kolmogorov complexity 5357:Computably enumerable 5257:Model complete theory 5049:Principia Mathematica 4109:Propositional formula 3938:Banach–Tarski paradox 3717:Immerman 1999, p. 161 3612:10.1145/800061.808765 3537:10.1145/800070.802186 3429:Immerman 1999, p. 161 3390:10.1145/567752.567763 3296: 3231: 3177: 3111: 3082: 3033: 2975: 2946: 2898: 2865: 2830: 2797: 2751: 2731: 2711: 2709:{\displaystyle Q_{i}} 2684: 2657: 2553: 2509: 2474: 2430: 2392: 2347: 2318: 2289: 2225: 2121: 2072: 2024: 1981: 1901: 1862: 1807: 1781: 1729: 1701:vectors of variables 1692: 1624: 1579: 1550: 1521: 1492: 1463: 1434: 1405: 1376: 1347: 1260: 1191: 1120: 1075: 1030: 1010: 959: 957:{\displaystyle n^{k}} 932: 930:{\displaystyle n^{k}} 898: 856: 785: 783:{\displaystyle P_{i}} 758: 712: 679: 623: 586: 549: 479: 425: 355: 322: 302: 273: 244: 215: 186: 166: 100: 5352:Church–Turing thesis 5339:Computability theory 4548:continuum hypothesis 4066:Square of opposition 3924:Gödel's completeness 3708:Immerman 1999, p. 58 3699:Immerman 1999, p. 84 3690:Immerman 1999, p. 82 3681:Immerman 1999, p. 63 3246: 3188: 3122: 3109:{\displaystyle t(n)} 3091: 3046: 2987: 2973:{\displaystyle t(n)} 2955: 2910: 2896:{\displaystyle t(n)} 2878: 2839: 2828:{\displaystyle t(n)} 2810: 2764: 2740: 2720: 2693: 2666: 2562: 2518: 2483: 2439: 2404: 2356: 2345:{\displaystyle t(n)} 2327: 2316:{\displaystyle t(n)} 2298: 2253: 2130: 2085: 2036: 2032:We can suppose that 1998: 1945: 1875: 1816: 1790: 1738: 1705: 1637: 1595: 1559: 1530: 1501: 1472: 1443: 1414: 1385: 1356: 1269: 1249: 1129: 1084: 1039: 1019: 999: 972:, shows that FO(LFP, 941: 914: 865: 829: 767: 733: 729:, there are at most 688: 634: 599: 562: 488: 434: 388: 338: 311: 282: 253: 224: 195: 175: 109: 89: 64:relational signature 5506:Mathematical object 5397:P versus NP problem 5362:Computable function 5156:Reverse mathematics 5082:Logical consequence 4959:primitive recursive 4954:elementary function 4727:Free/bound variable 4580:Tarski–Grothendieck 4099:Logical connectives 4029:Logical equivalence 3879:Logical consequence 3733:Finite Model Theory 1232:transitive closures 353:{\displaystyle x,y} 35:, in particular to 5304:Transfer principle 5267:Semantics of logic 5252:Categorical theory 5228:Non-standard model 4742:Logical connective 3869:Information theory 3818:Mathematical logic 3291: 3226: 3172: 3106: 3077: 3028: 2970: 2941: 2906:We can now define 2893: 2860: 2825: 2792: 2746: 2726: 2706: 2679: 2652: 2548: 2504: 2469: 2425: 2387: 2342: 2313: 2284: 2220: 2116: 2067: 2019: 1976: 1896: 1857: 1802: 1776: 1724: 1687: 1619: 1574: 1545: 1516: 1487: 1458: 1429: 1400: 1371: 1342: 1255: 1186: 1115: 1070: 1025: 1005: 954: 927: 893: 851: 780: 753: 707: 674: 618: 581: 544: 474: 420: 350: 317: 297: 268: 239: 210: 181: 161: 95: 25:fixed-point logics 21:mathematical logic 5542: 5541: 5474:Abstract category 5277:Theories of truth 5087:Rule of inference 5077:Natural deduction 5058: 5057: 4603: 4602: 4308:Cartesian product 4213: 4212: 4119:Many-valued logic 4094:Boolean functions 3977:Russell's paradox 3952:diagonal argument 3849:First-order logic 3750:978-3-662-03184-1 1571: 1542: 1513: 1484: 1455: 1426: 1397: 1368: 1339: 1327: 1304: 1289: 1028:{\displaystyle P} 1008:{\displaystyle P} 320:{\displaystyle P} 294: 265: 236: 207: 184:{\displaystyle P} 158: 129: 5572: 5533: 5532: 5484:History of logic 5479:Category of sets 5372:Decision problem 5151:Ordinal analysis 5092:Sequent calculus 4990:Boolean algebras 4930: 4929: 4904: 4875:logical/constant 4629: 4628: 4615: 4538:Zermelo–Fraenkel 4289:Set operations: 4224: 4223: 4161: 3992: 3991: 3972:Löwenheim–Skolem 3859:Formal semantics 3811: 3804: 3797: 3788: 3787: 3783: 3754: 3718: 3715: 3709: 3706: 3700: 3697: 3691: 3688: 3682: 3679: 3673: 3672: 3640: 3634: 3633: 3595: 3586: 3583: 3577: 3574: 3568: 3565: 3559: 3558: 3530: 3514: 3508: 3507: 3505: 3481: 3475: 3474: 3436: 3430: 3427: 3421: 3418: 3412: 3409: 3403: 3402: 3392: 3372: 3366: 3365: 3320: 3300: 3298: 3297: 3292: 3287: 3286: 3285: 3284: 3258: 3257: 3235: 3233: 3232: 3227: 3222: 3221: 3200: 3199: 3181: 3179: 3178: 3173: 3168: 3167: 3134: 3133: 3115: 3113: 3112: 3107: 3086: 3084: 3083: 3078: 3058: 3057: 3037: 3035: 3034: 3029: 3024: 3023: 2999: 2998: 2979: 2977: 2976: 2971: 2950: 2948: 2947: 2942: 2922: 2921: 2902: 2900: 2899: 2894: 2873: 2869: 2867: 2866: 2861: 2834: 2832: 2831: 2826: 2805: 2801: 2799: 2798: 2793: 2791: 2790: 2759: 2755: 2753: 2752: 2747: 2735: 2733: 2732: 2727: 2715: 2713: 2712: 2707: 2705: 2704: 2688: 2686: 2685: 2680: 2678: 2677: 2661: 2659: 2658: 2653: 2648: 2647: 2635: 2634: 2625: 2624: 2600: 2599: 2587: 2586: 2577: 2576: 2557: 2555: 2554: 2549: 2513: 2511: 2510: 2505: 2478: 2476: 2475: 2470: 2434: 2432: 2431: 2426: 2396: 2394: 2393: 2388: 2368: 2367: 2351: 2349: 2348: 2343: 2322: 2320: 2319: 2314: 2293: 2291: 2290: 2285: 2265: 2264: 2229: 2227: 2226: 2221: 2125: 2123: 2122: 2117: 2112: 2111: 2076: 2074: 2073: 2068: 2063: 2062: 2028: 2026: 2025: 2020: 1993: 1989: 1985: 1983: 1982: 1977: 1972: 1971: 1921: 1917: 1914:are replaced by 1913: 1909: 1905: 1903: 1902: 1897: 1870: 1866: 1864: 1863: 1858: 1853: 1852: 1834: 1833: 1811: 1809: 1808: 1803: 1785: 1783: 1782: 1777: 1769: 1768: 1750: 1749: 1733: 1731: 1730: 1725: 1720: 1719: 1700: 1696: 1694: 1693: 1688: 1668: 1667: 1649: 1648: 1633:variables. Then 1632: 1628: 1626: 1625: 1620: 1590: 1583: 1581: 1580: 1575: 1573: 1572: 1564: 1554: 1552: 1551: 1546: 1544: 1543: 1535: 1525: 1523: 1522: 1517: 1515: 1514: 1506: 1496: 1494: 1493: 1488: 1486: 1485: 1477: 1467: 1465: 1464: 1459: 1457: 1456: 1448: 1438: 1436: 1435: 1430: 1428: 1427: 1419: 1409: 1407: 1406: 1401: 1399: 1398: 1390: 1380: 1378: 1377: 1372: 1370: 1369: 1361: 1351: 1349: 1348: 1343: 1341: 1340: 1332: 1329: 1328: 1320: 1308: 1307: 1306: 1305: 1297: 1291: 1290: 1282: 1264: 1262: 1261: 1256: 1195: 1193: 1192: 1187: 1124: 1122: 1121: 1116: 1111: 1110: 1079: 1077: 1076: 1071: 1066: 1065: 1034: 1032: 1031: 1026: 1014: 1012: 1011: 1006: 976:) characterises 963: 961: 960: 955: 953: 952: 936: 934: 933: 928: 926: 925: 909: 902: 900: 899: 894: 883: 882: 860: 858: 857: 852: 841: 840: 824: 820: 816: 789: 787: 786: 781: 779: 778: 762: 760: 759: 754: 752: 751: 750: 749: 728: 724: 720: 716: 714: 713: 708: 703: 702: 683: 681: 680: 677:{\displaystyle } 675: 655: 654: 627: 625: 624: 619: 614: 613: 594: 590: 588: 587: 582: 580: 579: 557: 553: 551: 550: 545: 534: 533: 500: 499: 483: 481: 480: 475: 446: 445: 429: 427: 426: 421: 419: 418: 403: 402: 383: 379: 375: 371: 367: 363: 359: 357: 356: 351: 333: 326: 324: 323: 318: 306: 304: 303: 298: 296: 295: 287: 277: 275: 274: 269: 267: 266: 258: 248: 246: 245: 240: 238: 237: 229: 219: 217: 216: 211: 209: 208: 200: 190: 188: 187: 182: 170: 168: 167: 162: 160: 159: 151: 139: 138: 131: 130: 122: 104: 102: 101: 96: 5580: 5579: 5575: 5574: 5573: 5571: 5570: 5569: 5565:Predicate logic 5560:Database theory 5545: 5544: 5543: 5538: 5527: 5520: 5465:Category theory 5455:Algebraic logic 5438: 5409:Lambda calculus 5347:Church encoding 5333: 5309:Truth predicate 5165: 5131:Complete theory 5054: 4923: 4919: 4915: 4910: 4902: 4622: and  4618: 4613: 4599: 4575:New Foundations 4543:axiom of choice 4526: 4488:Gödel numbering 4428: and  4420: 4324: 4209: 4159: 4140: 4089:Boolean algebra 4075: 4039:Equiconsistency 4004:Classical logic 3981: 3962:Halting problem 3950: and  3926: and  3914: and  3913: 3908:Theorems ( 3903: 3820: 3815: 3772: 3751: 3727: 3722: 3721: 3716: 3712: 3707: 3703: 3698: 3694: 3689: 3685: 3680: 3676: 3661:10.1137/0217058 3641: 3637: 3622: 3596: 3589: 3584: 3580: 3575: 3571: 3566: 3562: 3547: 3528:10.1.1.331.6045 3515: 3511: 3496:(1–3): 86–104. 3482: 3478: 3463: 3437: 3433: 3428: 3424: 3419: 3415: 3410: 3406: 3373: 3369: 3354: 3321: 3317: 3312: 3271: 3267: 3266: 3262: 3250: 3249: 3247: 3244: 3243: 3208: 3204: 3192: 3191: 3189: 3186: 3185: 3182:is equal to NC. 3154: 3150: 3126: 3125: 3123: 3120: 3119: 3092: 3089: 3088: 3050: 3049: 3047: 3044: 3043: 3019: 3015: 2991: 2990: 2988: 2985: 2984: 2956: 2953: 2952: 2914: 2913: 2911: 2908: 2907: 2879: 2876: 2875: 2871: 2840: 2837: 2836: 2811: 2808: 2807: 2803: 2777: 2773: 2765: 2762: 2761: 2757: 2741: 2738: 2737: 2721: 2718: 2717: 2700: 2696: 2694: 2691: 2690: 2673: 2669: 2667: 2664: 2663: 2643: 2639: 2630: 2626: 2620: 2616: 2595: 2591: 2582: 2578: 2572: 2568: 2563: 2560: 2559: 2519: 2516: 2515: 2484: 2481: 2480: 2440: 2437: 2436: 2405: 2402: 2401: 2360: 2359: 2357: 2354: 2353: 2328: 2325: 2324: 2299: 2296: 2295: 2257: 2256: 2254: 2251: 2250: 2243: 2131: 2128: 2127: 2101: 2097: 2086: 2083: 2082: 2079:syntactic sugar 2052: 2048: 2037: 2034: 2033: 1999: 1996: 1995: 1991: 1987: 1961: 1957: 1946: 1943: 1942: 1935: 1919: 1915: 1911: 1907: 1876: 1873: 1872: 1868: 1867:is true. Here, 1842: 1838: 1829: 1825: 1817: 1814: 1813: 1791: 1788: 1787: 1764: 1760: 1745: 1741: 1739: 1736: 1735: 1715: 1711: 1706: 1703: 1702: 1698: 1657: 1653: 1641: 1640: 1638: 1635: 1634: 1630: 1596: 1593: 1592: 1588: 1563: 1562: 1560: 1557: 1556: 1534: 1533: 1531: 1528: 1527: 1505: 1504: 1502: 1499: 1498: 1476: 1475: 1473: 1470: 1469: 1447: 1446: 1444: 1441: 1440: 1418: 1417: 1415: 1412: 1411: 1389: 1388: 1386: 1383: 1382: 1360: 1359: 1357: 1354: 1353: 1331: 1330: 1319: 1318: 1296: 1295: 1281: 1280: 1279: 1275: 1270: 1267: 1266: 1250: 1247: 1246: 1228: 1214: 1130: 1127: 1126: 1100: 1096: 1085: 1082: 1081: 1055: 1051: 1040: 1037: 1036: 1020: 1017: 1016: 1000: 997: 996: 993: 948: 944: 942: 939: 938: 921: 917: 915: 912: 911: 907: 872: 868: 866: 863: 862: 861:always implies 836: 832: 830: 827: 826: 822: 818: 814: 807: 774: 770: 768: 765: 764: 763:values for the 745: 741: 740: 736: 734: 731: 730: 726: 722: 718: 698: 694: 689: 686: 685: 644: 640: 635: 632: 631: 609: 605: 600: 597: 596: 592: 569: 565: 563: 560: 559: 555: 523: 519: 495: 491: 489: 486: 485: 441: 437: 435: 432: 431: 408: 404: 398: 394: 389: 386: 385: 381: 377: 373: 369: 365: 361: 339: 336: 335: 334:be an integer, 331: 312: 309: 308: 286: 285: 283: 280: 279: 257: 256: 254: 251: 250: 228: 227: 225: 222: 221: 199: 198: 196: 193: 192: 176: 173: 172: 150: 149: 121: 120: 119: 115: 110: 107: 106: 90: 87: 86: 60: 17: 12: 11: 5: 5578: 5568: 5567: 5562: 5557: 5540: 5539: 5525: 5522: 5521: 5519: 5518: 5513: 5508: 5503: 5498: 5497: 5496: 5486: 5481: 5476: 5467: 5462: 5457: 5452: 5450:Abstract logic 5446: 5444: 5440: 5439: 5437: 5436: 5431: 5429:Turing machine 5426: 5421: 5416: 5411: 5406: 5401: 5400: 5399: 5394: 5389: 5384: 5379: 5369: 5367:Computable set 5364: 5359: 5354: 5349: 5343: 5341: 5335: 5334: 5332: 5331: 5326: 5321: 5316: 5311: 5306: 5301: 5296: 5295: 5294: 5289: 5284: 5274: 5269: 5264: 5262:Satisfiability 5259: 5254: 5249: 5248: 5247: 5237: 5236: 5235: 5225: 5224: 5223: 5218: 5213: 5208: 5203: 5193: 5192: 5191: 5186: 5179:Interpretation 5175: 5173: 5167: 5166: 5164: 5163: 5158: 5153: 5148: 5143: 5133: 5128: 5127: 5126: 5125: 5124: 5114: 5109: 5099: 5094: 5089: 5084: 5079: 5074: 5068: 5066: 5060: 5059: 5056: 5055: 5053: 5052: 5044: 5043: 5042: 5041: 5036: 5035: 5034: 5029: 5024: 5004: 5003: 5002: 5000:minimal axioms 4997: 4986: 4985: 4984: 4973: 4972: 4971: 4966: 4961: 4956: 4951: 4946: 4933: 4931: 4912: 4911: 4909: 4908: 4907: 4906: 4894: 4889: 4888: 4887: 4882: 4877: 4872: 4862: 4857: 4852: 4847: 4846: 4845: 4840: 4830: 4829: 4828: 4823: 4818: 4813: 4803: 4798: 4797: 4796: 4791: 4786: 4776: 4775: 4774: 4769: 4764: 4759: 4754: 4749: 4739: 4734: 4729: 4724: 4723: 4722: 4717: 4712: 4707: 4697: 4692: 4690:Formation rule 4687: 4682: 4681: 4680: 4675: 4665: 4664: 4663: 4653: 4648: 4643: 4638: 4632: 4626: 4609:Formal systems 4605: 4604: 4601: 4600: 4598: 4597: 4592: 4587: 4582: 4577: 4572: 4567: 4562: 4557: 4552: 4551: 4550: 4545: 4534: 4532: 4528: 4527: 4525: 4524: 4523: 4522: 4512: 4507: 4506: 4505: 4498:Large cardinal 4495: 4490: 4485: 4480: 4475: 4461: 4460: 4459: 4454: 4449: 4434: 4432: 4422: 4421: 4419: 4418: 4417: 4416: 4411: 4406: 4396: 4391: 4386: 4381: 4376: 4371: 4366: 4361: 4356: 4351: 4346: 4341: 4335: 4333: 4326: 4325: 4323: 4322: 4321: 4320: 4315: 4310: 4305: 4300: 4295: 4287: 4286: 4285: 4280: 4270: 4265: 4263:Extensionality 4260: 4258:Ordinal number 4255: 4245: 4240: 4239: 4238: 4227: 4221: 4215: 4214: 4211: 4210: 4208: 4207: 4202: 4197: 4192: 4187: 4182: 4177: 4176: 4175: 4165: 4164: 4163: 4150: 4148: 4142: 4141: 4139: 4138: 4137: 4136: 4131: 4126: 4116: 4111: 4106: 4101: 4096: 4091: 4085: 4083: 4077: 4076: 4074: 4073: 4068: 4063: 4058: 4053: 4048: 4043: 4042: 4041: 4031: 4026: 4021: 4016: 4011: 4006: 4000: 3998: 3989: 3983: 3982: 3980: 3979: 3974: 3969: 3964: 3959: 3954: 3942:Cantor's  3940: 3935: 3930: 3920: 3918: 3905: 3904: 3902: 3901: 3896: 3891: 3886: 3881: 3876: 3871: 3866: 3861: 3856: 3851: 3846: 3841: 3840: 3839: 3828: 3826: 3822: 3821: 3814: 3813: 3806: 3799: 3791: 3785: 3784: 3770: 3755: 3749: 3726: 3723: 3720: 3719: 3710: 3701: 3692: 3683: 3674: 3655:(5): 935–938. 3635: 3620: 3587: 3578: 3569: 3560: 3546:978-0897910705 3545: 3509: 3476: 3461: 3431: 3422: 3413: 3404: 3367: 3352: 3314: 3313: 3311: 3308: 3307: 3306: 3290: 3283: 3280: 3277: 3274: 3270: 3265: 3261: 3256: 3253: 3241: 3225: 3220: 3217: 3214: 3211: 3207: 3203: 3198: 3195: 3183: 3171: 3166: 3163: 3160: 3157: 3153: 3149: 3146: 3143: 3140: 3137: 3132: 3129: 3117: 3105: 3102: 3099: 3096: 3076: 3073: 3070: 3067: 3064: 3061: 3056: 3053: 3042:, and in fact 3027: 3022: 3018: 3014: 3011: 3008: 3005: 3002: 2997: 2994: 2969: 2966: 2963: 2960: 2940: 2937: 2934: 2931: 2928: 2925: 2920: 2917: 2892: 2889: 2886: 2883: 2859: 2856: 2853: 2850: 2847: 2844: 2824: 2821: 2818: 2815: 2789: 2786: 2783: 2780: 2776: 2772: 2769: 2745: 2725: 2703: 2699: 2676: 2672: 2651: 2646: 2642: 2638: 2633: 2629: 2623: 2619: 2615: 2612: 2609: 2606: 2603: 2598: 2594: 2590: 2585: 2581: 2575: 2571: 2567: 2547: 2544: 2541: 2538: 2535: 2532: 2529: 2526: 2523: 2503: 2500: 2497: 2494: 2491: 2488: 2468: 2465: 2462: 2459: 2456: 2453: 2450: 2447: 2444: 2424: 2421: 2418: 2415: 2412: 2409: 2386: 2383: 2380: 2377: 2374: 2371: 2366: 2363: 2341: 2338: 2335: 2332: 2312: 2309: 2306: 2303: 2283: 2280: 2277: 2274: 2271: 2268: 2263: 2260: 2242: 2239: 2219: 2216: 2213: 2210: 2207: 2204: 2201: 2198: 2195: 2192: 2189: 2186: 2183: 2180: 2177: 2174: 2171: 2168: 2165: 2162: 2159: 2156: 2153: 2150: 2147: 2144: 2141: 2138: 2135: 2115: 2110: 2107: 2104: 2100: 2096: 2093: 2090: 2066: 2061: 2058: 2055: 2051: 2047: 2044: 2041: 2018: 2015: 2012: 2009: 2006: 2003: 1975: 1970: 1967: 1964: 1960: 1956: 1953: 1950: 1934: 1931: 1895: 1892: 1889: 1886: 1883: 1880: 1856: 1851: 1848: 1845: 1841: 1837: 1832: 1828: 1824: 1821: 1801: 1798: 1795: 1786:, and for all 1775: 1772: 1767: 1763: 1759: 1756: 1753: 1748: 1744: 1723: 1718: 1714: 1710: 1686: 1683: 1680: 1677: 1674: 1671: 1666: 1663: 1660: 1656: 1652: 1647: 1644: 1629:be vectors of 1618: 1615: 1612: 1609: 1606: 1603: 1600: 1570: 1567: 1541: 1538: 1512: 1509: 1483: 1480: 1454: 1451: 1425: 1422: 1396: 1393: 1367: 1364: 1338: 1335: 1326: 1323: 1317: 1314: 1311: 1303: 1300: 1294: 1288: 1285: 1278: 1274: 1254: 1227: 1224: 1213: 1210: 1185: 1182: 1179: 1176: 1173: 1170: 1167: 1164: 1161: 1158: 1155: 1152: 1149: 1146: 1143: 1140: 1137: 1134: 1114: 1109: 1106: 1103: 1099: 1095: 1092: 1089: 1069: 1064: 1061: 1058: 1054: 1050: 1047: 1044: 1024: 1004: 992: 989: 951: 947: 924: 920: 892: 889: 886: 881: 878: 875: 871: 850: 847: 844: 839: 835: 806: 803: 777: 773: 748: 744: 739: 706: 701: 697: 693: 673: 670: 667: 664: 661: 658: 653: 650: 647: 643: 639: 617: 612: 608: 604: 578: 575: 572: 568: 543: 540: 537: 532: 529: 526: 522: 518: 515: 512: 509: 506: 503: 498: 494: 473: 470: 467: 464: 461: 458: 455: 452: 449: 444: 440: 417: 414: 411: 407: 401: 397: 393: 360:be vectors of 349: 346: 343: 316: 293: 290: 264: 261: 235: 232: 206: 203: 180: 157: 154: 148: 145: 142: 137: 134: 128: 125: 118: 114: 94: 59: 56: 52:Jeffrey Ullman 15: 9: 6: 4: 3: 2: 5577: 5566: 5563: 5561: 5558: 5556: 5553: 5552: 5550: 5537: 5536: 5531: 5523: 5517: 5514: 5512: 5509: 5507: 5504: 5502: 5499: 5495: 5492: 5491: 5490: 5487: 5485: 5482: 5480: 5477: 5475: 5471: 5468: 5466: 5463: 5461: 5458: 5456: 5453: 5451: 5448: 5447: 5445: 5441: 5435: 5432: 5430: 5427: 5425: 5424:Recursive set 5422: 5420: 5417: 5415: 5412: 5410: 5407: 5405: 5402: 5398: 5395: 5393: 5390: 5388: 5385: 5383: 5380: 5378: 5375: 5374: 5373: 5370: 5368: 5365: 5363: 5360: 5358: 5355: 5353: 5350: 5348: 5345: 5344: 5342: 5340: 5336: 5330: 5327: 5325: 5322: 5320: 5317: 5315: 5312: 5310: 5307: 5305: 5302: 5300: 5297: 5293: 5290: 5288: 5285: 5283: 5280: 5279: 5278: 5275: 5273: 5270: 5268: 5265: 5263: 5260: 5258: 5255: 5253: 5250: 5246: 5243: 5242: 5241: 5238: 5234: 5233:of arithmetic 5231: 5230: 5229: 5226: 5222: 5219: 5217: 5214: 5212: 5209: 5207: 5204: 5202: 5199: 5198: 5197: 5194: 5190: 5187: 5185: 5182: 5181: 5180: 5177: 5176: 5174: 5172: 5168: 5162: 5159: 5157: 5154: 5152: 5149: 5147: 5144: 5141: 5140:from ZFC 5137: 5134: 5132: 5129: 5123: 5120: 5119: 5118: 5115: 5113: 5110: 5108: 5105: 5104: 5103: 5100: 5098: 5095: 5093: 5090: 5088: 5085: 5083: 5080: 5078: 5075: 5073: 5070: 5069: 5067: 5065: 5061: 5051: 5050: 5046: 5045: 5040: 5039:non-Euclidean 5037: 5033: 5030: 5028: 5025: 5023: 5022: 5018: 5017: 5015: 5012: 5011: 5009: 5005: 5001: 4998: 4996: 4993: 4992: 4991: 4987: 4983: 4980: 4979: 4978: 4974: 4970: 4967: 4965: 4962: 4960: 4957: 4955: 4952: 4950: 4947: 4945: 4942: 4941: 4939: 4935: 4934: 4932: 4927: 4921: 4916:Example  4913: 4905: 4900: 4899: 4898: 4895: 4893: 4890: 4886: 4883: 4881: 4878: 4876: 4873: 4871: 4868: 4867: 4866: 4863: 4861: 4858: 4856: 4853: 4851: 4848: 4844: 4841: 4839: 4836: 4835: 4834: 4831: 4827: 4824: 4822: 4819: 4817: 4814: 4812: 4809: 4808: 4807: 4804: 4802: 4799: 4795: 4792: 4790: 4787: 4785: 4782: 4781: 4780: 4777: 4773: 4770: 4768: 4765: 4763: 4760: 4758: 4755: 4753: 4750: 4748: 4745: 4744: 4743: 4740: 4738: 4735: 4733: 4730: 4728: 4725: 4721: 4718: 4716: 4713: 4711: 4708: 4706: 4703: 4702: 4701: 4698: 4696: 4693: 4691: 4688: 4686: 4683: 4679: 4676: 4674: 4673:by definition 4671: 4670: 4669: 4666: 4662: 4659: 4658: 4657: 4654: 4652: 4649: 4647: 4644: 4642: 4639: 4637: 4634: 4633: 4630: 4627: 4625: 4621: 4616: 4610: 4606: 4596: 4593: 4591: 4588: 4586: 4583: 4581: 4578: 4576: 4573: 4571: 4568: 4566: 4563: 4561: 4560:Kripke–Platek 4558: 4556: 4553: 4549: 4546: 4544: 4541: 4540: 4539: 4536: 4535: 4533: 4529: 4521: 4518: 4517: 4516: 4513: 4511: 4508: 4504: 4501: 4500: 4499: 4496: 4494: 4491: 4489: 4486: 4484: 4481: 4479: 4476: 4473: 4469: 4465: 4462: 4458: 4455: 4453: 4450: 4448: 4445: 4444: 4443: 4439: 4436: 4435: 4433: 4431: 4427: 4423: 4415: 4412: 4410: 4407: 4405: 4404:constructible 4402: 4401: 4400: 4397: 4395: 4392: 4390: 4387: 4385: 4382: 4380: 4377: 4375: 4372: 4370: 4367: 4365: 4362: 4360: 4357: 4355: 4352: 4350: 4347: 4345: 4342: 4340: 4337: 4336: 4334: 4332: 4327: 4319: 4316: 4314: 4311: 4309: 4306: 4304: 4301: 4299: 4296: 4294: 4291: 4290: 4288: 4284: 4281: 4279: 4276: 4275: 4274: 4271: 4269: 4266: 4264: 4261: 4259: 4256: 4254: 4250: 4246: 4244: 4241: 4237: 4234: 4233: 4232: 4229: 4228: 4225: 4222: 4220: 4216: 4206: 4203: 4201: 4198: 4196: 4193: 4191: 4188: 4186: 4183: 4181: 4178: 4174: 4171: 4170: 4169: 4166: 4162: 4157: 4156: 4155: 4152: 4151: 4149: 4147: 4143: 4135: 4132: 4130: 4127: 4125: 4122: 4121: 4120: 4117: 4115: 4112: 4110: 4107: 4105: 4102: 4100: 4097: 4095: 4092: 4090: 4087: 4086: 4084: 4082: 4081:Propositional 4078: 4072: 4069: 4067: 4064: 4062: 4059: 4057: 4054: 4052: 4049: 4047: 4044: 4040: 4037: 4036: 4035: 4032: 4030: 4027: 4025: 4022: 4020: 4017: 4015: 4012: 4010: 4009:Logical truth 4007: 4005: 4002: 4001: 3999: 3997: 3993: 3990: 3988: 3984: 3978: 3975: 3973: 3970: 3968: 3965: 3963: 3960: 3958: 3955: 3953: 3949: 3945: 3941: 3939: 3936: 3934: 3931: 3929: 3925: 3922: 3921: 3919: 3917: 3911: 3906: 3900: 3897: 3895: 3892: 3890: 3887: 3885: 3882: 3880: 3877: 3875: 3872: 3870: 3867: 3865: 3862: 3860: 3857: 3855: 3852: 3850: 3847: 3845: 3842: 3838: 3835: 3834: 3833: 3830: 3829: 3827: 3823: 3819: 3812: 3807: 3805: 3800: 3798: 3793: 3792: 3789: 3781: 3777: 3773: 3771:0-387-98600-6 3767: 3763: 3762: 3756: 3752: 3746: 3742: 3738: 3734: 3729: 3728: 3714: 3705: 3696: 3687: 3678: 3670: 3666: 3662: 3658: 3654: 3650: 3646: 3639: 3631: 3627: 3623: 3617: 3613: 3609: 3605: 3601: 3594: 3592: 3582: 3573: 3564: 3556: 3552: 3548: 3542: 3538: 3534: 3529: 3524: 3520: 3513: 3504: 3499: 3495: 3491: 3487: 3480: 3472: 3468: 3464: 3462:0-8186-1954-6 3458: 3454: 3450: 3446: 3442: 3435: 3426: 3417: 3408: 3400: 3396: 3391: 3386: 3382: 3378: 3371: 3363: 3359: 3355: 3353:9780444105370 3349: 3345: 3341: 3337: 3333: 3329: 3325: 3319: 3315: 3304: 3278: 3272: 3268: 3263: 3242: 3239: 3215: 3209: 3205: 3184: 3161: 3155: 3147: 3144: 3141: 3118: 3100: 3094: 3068: 3062: 3041: 3020: 3012: 3009: 3006: 2983: 2982: 2981: 2964: 2958: 2932: 2926: 2904: 2887: 2881: 2854: 2848: 2845: 2842: 2819: 2813: 2784: 2778: 2770: 2716:s are either 2701: 2697: 2674: 2670: 2644: 2640: 2636: 2631: 2627: 2621: 2617: 2610: 2607: 2604: 2596: 2592: 2588: 2583: 2579: 2573: 2569: 2539: 2536: 2533: 2527: 2501: 2495: 2492: 2460: 2454: 2448: 2422: 2416: 2413: 2398: 2378: 2372: 2336: 2330: 2307: 2301: 2275: 2269: 2247: 2238: 2236: 2231: 2211: 2208: 2205: 2199: 2193: 2190: 2187: 2184: 2178: 2172: 2166: 2163: 2160: 2154: 2151: 2145: 2142: 2139: 2133: 2108: 2105: 2102: 2098: 2091: 2088: 2080: 2059: 2056: 2053: 2049: 2042: 2039: 2030: 2013: 2010: 2007: 2001: 1968: 1965: 1962: 1958: 1951: 1948: 1940: 1930: 1928: 1923: 1890: 1887: 1884: 1878: 1849: 1846: 1843: 1839: 1835: 1830: 1826: 1819: 1799: 1796: 1793: 1773: 1770: 1765: 1761: 1757: 1754: 1751: 1746: 1742: 1716: 1712: 1681: 1678: 1675: 1664: 1661: 1658: 1654: 1616: 1613: 1610: 1607: 1604: 1601: 1598: 1585: 1565: 1536: 1507: 1478: 1449: 1420: 1391: 1362: 1333: 1321: 1312: 1309: 1298: 1292: 1283: 1276: 1252: 1244: 1240: 1235: 1233: 1223: 1220: 1209: 1207: 1203: 1197: 1180: 1174: 1171: 1165: 1162: 1159: 1153: 1150: 1144: 1141: 1138: 1132: 1107: 1104: 1101: 1097: 1090: 1087: 1062: 1059: 1056: 1052: 1045: 1042: 1022: 1002: 988: 986: 981: 979: 975: 971: 967: 949: 945: 922: 918: 904: 887: 879: 876: 873: 869: 845: 837: 833: 812: 802: 800: 796: 791: 775: 771: 746: 742: 737: 699: 695: 665: 659: 656: 651: 648: 645: 641: 629: 628:s is cyclic. 610: 606: 576: 573: 570: 566: 538: 535: 530: 527: 524: 520: 513: 510: 504: 496: 492: 471: 468: 465: 462: 459: 456: 450: 442: 438: 415: 412: 409: 399: 395: 347: 344: 341: 328: 314: 288: 259: 230: 201: 178: 152: 143: 140: 135: 132: 123: 116: 92: 84: 80: 76: 72: 68: 65: 55: 53: 49: 45: 40: 38: 34: 30: 26: 22: 5526: 5324:Ultraproduct 5171:Model theory 5136:Independence 5072:Formal proof 5064:Proof theory 5047: 5020: 4977:real numbers 4949:second-order 4860:Substitution 4737:Metalanguage 4678:conservative 4651:Axiom schema 4595:Constructive 4565:Morse–Kelley 4531:Set theories 4510:Aleph number 4503:inaccessible 4409:Grothendieck 4293:intersection 4184: 4180:Higher-order 4168:Second-order 4114:Truth tables 4071:Venn diagram 3854:Formal proof 3764:. Springer. 3760: 3732: 3713: 3704: 3695: 3686: 3677: 3652: 3648: 3638: 3603: 3581: 3572: 3563: 3518: 3512: 3493: 3489: 3479: 3444: 3434: 3425: 3416: 3407: 3380: 3370: 3335: 3331: 3318: 3301:is equal to 3236:is equal to 2905: 2399: 2248: 2244: 2232: 2031: 1938: 1936: 1924: 1586: 1242: 1238: 1236: 1229: 1215: 1205: 1201: 1198: 994: 982: 973: 905: 810: 808: 794: 792: 630: 329: 74: 70: 66: 61: 41: 24: 18: 5434:Type theory 5382:undecidable 5314:Truth value 5201:equivalence 4880:non-logical 4493:Enumeration 4483:Isomorphism 4430:cardinality 4414:Von Neumann 4379:Ultrafilter 4344:Uncountable 4278:equivalence 4195:Quantifiers 4185:Fixed-point 4154:First-order 4034:Consistency 4019:Proposition 3996:Traditional 3967:Lindström's 3957:Compactness 3899:Type theory 3844:Cardinality 1208:)-formula. 364:variables, 5549:Categories 5245:elementary 4938:arithmetic 4806:Quantifier 4784:functional 4656:Expression 4374:Transitive 4318:identities 4303:complement 4236:hereditary 4219:Set theory 3725:References 3621:0897910990 2662:where the 2241:Iterations 1994:such that 1734:such that 1584:coincide. 430:such that 372:, and let 48:Alfred Aho 5516:Supertask 5419:Recursion 5377:decidable 5211:saturated 5189:of models 5112:deductive 5107:axiomatic 5027:Hilbert's 5014:Euclidean 4995:canonical 4918:axiomatic 4850:Signature 4779:Predicate 4668:Extension 4590:Ackermann 4515:Operation 4394:Universal 4384:Recursive 4359:Singleton 4354:Inhabited 4339:Countable 4329:Types of 4313:power set 4283:partition 4200:Predicate 4146:Predicate 4061:Syllogism 4051:Soundness 4024:Inference 4014:Tautology 3916:paradoxes 3780:901297152 3669:0097-5397 3523:CiteSeerX 3471:206437693 3362:0049-237X 3145:⁡ 3010:⁡ 2846:∗ 2744:∃ 2724:∀ 2671:ϕ 2641:ϕ 2593:ϕ 2537:∧ 2525:∃ 2490:∃ 2458:⇒ 2446:∀ 2411:∀ 2200:ϕ 2197:¬ 2194:∨ 2176:∀ 2173:∧ 2155:ϕ 2134:ψ 2099:ψ 2092:⁡ 2050:ϕ 2043:⁡ 2002:ϕ 1959:ϕ 1952:⁡ 1879:ϕ 1820:ϕ 1655:ϕ 1569:→ 1540:→ 1511:→ 1482:→ 1453:→ 1424:→ 1395:→ 1366:→ 1337:→ 1325:→ 1313:φ 1310:⁡ 1302:→ 1287:→ 1172:∨ 1154:ϕ 1133:ψ 1098:ψ 1091:⁡ 1053:ϕ 1046:⁡ 660:φ 657:⁡ 574:− 554:(meaning 528:− 514:φ 413:∈ 292:→ 263:→ 234:→ 205:→ 156:→ 144:φ 141:⁡ 127:→ 5501:Logicism 5494:timeline 5470:Concrete 5329:Validity 5299:T-schema 5292:Kripke's 5287:Tarski's 5282:semantic 5272:Strength 5221:submodel 5216:spectrum 5184:function 5032:Tarski's 5021:Elements 5008:geometry 4964:Robinson 4885:variable 4870:function 4843:spectrum 4833:Sentence 4789:variable 4732:Language 4685:Relation 4646:Automata 4636:Alphabet 4620:language 4474:-jection 4452:codomain 4438:Function 4399:Universe 4369:Infinite 4273:Relation 4056:Validity 4046:Argument 3944:theorem, 3326:(1974). 2806:written 2514:to mean 2435:to mean 1352:, where 966:Immerman 171:, where 5443:Related 5240:Diagram 5138: ( 5117:Hilbert 5102:Systems 5097:Theorem 4975:of the 4920:systems 4700:Formula 4695:Grammar 4611: ( 4555:General 4268:Forcing 4253:Element 4173:Monadic 3948:paradox 3889:Theorem 3825:General 3630:7503265 3555:7869248 3399:3242505 2903:times. 2294:; here 985:Datalog 825:, then 37:Datalog 5206:finite 4969:Skolem 4922:  4897:Theory 4865:Symbol 4855:String 4838:atomic 4715:ground 4710:closed 4705:atomic 4661:ground 4624:syntax 4520:binary 4447:domain 4364:Finite 4129:finite 3987:Logics 3946:  3894:Theory 3778:  3768:  3747:  3667:  3628:  3618:  3553:  3543:  3525:  3469:  3459:  3397:  3360:  3350:  3303:PSPACE 2126:where 1869:φ 1125:where 815:φ 799:PSPACE 556:φ 374:φ 77:using 62:For a 5196:Model 4944:Peano 4801:Proof 4641:Arity 4570:Naive 4457:image 4389:Fuzzy 4349:Empty 4298:union 4243:Class 3884:Model 3874:Lemma 3832:Axiom 3626:S2CID 3551:S2CID 3467:S2CID 3395:S2CID 3310:Notes 3238:PTIME 2756:. If 1219:arity 970:Vardi 558:with 69:, FO( 5319:Type 5122:list 4926:list 4903:list 4892:Term 4826:rank 4720:open 4614:list 4426:Maps 4331:sets 4190:Free 4160:list 3910:list 3837:list 3776:OCLC 3766:ISBN 3745:ISBN 3665:ISSN 3616:ISBN 3541:ISBN 3457:ISBN 3358:ISSN 3348:ISBN 2479:and 2081:for 1918:and 1910:and 1797:< 1555:and 1439:and 1381:and 1196:. 968:and 484:and 380:and 330:Let 278:and 50:and 5006:of 4988:of 4936:of 4468:Sur 4442:Map 4249:Ur- 4231:Set 3737:doi 3657:doi 3608:doi 3533:doi 3498:doi 3449:doi 3385:doi 3340:doi 3142:log 3007:log 2736:or 2237:. 2077:is 2040:DTC 1949:DTC 1937:FO( 1237:FO( 1200:FO( 1088:PFP 1080:as 1043:IFP 903:). 717:on 642:PFP 327:. 117:PFP 93:PFP 19:In 5551:: 5392:NP 5016:: 5010:: 4940:: 4617:), 4472:Bi 4464:In 3774:. 3743:. 3663:. 3653:17 3651:. 3647:. 3624:. 3614:. 3602:. 3590:^ 3549:. 3539:. 3531:. 3494:68 3492:. 3488:. 3465:. 3455:. 3443:. 3393:. 3379:. 3356:. 3346:. 3338:. 3336:77 3334:. 3330:. 3040:AC 2397:. 2230:. 2089:TC 2029:. 1927:NL 1922:. 1812:, 1526:, 1497:, 1277:TC 1253:TC 801:. 81:, 39:. 23:, 5472:/ 5387:P 5142:) 4928:) 4924:( 4821:∀ 4816:! 4811:∃ 4772:= 4767:↔ 4762:→ 4757:∧ 4752:√ 4747:ÂŹ 4470:/ 4466:/ 4440:/ 4251:) 4247:( 4134:∞ 4124:3 3912:) 3810:e 3803:t 3796:v 3782:. 3753:. 3739:: 3671:. 3659:: 3632:. 3610:: 3557:. 3535:: 3506:. 3500:: 3473:. 3451:: 3401:. 3387:: 3364:. 3342:: 3289:] 3282:) 3279:1 3276:( 3273:O 3269:n 3264:2 3260:[ 3255:O 3252:F 3224:] 3219:) 3216:1 3213:( 3210:O 3206:n 3202:[ 3197:O 3194:F 3170:] 3165:) 3162:1 3159:( 3156:O 3152:) 3148:n 3139:( 3136:[ 3131:O 3128:F 3116:. 3104:) 3101:n 3098:( 3095:t 3075:] 3072:) 3069:n 3066:( 3063:t 3060:[ 3055:O 3052:F 3026:] 3021:i 3017:) 3013:n 3004:( 3001:[ 2996:O 2993:F 2968:) 2965:n 2962:( 2959:t 2939:] 2936:) 2933:n 2930:( 2927:t 2924:[ 2919:O 2916:F 2891:) 2888:n 2885:( 2882:t 2872:k 2858:) 2855:n 2852:( 2849:t 2843:k 2823:) 2820:n 2817:( 2814:t 2804:Q 2788:) 2785:n 2782:( 2779:t 2775:] 2771:Q 2768:[ 2758:Q 2702:i 2698:Q 2675:i 2650:) 2645:k 2637:, 2632:k 2628:x 2622:k 2618:Q 2614:( 2611:. 2608:. 2605:. 2602:) 2597:1 2589:, 2584:1 2580:x 2574:1 2570:Q 2566:( 2546:) 2543:) 2540:Q 2534:P 2531:( 2528:x 2522:( 2502:Q 2499:) 2496:P 2493:x 2487:( 2467:) 2464:) 2461:Q 2455:P 2452:( 2449:x 2443:( 2423:Q 2420:) 2417:P 2414:x 2408:( 2385:] 2382:) 2379:n 2376:( 2373:t 2370:[ 2365:O 2362:F 2340:) 2337:n 2334:( 2331:t 2311:) 2308:n 2305:( 2302:t 2282:] 2279:) 2276:n 2273:( 2270:t 2267:[ 2262:O 2259:F 2235:L 2218:) 2215:) 2212:x 2209:, 2206:u 2203:( 2191:v 2188:= 2185:x 2182:( 2179:x 2170:) 2167:v 2164:, 2161:u 2158:( 2152:= 2149:) 2146:v 2143:, 2140:u 2137:( 2114:) 2109:v 2106:, 2103:u 2095:( 2065:) 2060:v 2057:, 2054:u 2046:( 2017:) 2014:v 2011:, 2008:u 2005:( 1992:v 1988:u 1974:) 1969:v 1966:, 1963:u 1955:( 1939:X 1920:y 1916:x 1912:v 1908:u 1894:) 1891:y 1888:, 1885:x 1882:( 1855:) 1850:1 1847:+ 1844:i 1840:z 1836:, 1831:i 1827:z 1823:( 1800:n 1794:i 1774:y 1771:= 1766:n 1762:z 1758:, 1755:x 1752:= 1747:1 1743:z 1722:) 1717:i 1713:z 1709:( 1699:n 1685:) 1682:y 1679:, 1676:x 1673:( 1670:) 1665:v 1662:, 1659:u 1651:( 1646:C 1643:T 1631:k 1617:y 1614:, 1611:x 1608:, 1605:v 1602:, 1599:u 1589:k 1566:t 1537:s 1508:y 1479:x 1450:s 1421:t 1392:y 1363:x 1334:t 1322:s 1316:] 1299:y 1293:, 1284:x 1273:[ 1243:X 1239:X 1206:X 1202:X 1184:) 1181:x 1178:( 1175:P 1169:) 1166:x 1163:, 1160:P 1157:( 1151:= 1148:) 1145:x 1142:, 1139:P 1136:( 1113:) 1108:x 1105:, 1102:P 1094:( 1068:) 1063:x 1060:, 1057:P 1049:( 1023:P 1003:P 978:P 974:X 950:k 946:n 923:k 919:n 908:P 891:) 888:x 885:( 880:1 877:+ 874:i 870:P 849:) 846:x 843:( 838:i 834:P 823:P 819:P 795:X 776:i 772:P 747:k 743:n 738:2 727:k 723:P 719:y 705:) 700:i 696:P 692:( 672:] 669:) 666:y 663:( 652:x 649:, 646:P 638:[ 616:) 611:i 607:P 603:( 593:P 577:1 571:i 567:P 542:) 539:x 536:, 531:1 525:i 521:P 517:( 511:= 508:) 505:x 502:( 497:i 493:P 472:e 469:s 466:l 463:a 460:f 457:= 454:) 451:x 448:( 443:0 439:P 416:N 410:i 406:) 400:i 396:P 392:( 382:P 378:x 370:k 366:P 362:k 348:y 345:, 342:x 332:k 315:P 289:t 260:x 231:t 202:x 179:P 153:t 147:] 136:P 133:, 124:x 113:[ 75:X 71:X 67:X

Index

mathematical logic
descriptive complexity theory
database query languages
Datalog
Yiannis N. Moschovakis
Alfred Aho
Jeffrey Ullman
relational signature
first-order connectives and predicates
second-order variables
PSPACE
Immerman
Vardi
P
Datalog
arity
transitive closures
NL
syntactic sugar
L
AC
PTIME
PSPACE
Moschovakis, Yiannis N.
"Elementary Induction on Abstract Structures"
doi
10.1016/s0049-237x(08)x7092-2
ISBN
9780444105370
ISSN

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

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