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Rosser's trick

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While Gödel's original proof uses a sentence that says (informally) "This sentence is not provable", Rosser's trick uses a formula that says "If this sentence is provable, there is a shorter proof of its negation".
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is consistent then it cannot prove its Gödel sentence; but in order to show that the negation of the Gödel sentence is also not provable, it is necessary to add a stronger assumption that the theory is
1124: 377: 2220: 700: 3205: 3095: 1791: 1597: 1898: 3028: 2564: 2494: 965: 3760: 1744: 1639: 774: 2855: 1450: 1313: 2629: 881: 124: 3383: 326: 1320: 912: 810:. Rosser (1936) constructed a different self-referential sentence that can be used to replace the Gödel sentence in Gödel's proof, removing the need to assume ω-consistency. 522: 451: 3720: 3657: 3426: 3248: 2401: 2025: 1702: 808: 545: 287: 2077: 2051: 3614: 3348: 3288: 3138: 2958: 2898: 2357: 2314: 2240: 2175: 2124: 2002: 1854: 1659: 1550: 655: 615: 588: 491: 264: 1982: 3697: 3677: 3634: 3594: 3524: 3446: 3403: 3328: 3308: 3268: 3225: 3158: 3118: 3048: 2978: 2938: 2918: 2878: 2811: 2791: 2709: 2689: 2669: 2649: 2584: 2514: 2444: 2424: 2378: 2337: 2294: 2265: 2144: 2097: 1834: 1811: 1679: 1530: 1510: 1490: 1470: 836: 720: 635: 568: 471: 420: 397: 244: 224: 204: 184: 164: 144: 76: 1903: 3506:. But by the immediate consequence of the definition of Rosser's provability predicate, mentioned in the previous section, it follows that 3451: 2714: 3529: 331: 2180: 660: 3163: 3053: 1749: 1555: 35: 1859: 2983: 2519: 2449: 2099:
only needs to prove that such a situation cannot hold for any two numbers, as well as to include some first-order logic)
920: 1707: 1602: 730: 2816: 1411: 1274: 3753: 2589: 1110:{\displaystyle \operatorname {Proof} _{T}^{R}(x,y)\equiv \operatorname {Proof} _{T}(x,y)\land \lnot \exists z\leq x,} 841: 84: 3356: 1262:{\displaystyle \lnot \operatorname {Proof} _{T}^{R}(x,y)\equiv \operatorname {Proof} _{T}(x,y)\to \exists z\leq x.} 292: 46:
in 1936, as an improvement of Gödel's original proof of the incompleteness theorems that was published in 1931.
2566:. This is shown in a similar manner to what is done in Gödel's proof of the first incompleteness theorem: 3825: 78:
is selected which is effective, consistent, and includes a sufficient fragment of elementary arithmetic.
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be an effective, consistent theory including a sufficient amount of arithmetic, with Rosser sentence
886: 496: 425: 1399:{\displaystyle \operatorname {Pvbl} _{T}^{R}(y)\equiv \exists x\operatorname {Proof} _{T}^{R}(x,y).} 3809: 3100:
The proof of (1) is similar to that in Gödel's proof of the first incompleteness theorem: Assume
547:. The negation function may take any value whatsoever for inputs that are not codes of formulas. 3702: 3639: 3408: 3230: 2383: 2007: 1684: 783: 527: 2793:
includes enough arithmetic (in fact, what is required is basic first-order logic) ensures that
2631:, a relation between two concrete natural numbers; one then goes over all the natural numbers 269: 2056: 2030: 3599: 3333: 3273: 3123: 2943: 2883: 2342: 2299: 2225: 2160: 2109: 1987: 1839: 1644: 1535: 640: 593: 573: 476: 249: 42:(Smorynski 1977, p. 840; Mendelson 1977, p. 160). This method was introduced by 8: 1961: 20: 3790: 3782: 3682: 3662: 3619: 3579: 3509: 3431: 3388: 3313: 3293: 3253: 3210: 3143: 3103: 3033: 2963: 2923: 2903: 2863: 2796: 2776: 2694: 2674: 2654: 2634: 2569: 2499: 2429: 2409: 2363: 2322: 2279: 2250: 2129: 2082: 1819: 1796: 1664: 1515: 1495: 1475: 1455: 821: 705: 620: 553: 456: 405: 382: 229: 209: 189: 169: 149: 129: 61: 58:
Rosser's trick begins with the assumptions of Gödel's incompleteness theorem. A theory
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This modified proof predicate is used to define a modified provability predicate
2103: 206:. (In the remainder of this article, no distinction is made between the number 3819: 777: 3745: 3786: 1951:{\displaystyle \neg \operatorname {Pvbl} _{T}^{R}({\text{neg}}(\phi ))} 1836:
includes enough arithmetic, then it can prove that for every formula
3778: 3499:{\displaystyle \operatorname {Pvbl} _{T}^{R}({\text{neg}}\#(\rho ))} 2763:{\displaystyle \neg \operatorname {Proof} _{T}(z,{\text{(neg}}(y))} 1793:
have different properties from the point of view of provability in
38:
not relying on the assumption that the theory being considered is
2940:, and there is no number coding for the proof of the negation of 81:
Gödel's proof shows that for any such theory there is a formula
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such that there is no smaller coded proof of the negation of
379:. It is intended to define the set of formulas provable from 146:
is a natural number code (a Gödel number) for a formula and
3569:{\displaystyle \neg \operatorname {Pvbl} _{T}^{R}(\#\rho )} 2406:
In order to prove this, one first shows that for a formula
19:
For the theorem about the sparseness of prime numbers, see
2316:. Then the following hold (Mendelson 1977, p. 160): 914:
be the associated proof predicate and negation function.
422:
also show that it is able to define a negation function
372:{\displaystyle \exists x\operatorname {Proof} _{T}(x,y)} 2215:{\displaystyle \neg \operatorname {Pvbl} _{T}(\#\rho )} 695:{\displaystyle \neg \operatorname {Pvbl} _{T}(\#\phi )} 3200:{\displaystyle \operatorname {Pvbl} _{T}^{R}(\#\rho )} 3090:{\displaystyle \operatorname {Pvbl} _{T}^{R}(\#\phi )} 1816:
An immediate consequence of the definition is that if
1786:{\displaystyle \operatorname {Pvbl} _{T}^{R}(\#\phi )} 1592:{\displaystyle \operatorname {Pvbl} _{T}^{R}(\#\phi )} 3705: 3685: 3665: 3642: 3622: 3602: 3582: 3532: 3512: 3454: 3434: 3428:; then it follows, by the previous elaboration, that 3411: 3391: 3359: 3336: 3316: 3296: 3276: 3256: 3233: 3213: 3166: 3146: 3140:; then it follows, by the previous elaboration, that 3126: 3106: 3056: 3036: 2986: 2966: 2946: 2926: 2906: 2886: 2866: 2819: 2799: 2779: 2717: 2697: 2677: 2657: 2637: 2592: 2572: 2522: 2502: 2452: 2432: 2412: 2386: 2366: 2345: 2325: 2302: 2282: 2253: 2228: 2183: 2163: 2132: 2112: 2085: 2059: 2033: 2010: 1990: 1964: 1906: 1862: 1842: 1822: 1799: 1752: 1710: 1687: 1667: 1647: 1605: 1558: 1538: 1518: 1498: 1478: 1458: 1414: 1323: 1277: 1127: 975: 923: 889: 844: 824: 786: 733: 708: 663: 643: 623: 596: 576: 556: 530: 499: 479: 459: 428: 408: 385: 334: 295: 272: 252: 232: 212: 192: 172: 152: 132: 87: 64: 3740:
Smorynski (1977), "The incompleteness theorems", in
1893:{\displaystyle \operatorname {Pvbl} _{T}^{R}(\phi )} 166:
is the Gödel number for a proof, from the axioms of
3023:{\displaystyle \operatorname {Proof} _{T}^{R}(e,y)} 2770:, again, a relation between two concrete numbers. 2559:{\displaystyle \operatorname {Proof} _{T}^{R}(e,y)} 2489:{\displaystyle \operatorname {Proof} _{T}^{R}(e,y)} 1958:. This is because otherwise, there are two numbers 1641:holds, because if there is a code for the proof of 960:{\displaystyle \operatorname {Proof} _{T}^{R}(x,y)} 3714: 3691: 3671: 3651: 3628: 3608: 3588: 3568: 3518: 3498: 3440: 3420: 3397: 3377: 3353:The proof of (2) also uses the particular form of 3342: 3322: 3302: 3282: 3262: 3242: 3219: 3199: 3152: 3132: 3112: 3089: 3042: 3022: 2972: 2952: 2932: 2912: 2892: 2872: 2849: 2805: 2785: 2762: 2703: 2683: 2663: 2643: 2623: 2578: 2558: 2508: 2488: 2438: 2418: 2395: 2372: 2351: 2331: 2308: 2288: 2259: 2234: 2214: 2169: 2138: 2118: 2091: 2071: 2045: 2019: 1996: 1976: 1950: 1892: 1848: 1828: 1805: 1785: 1739:{\displaystyle \operatorname {Pvbl} _{T}(\#\phi )} 1738: 1696: 1673: 1653: 1634:{\displaystyle \operatorname {Pvbl} _{T}(\#\phi )} 1633: 1591: 1544: 1524: 1504: 1484: 1464: 1444: 1398: 1307: 1261: 1109: 959: 906: 875: 830: 802: 769:{\displaystyle T={\text{PA}}+\neg {\text{G}}_{PA}} 768: 714: 694: 649: 629: 609: 582: 562: 539: 516: 485: 465: 445: 414: 391: 371: 320: 281: 258: 238: 218: 198: 178: 158: 138: 118: 70: 3761:"Extensions of some theorems of Gödel and Church" 727:, not merely consistent. For example, the theory 3817: 2850:{\displaystyle \operatorname {Pvbl} _{T}^{R}(y)} 1445:{\displaystyle \operatorname {Pvbl} _{T}^{R}(y)} 1308:{\displaystyle \operatorname {Pvbl} _{T}^{R}(y)} 2624:{\displaystyle \operatorname {Proof} _{T}(e,y)} 876:{\displaystyle \operatorname {Proof} _{T}(x,y)} 119:{\displaystyle \operatorname {Proof} _{T}(x,y)} 3758: 3679:is consistent. We are forced to conclude that 3378:{\displaystyle \operatorname {Proof} _{T}^{R}} 3310:is consistent. We are forced to conclude that 321:{\displaystyle \operatorname {Pvbl} _{T}(y)} 3818: 813: 1661:, then (following the consistency of 34:is a method for proving a variant of 1681:) there is no code for the proof of 126:which has the intended meaning that 2271: 13: 3736:Introduction to Mathematical Logic 3706: 3643: 3557: 3533: 3481: 3412: 3234: 3188: 3078: 2718: 2387: 2203: 2184: 2011: 1907: 1774: 1727: 1688: 1622: 1580: 1354: 1198: 1128: 1046: 1043: 787: 748: 683: 664: 531: 335: 273: 246:, and the number coding a formula 14: 3837: 3802: 3759:Barkley Rosser (September 1936). 1472:is provable via some coded proof 550:The Gödel sentence of the theory 3810:Computability and Incompleteness 2027:, respectively, satisfying both 1532:is consistent, for each formula 818:For a fixed arithmetical theory 907:{\displaystyle {\text{neg}}(x)} 517:{\displaystyle {\text{neg}}(y)} 446:{\displaystyle {\text{neg}}(y)} 36:Gödel's incompleteness theorems 3742:Handbook of Mathematical Logic 3563: 3554: 3493: 3490: 3484: 3473: 3194: 3185: 3084: 3075: 3017: 3005: 2844: 2838: 2757: 2754: 2748: 2734: 2618: 2606: 2553: 2541: 2483: 2471: 2209: 2200: 1945: 1942: 1936: 1928: 1887: 1881: 1780: 1771: 1733: 1724: 1628: 1619: 1586: 1577: 1439: 1433: 1390: 1378: 1348: 1342: 1302: 1296: 1253: 1250: 1247: 1241: 1226: 1210: 1195: 1192: 1180: 1161: 1149: 1101: 1098: 1095: 1089: 1074: 1058: 1037: 1025: 1006: 994: 954: 942: 901: 895: 870: 858: 702:. Gödel's proof shows that if 689: 680: 511: 505: 440: 434: 366: 354: 315: 309: 113: 101: 1: 3725: 53: 3748:, Ed., North Holland, 1982, 3659:, and this is impossible if 3290:, and this is impossible if 1512:. Under the assumption that 453:, with the property that if 289:.) Furthermore, the formula 186:, of the formula encoded by 16:Method in mathematical logic 7: 1984:, coding for the proofs of 917:A modified proof predicate 226:and the formula encoded by 10: 3842: 3715:{\displaystyle \neg \rho } 3652:{\displaystyle \neg \rho } 3421:{\displaystyle \neg \rho } 3243:{\displaystyle \neg \rho } 2396:{\displaystyle \neg \rho } 2020:{\displaystyle \neg \phi } 1697:{\displaystyle \neg \phi } 803:{\displaystyle \neg G_{T}} 540:{\displaystyle \neg \phi } 524:is a code for the formula 18: 3766:Journal of Symbolic Logic 2900:, then there is a number 2880:is consistent and proves 2671:one by one, and for each 1599:will hold if and only if 2920:coding for its proof in 473:is a code for a formula 2126:be a formula such that 282:{\displaystyle \#\phi } 3716: 3693: 3673: 3653: 3630: 3610: 3590: 3570: 3520: 3500: 3442: 3422: 3399: 3379: 3344: 3324: 3304: 3284: 3264: 3244: 3221: 3201: 3154: 3134: 3114: 3091: 3044: 3024: 2974: 2954: 2934: 2914: 2894: 2874: 2851: 2807: 2787: 2764: 2705: 2685: 2665: 2645: 2625: 2580: 2560: 2510: 2490: 2440: 2420: 2397: 2374: 2353: 2333: 2310: 2290: 2261: 2236: 2216: 2171: 2140: 2120: 2093: 2073: 2072:{\displaystyle m<n} 2047: 2046:{\displaystyle n<m} 2021: 1998: 1978: 1952: 1894: 1850: 1830: 1807: 1787: 1740: 1698: 1675: 1655: 1635: 1593: 1546: 1526: 1506: 1486: 1466: 1446: 1400: 1309: 1263: 1111: 961: 908: 877: 832: 804: 770: 716: 696: 651: 631: 611: 584: 564: 541: 518: 487: 467: 447: 416: 393: 373: 322: 283: 260: 240: 220: 200: 180: 160: 140: 120: 72: 3717: 3694: 3674: 3654: 3631: 3611: 3609:{\displaystyle \rho } 3591: 3571: 3521: 3501: 3443: 3423: 3400: 3380: 3345: 3343:{\displaystyle \rho } 3325: 3305: 3285: 3283:{\displaystyle \rho } 3265: 3245: 3222: 3202: 3155: 3135: 3133:{\displaystyle \rho } 3115: 3092: 3045: 3025: 2975: 2955: 2953:{\displaystyle \phi } 2935: 2915: 2895: 2893:{\displaystyle \phi } 2875: 2852: 2808: 2788: 2765: 2706: 2686: 2666: 2646: 2626: 2581: 2561: 2511: 2491: 2441: 2421: 2398: 2375: 2354: 2352:{\displaystyle \rho } 2334: 2311: 2309:{\displaystyle \rho } 2291: 2262: 2237: 2235:{\displaystyle \rho } 2217: 2172: 2170:{\displaystyle \rho } 2141: 2121: 2119:{\displaystyle \rho } 2094: 2074: 2048: 2022: 1999: 1997:{\displaystyle \phi } 1979: 1953: 1895: 1851: 1849:{\displaystyle \phi } 1831: 1808: 1788: 1741: 1699: 1676: 1656: 1654:{\displaystyle \phi } 1636: 1594: 1547: 1545:{\displaystyle \phi } 1527: 1507: 1487: 1467: 1447: 1401: 1310: 1264: 1112: 962: 909: 878: 833: 805: 771: 717: 697: 652: 650:{\displaystyle \phi } 632: 612: 610:{\displaystyle G_{T}} 585: 583:{\displaystyle \phi } 565: 542: 519: 488: 486:{\displaystyle \phi } 468: 448: 417: 394: 374: 323: 284: 261: 259:{\displaystyle \phi } 241: 221: 201: 181: 161: 141: 121: 73: 3703: 3683: 3663: 3640: 3620: 3600: 3580: 3530: 3510: 3452: 3432: 3409: 3389: 3357: 3334: 3314: 3294: 3274: 3254: 3231: 3211: 3164: 3144: 3124: 3104: 3054: 3034: 2984: 2964: 2944: 2924: 2904: 2884: 2864: 2817: 2797: 2777: 2773:The assumption that 2715: 2695: 2675: 2655: 2635: 2590: 2570: 2520: 2500: 2450: 2430: 2410: 2384: 2364: 2343: 2323: 2300: 2280: 2251: 2226: 2181: 2161: 2130: 2110: 2083: 2057: 2031: 2008: 1988: 1962: 1904: 1860: 1840: 1820: 1797: 1750: 1708: 1685: 1665: 1645: 1603: 1556: 1536: 1516: 1496: 1476: 1456: 1412: 1321: 1275: 1125: 973: 921: 887: 842: 822: 784: 731: 706: 661: 641: 621: 594: 590:, sometimes denoted 574: 554: 528: 497: 477: 457: 426: 406: 383: 332: 293: 270: 250: 230: 210: 190: 170: 150: 130: 85: 62: 3550: 3469: 3374: 3181: 3071: 3001: 2834: 2537: 2467: 1977:{\displaystyle n,m} 1924: 1877: 1767: 1573: 1429: 1374: 1338: 1292: 1145: 990: 938: 814:The Rosser sentence 402:The assumptions on 3826:Mathematical logic 3712: 3689: 3669: 3649: 3626: 3606: 3586: 3566: 3536: 3516: 3496: 3455: 3438: 3418: 3395: 3375: 3360: 3340: 3320: 3300: 3280: 3260: 3240: 3217: 3197: 3167: 3150: 3130: 3110: 3087: 3057: 3040: 3020: 2987: 2970: 2950: 2930: 2910: 2890: 2870: 2847: 2820: 2803: 2783: 2760: 2701: 2681: 2661: 2641: 2621: 2576: 2556: 2523: 2506: 2486: 2453: 2436: 2416: 2393: 2370: 2349: 2329: 2306: 2286: 2257: 2232: 2212: 2167: 2136: 2116: 2089: 2069: 2043: 2017: 1994: 1974: 1948: 1910: 1890: 1863: 1846: 1826: 1803: 1783: 1753: 1736: 1694: 1671: 1651: 1631: 1589: 1559: 1542: 1522: 1502: 1482: 1462: 1452:is the claim that 1442: 1415: 1396: 1360: 1324: 1305: 1278: 1259: 1131: 1107: 976: 957: 924: 904: 873: 828: 800: 766: 712: 692: 647: 627: 607: 580: 560: 537: 514: 483: 463: 443: 412: 389: 369: 318: 279: 256: 236: 216: 196: 176: 156: 136: 116: 68: 28:mathematical logic 3812:", lecture notes. 3692:{\displaystyle T} 3672:{\displaystyle T} 3629:{\displaystyle T} 3616:. But we assumed 3589:{\displaystyle T} 3519:{\displaystyle T} 3479: 3441:{\displaystyle T} 3398:{\displaystyle T} 3323:{\displaystyle T} 3303:{\displaystyle T} 3263:{\displaystyle T} 3250:. But we assumed 3220:{\displaystyle T} 3153:{\displaystyle T} 3113:{\displaystyle T} 3043:{\displaystyle T} 2973:{\displaystyle T} 2933:{\displaystyle T} 2913:{\displaystyle e} 2873:{\displaystyle T} 2806:{\displaystyle T} 2786:{\displaystyle T} 2746: 2704:{\displaystyle T} 2684:{\displaystyle z} 2664:{\displaystyle e} 2644:{\displaystyle z} 2579:{\displaystyle T} 2509:{\displaystyle T} 2439:{\displaystyle e} 2419:{\displaystyle y} 2373:{\displaystyle T} 2332:{\displaystyle T} 2289:{\displaystyle T} 2260:{\displaystyle T} 2146:proves ρ ↔ ÂŹ Pvbl 2139:{\displaystyle T} 2092:{\displaystyle T} 1934: 1829:{\displaystyle T} 1806:{\displaystyle T} 1674:{\displaystyle T} 1525:{\displaystyle T} 1505:{\displaystyle y} 1485:{\displaystyle x} 1465:{\displaystyle y} 1119:which means that 893: 831:{\displaystyle T} 776:, in which PA is 755: 743: 715:{\displaystyle T} 630:{\displaystyle T} 563:{\displaystyle T} 503: 466:{\displaystyle y} 432: 415:{\displaystyle T} 392:{\displaystyle T} 239:{\displaystyle y} 219:{\displaystyle y} 199:{\displaystyle y} 179:{\displaystyle T} 159:{\displaystyle x} 139:{\displaystyle y} 71:{\displaystyle T} 44:J. Barkley Rosser 40:ω-consistent 3833: 3808:Avigad (2007), " 3798: 3721: 3719: 3718: 3713: 3698: 3696: 3695: 3690: 3678: 3676: 3675: 3670: 3658: 3656: 3655: 3650: 3635: 3633: 3632: 3627: 3615: 3613: 3612: 3607: 3595: 3593: 3592: 3587: 3575: 3573: 3572: 3567: 3549: 3544: 3525: 3523: 3522: 3517: 3505: 3503: 3502: 3497: 3480: 3477: 3468: 3463: 3447: 3445: 3444: 3439: 3427: 3425: 3424: 3419: 3404: 3402: 3401: 3396: 3384: 3382: 3381: 3376: 3373: 3368: 3349: 3347: 3346: 3341: 3329: 3327: 3326: 3321: 3309: 3307: 3306: 3301: 3289: 3287: 3286: 3281: 3269: 3267: 3266: 3261: 3249: 3247: 3246: 3241: 3226: 3224: 3223: 3218: 3206: 3204: 3203: 3198: 3180: 3175: 3159: 3157: 3156: 3151: 3139: 3137: 3136: 3131: 3119: 3117: 3116: 3111: 3096: 3094: 3093: 3088: 3070: 3065: 3049: 3047: 3046: 3041: 3030:holds, and thus 3029: 3027: 3026: 3021: 3000: 2995: 2979: 2977: 2976: 2971: 2959: 2957: 2956: 2951: 2939: 2937: 2936: 2931: 2919: 2917: 2916: 2911: 2899: 2897: 2896: 2891: 2879: 2877: 2876: 2871: 2860:Furthermore, if 2856: 2854: 2853: 2848: 2833: 2828: 2812: 2810: 2809: 2804: 2792: 2790: 2789: 2784: 2769: 2767: 2766: 2761: 2747: 2744: 2730: 2729: 2710: 2708: 2707: 2702: 2690: 2688: 2687: 2682: 2670: 2668: 2667: 2662: 2650: 2648: 2647: 2642: 2630: 2628: 2627: 2622: 2602: 2601: 2585: 2583: 2582: 2577: 2565: 2563: 2562: 2557: 2536: 2531: 2515: 2513: 2512: 2507: 2495: 2493: 2492: 2487: 2466: 2461: 2445: 2443: 2442: 2437: 2425: 2423: 2422: 2417: 2402: 2400: 2399: 2394: 2379: 2377: 2376: 2371: 2358: 2356: 2355: 2350: 2338: 2336: 2335: 2330: 2315: 2313: 2312: 2307: 2295: 2293: 2292: 2287: 2272:Rosser's theorem 2268: 2266: 2264: 2263: 2258: 2241: 2239: 2238: 2233: 2221: 2219: 2218: 2213: 2196: 2195: 2176: 2174: 2173: 2168: 2156: 2155: 2145: 2143: 2142: 2137: 2125: 2123: 2122: 2117: 2098: 2096: 2095: 2090: 2078: 2076: 2075: 2070: 2052: 2050: 2049: 2044: 2026: 2024: 2023: 2018: 2003: 2001: 2000: 1995: 1983: 1981: 1980: 1975: 1957: 1955: 1954: 1949: 1935: 1932: 1923: 1918: 1899: 1897: 1896: 1891: 1876: 1871: 1855: 1853: 1852: 1847: 1835: 1833: 1832: 1827: 1812: 1810: 1809: 1804: 1792: 1790: 1789: 1784: 1766: 1761: 1745: 1743: 1742: 1737: 1720: 1719: 1703: 1701: 1700: 1695: 1680: 1678: 1677: 1672: 1660: 1658: 1657: 1652: 1640: 1638: 1637: 1632: 1615: 1614: 1598: 1596: 1595: 1590: 1572: 1567: 1551: 1549: 1548: 1543: 1531: 1529: 1528: 1523: 1511: 1509: 1508: 1503: 1491: 1489: 1488: 1483: 1471: 1469: 1468: 1463: 1451: 1449: 1448: 1443: 1428: 1423: 1405: 1403: 1402: 1397: 1373: 1368: 1337: 1332: 1314: 1312: 1311: 1306: 1291: 1286: 1268: 1266: 1265: 1260: 1222: 1221: 1176: 1175: 1144: 1139: 1116: 1114: 1113: 1108: 1070: 1069: 1021: 1020: 989: 984: 966: 964: 963: 958: 937: 932: 913: 911: 910: 905: 894: 891: 882: 880: 879: 874: 854: 853: 837: 835: 834: 829: 809: 807: 806: 801: 799: 798: 775: 773: 772: 767: 765: 764: 756: 753: 744: 741: 721: 719: 718: 713: 701: 699: 698: 693: 676: 675: 656: 654: 653: 648: 636: 634: 633: 628: 616: 614: 613: 608: 606: 605: 589: 587: 586: 581: 569: 567: 566: 561: 546: 544: 543: 538: 523: 521: 520: 515: 504: 501: 492: 490: 489: 484: 472: 470: 469: 464: 452: 450: 449: 444: 433: 430: 421: 419: 418: 413: 398: 396: 395: 390: 378: 376: 375: 370: 350: 349: 327: 325: 324: 319: 305: 304: 288: 286: 285: 280: 265: 263: 262: 257: 245: 243: 242: 237: 225: 223: 222: 217: 205: 203: 202: 197: 185: 183: 182: 177: 165: 163: 162: 157: 145: 143: 142: 137: 125: 123: 122: 117: 97: 96: 77: 75: 74: 69: 21:Rosser's theorem 3841: 3840: 3836: 3835: 3834: 3832: 3831: 3830: 3816: 3815: 3805: 3779:10.2307/2269028 3728: 3704: 3701: 3700: 3699:does not prove 3684: 3681: 3680: 3664: 3661: 3660: 3641: 3638: 3637: 3621: 3618: 3617: 3601: 3598: 3597: 3581: 3578: 3577: 3545: 3540: 3531: 3528: 3527: 3511: 3508: 3507: 3476: 3464: 3459: 3453: 3450: 3449: 3433: 3430: 3429: 3410: 3407: 3406: 3390: 3387: 3386: 3369: 3364: 3358: 3355: 3354: 3335: 3332: 3331: 3330:does not prove 3315: 3312: 3311: 3295: 3292: 3291: 3275: 3272: 3271: 3255: 3252: 3251: 3232: 3229: 3228: 3212: 3209: 3208: 3176: 3171: 3165: 3162: 3161: 3145: 3142: 3141: 3125: 3122: 3121: 3105: 3102: 3101: 3066: 3061: 3055: 3052: 3051: 3035: 3032: 3031: 2996: 2991: 2985: 2982: 2981: 2965: 2962: 2961: 2945: 2942: 2941: 2925: 2922: 2921: 2905: 2902: 2901: 2885: 2882: 2881: 2865: 2862: 2861: 2829: 2824: 2818: 2815: 2814: 2798: 2795: 2794: 2778: 2775: 2774: 2743: 2725: 2721: 2716: 2713: 2712: 2696: 2693: 2692: 2676: 2673: 2672: 2656: 2653: 2652: 2636: 2633: 2632: 2597: 2593: 2591: 2588: 2587: 2571: 2568: 2567: 2532: 2527: 2521: 2518: 2517: 2501: 2498: 2497: 2462: 2457: 2451: 2448: 2447: 2431: 2428: 2427: 2411: 2408: 2407: 2385: 2382: 2381: 2380:does not prove 2365: 2362: 2361: 2344: 2341: 2340: 2339:does not prove 2324: 2321: 2320: 2301: 2298: 2297: 2281: 2278: 2277: 2274: 2252: 2249: 2248: 2247: 2244:Rosser sentence 2227: 2224: 2223: 2191: 2187: 2182: 2179: 2178: 2162: 2159: 2158: 2154: 2149: 2148: 2147: 2131: 2128: 2127: 2111: 2108: 2107: 2084: 2081: 2080: 2058: 2055: 2054: 2032: 2029: 2028: 2009: 2006: 2005: 1989: 1986: 1985: 1963: 1960: 1959: 1931: 1919: 1914: 1905: 1902: 1901: 1872: 1867: 1861: 1858: 1857: 1841: 1838: 1837: 1821: 1818: 1817: 1798: 1795: 1794: 1762: 1757: 1751: 1748: 1747: 1715: 1711: 1709: 1706: 1705: 1686: 1683: 1682: 1666: 1663: 1662: 1646: 1643: 1642: 1610: 1606: 1604: 1601: 1600: 1568: 1563: 1557: 1554: 1553: 1537: 1534: 1533: 1517: 1514: 1513: 1497: 1494: 1493: 1477: 1474: 1473: 1457: 1454: 1453: 1424: 1419: 1413: 1410: 1409: 1369: 1364: 1333: 1328: 1322: 1319: 1318: 1287: 1282: 1276: 1273: 1272: 1217: 1213: 1171: 1167: 1140: 1135: 1126: 1123: 1122: 1065: 1061: 1016: 1012: 985: 980: 974: 971: 970: 967:is defined as: 933: 928: 922: 919: 918: 890: 888: 885: 884: 849: 845: 843: 840: 839: 823: 820: 819: 816: 794: 790: 785: 782: 781: 757: 752: 751: 740: 732: 729: 728: 707: 704: 703: 671: 667: 662: 659: 658: 642: 639: 638: 622: 619: 618: 601: 597: 595: 592: 591: 575: 572: 571: 555: 552: 551: 529: 526: 525: 500: 498: 495: 494: 478: 475: 474: 458: 455: 454: 429: 427: 424: 423: 407: 404: 403: 384: 381: 380: 345: 341: 333: 330: 329: 300: 296: 294: 291: 290: 271: 268: 267: 251: 248: 247: 231: 228: 227: 211: 208: 207: 191: 188: 187: 171: 168: 167: 151: 148: 147: 131: 128: 127: 92: 88: 86: 83: 82: 63: 60: 59: 56: 24: 17: 12: 11: 5: 3839: 3829: 3828: 3814: 3813: 3804: 3803:External links 3801: 3800: 3799: 3756: 3738: 3727: 3724: 3711: 3708: 3688: 3668: 3648: 3645: 3625: 3605: 3585: 3565: 3562: 3559: 3556: 3553: 3548: 3543: 3539: 3535: 3515: 3495: 3492: 3489: 3486: 3483: 3475: 3472: 3467: 3462: 3458: 3437: 3417: 3414: 3394: 3372: 3367: 3363: 3339: 3319: 3299: 3279: 3259: 3239: 3236: 3216: 3196: 3193: 3190: 3187: 3184: 3179: 3174: 3170: 3149: 3129: 3109: 3086: 3083: 3080: 3077: 3074: 3069: 3064: 3060: 3039: 3019: 3016: 3013: 3010: 3007: 3004: 2999: 2994: 2990: 2969: 2949: 2929: 2909: 2889: 2869: 2857:in that case. 2846: 2843: 2840: 2837: 2832: 2827: 2823: 2802: 2782: 2759: 2756: 2753: 2750: 2742: 2739: 2736: 2733: 2728: 2724: 2720: 2700: 2680: 2660: 2640: 2620: 2617: 2614: 2611: 2608: 2605: 2600: 2596: 2575: 2555: 2552: 2549: 2546: 2543: 2540: 2535: 2530: 2526: 2505: 2485: 2482: 2479: 2476: 2473: 2470: 2465: 2460: 2456: 2435: 2415: 2404: 2403: 2392: 2389: 2369: 2359: 2348: 2328: 2305: 2285: 2273: 2270: 2256: 2246:of the theory 2231: 2222:. The formula 2211: 2208: 2205: 2202: 2199: 2194: 2190: 2186: 2166: 2150: 2135: 2115: 2104:diagonal lemma 2088: 2068: 2065: 2062: 2042: 2039: 2036: 2016: 2013: 1993: 1973: 1970: 1967: 1947: 1944: 1941: 1938: 1930: 1927: 1922: 1917: 1913: 1909: 1889: 1886: 1883: 1880: 1875: 1870: 1866: 1845: 1825: 1802: 1782: 1779: 1776: 1773: 1770: 1765: 1760: 1756: 1735: 1732: 1729: 1726: 1723: 1718: 1714: 1693: 1690: 1670: 1650: 1630: 1627: 1624: 1621: 1618: 1613: 1609: 1588: 1585: 1582: 1579: 1576: 1571: 1566: 1562: 1541: 1521: 1501: 1481: 1461: 1441: 1438: 1435: 1432: 1427: 1422: 1418: 1395: 1392: 1389: 1386: 1383: 1380: 1377: 1372: 1367: 1363: 1359: 1356: 1353: 1350: 1347: 1344: 1341: 1336: 1331: 1327: 1304: 1301: 1298: 1295: 1290: 1285: 1281: 1258: 1255: 1252: 1249: 1246: 1243: 1240: 1237: 1234: 1231: 1228: 1225: 1220: 1216: 1212: 1209: 1206: 1203: 1200: 1197: 1194: 1191: 1188: 1185: 1182: 1179: 1174: 1170: 1166: 1163: 1160: 1157: 1154: 1151: 1148: 1143: 1138: 1134: 1130: 1106: 1103: 1100: 1097: 1094: 1091: 1088: 1085: 1082: 1079: 1076: 1073: 1068: 1064: 1060: 1057: 1054: 1051: 1048: 1045: 1042: 1039: 1036: 1033: 1030: 1027: 1024: 1019: 1015: 1011: 1008: 1005: 1002: 999: 996: 993: 988: 983: 979: 956: 953: 950: 947: 944: 941: 936: 931: 927: 903: 900: 897: 872: 869: 866: 863: 860: 857: 852: 848: 827: 815: 812: 797: 793: 789: 763: 760: 750: 747: 739: 736: 711: 691: 688: 685: 682: 679: 674: 670: 666: 646: 626: 604: 600: 579: 559: 536: 533: 513: 510: 507: 482: 462: 442: 439: 436: 411: 388: 368: 365: 362: 359: 356: 353: 348: 344: 340: 337: 328:is defined as 317: 314: 311: 308: 303: 299: 278: 275: 255: 235: 215: 195: 175: 155: 135: 115: 112: 109: 106: 103: 100: 95: 91: 67: 55: 52: 32:Rosser's trick 15: 9: 6: 4: 3: 2: 3838: 3827: 3824: 3823: 3821: 3811: 3807: 3806: 3796: 3792: 3788: 3784: 3780: 3776: 3772: 3768: 3767: 3762: 3757: 3755: 3754:0-444-86388-5 3751: 3747: 3743: 3739: 3737: 3733: 3730: 3729: 3723: 3709: 3686: 3666: 3646: 3623: 3603: 3583: 3560: 3551: 3546: 3541: 3537: 3513: 3487: 3470: 3465: 3460: 3456: 3435: 3415: 3392: 3370: 3365: 3361: 3351: 3337: 3317: 3297: 3277: 3257: 3237: 3214: 3191: 3182: 3177: 3172: 3168: 3147: 3127: 3107: 3098: 3081: 3072: 3067: 3062: 3058: 3037: 3014: 3011: 3008: 3002: 2997: 2992: 2988: 2967: 2947: 2927: 2907: 2887: 2867: 2858: 2841: 2835: 2830: 2825: 2821: 2800: 2780: 2771: 2751: 2740: 2737: 2731: 2726: 2722: 2698: 2678: 2658: 2651:smaller than 2638: 2615: 2612: 2609: 2603: 2598: 2594: 2573: 2550: 2547: 2544: 2538: 2533: 2528: 2524: 2503: 2480: 2477: 2474: 2468: 2463: 2458: 2454: 2433: 2426:and a number 2413: 2390: 2367: 2360: 2346: 2326: 2319: 2318: 2317: 2303: 2283: 2269: 2254: 2245: 2229: 2206: 2197: 2192: 2188: 2164: 2153: 2133: 2113: 2105: 2100: 2086: 2066: 2063: 2060: 2040: 2037: 2034: 2014: 1991: 1971: 1968: 1965: 1939: 1925: 1920: 1915: 1911: 1884: 1878: 1873: 1868: 1864: 1843: 1823: 1814: 1800: 1777: 1768: 1763: 1758: 1754: 1730: 1721: 1716: 1712: 1691: 1668: 1648: 1625: 1616: 1611: 1607: 1583: 1574: 1569: 1564: 1560: 1539: 1519: 1499: 1479: 1459: 1436: 1430: 1425: 1420: 1416: 1406: 1393: 1387: 1384: 1381: 1375: 1370: 1365: 1361: 1357: 1351: 1345: 1339: 1334: 1329: 1325: 1316: 1299: 1293: 1288: 1283: 1279: 1269: 1256: 1244: 1238: 1235: 1232: 1229: 1223: 1218: 1214: 1207: 1204: 1201: 1189: 1186: 1183: 1177: 1172: 1168: 1164: 1158: 1155: 1152: 1146: 1141: 1136: 1132: 1120: 1117: 1104: 1092: 1086: 1083: 1080: 1077: 1071: 1066: 1062: 1055: 1052: 1049: 1040: 1034: 1031: 1028: 1022: 1017: 1013: 1009: 1003: 1000: 997: 991: 986: 981: 977: 968: 951: 948: 945: 939: 934: 929: 925: 915: 898: 867: 864: 861: 855: 850: 846: 825: 811: 795: 791: 779: 761: 758: 745: 737: 734: 726: 709: 686: 677: 672: 668: 644: 624: 602: 598: 577: 570:is a formula 557: 548: 534: 508: 480: 460: 437: 409: 400: 386: 363: 360: 357: 351: 346: 342: 338: 312: 306: 301: 297: 276: 253: 233: 213: 193: 173: 153: 133: 110: 107: 104: 98: 93: 89: 79: 65: 51: 47: 45: 41: 37: 33: 29: 22: 3773:(3): 87–91. 3770: 3764: 3741: 3735: 3596:also proves 3352: 3227:also proves 3099: 2980:. Therefore 2859: 2813:also proves 2772: 2496:holds, then 2405: 2275: 2243: 2151: 2101: 1815: 1552:the formula 1408:Informally, 1407: 1317: 1270: 1121: 1118: 969: 916: 817: 778:Peano axioms 725:ω-consistent 617:, such that 549: 401: 80: 57: 48: 31: 25: 3746:Jon Barwise 2079:. (In fact 1704:. However, 266:is denoted 3726:References 2102:Using the 54:Background 3732:Mendelson 3710:ρ 3707:¬ 3647:ρ 3644:¬ 3604:ρ 3561:ρ 3558:# 3552:⁡ 3534:¬ 3488:ρ 3482:# 3471:⁡ 3416:ρ 3413:¬ 3385:. Assume 3338:ρ 3278:ρ 3238:ρ 3235:¬ 3192:ρ 3189:# 3183:⁡ 3128:ρ 3082:ϕ 3079:# 3073:⁡ 3003:⁡ 2948:ϕ 2888:ϕ 2836:⁡ 2732:⁡ 2719:¬ 2604:⁡ 2539:⁡ 2469:⁡ 2391:ρ 2388:¬ 2347:ρ 2304:ρ 2230:ρ 2207:ρ 2204:# 2198:⁡ 2185:¬ 2165:ρ 2114:ρ 2015:ϕ 2012:¬ 1992:ϕ 1940:ϕ 1926:⁡ 1908:¬ 1885:ϕ 1879:⁡ 1844:ϕ 1778:ϕ 1775:# 1769:⁡ 1731:ϕ 1728:# 1722:⁡ 1692:ϕ 1689:¬ 1649:ϕ 1626:ϕ 1623:# 1617:⁡ 1584:ϕ 1581:# 1575:⁡ 1540:ϕ 1431:⁡ 1376:⁡ 1355:∃ 1352:≡ 1340:⁡ 1294:⁡ 1239:⁡ 1224:⁡ 1205:≤ 1199:∃ 1196:→ 1178:⁡ 1165:≡ 1147:⁡ 1129:¬ 1087:⁡ 1072:⁡ 1053:≤ 1047:∃ 1044:¬ 1041:∧ 1023:⁡ 1010:≡ 992:⁡ 940:⁡ 856:⁡ 788:¬ 780:, proves 749:¬ 687:ϕ 684:# 678:⁡ 665:¬ 645:ϕ 578:ϕ 535:ϕ 532:¬ 481:ϕ 352:⁡ 336:∃ 307:⁡ 277:ϕ 274:# 254:ϕ 99:⁡ 3820:Category 3795:36635388 3734:(1977), 1900:implies 3787:2269028 3636:proves 3576:. Thus 3526:proves 3448:proves 3405:proves 3270:proves 3207:. Thus 3160:proves 3120:proves 3050:proves 2711:proves 2586:proves 2516:proves 2242:is the 2177: â†” 657: â†” 637:proves 3793:  3785:  3752:  2157:(#ρ). 2106:, let 838:, let 3791:S2CID 3783:JSTOR 3362:Proof 2989:Proof 2723:Proof 2595:Proof 2525:Proof 2455:Proof 2446:, if 1362:Proof 1215:Proof 1169:Proof 1133:Proof 1063:Proof 1014:Proof 978:Proof 926:Proof 847:Proof 493:then 343:Proof 90:Proof 3750:ISBN 3538:Pvbl 3457:Pvbl 3169:Pvbl 3059:Pvbl 2822:Pvbl 2745:(neg 2276:Let 2189:Pvbl 2064:< 2053:and 2038:< 2004:and 1912:Pvbl 1865:Pvbl 1755:Pvbl 1746:and 1713:Pvbl 1608:Pvbl 1561:Pvbl 1417:Pvbl 1326:Pvbl 1280:Pvbl 883:and 669:Pvbl 298:Pvbl 3775:doi 3478:neg 2960:in 1933:neg 1236:neg 1084:neg 892:neg 502:neg 431:neg 26:In 3822:: 3789:. 3781:. 3769:. 3763:. 3744:, 3722:. 3350:. 3097:. 2691:, 1856:, 1813:. 1315:: 742:PA 399:. 30:, 3797:. 3777:: 3771:1 3687:T 3667:T 3624:T 3584:T 3564:) 3555:( 3547:R 3542:T 3514:T 3494:) 3491:) 3485:( 3474:( 3466:R 3461:T 3436:T 3393:T 3371:R 3366:T 3318:T 3298:T 3258:T 3215:T 3195:) 3186:( 3178:R 3173:T 3148:T 3108:T 3085:) 3076:( 3068:R 3063:T 3038:T 3018:) 3015:y 3012:, 3009:e 3006:( 2998:R 2993:T 2968:T 2928:T 2908:e 2868:T 2845:) 2842:y 2839:( 2831:R 2826:T 2801:T 2781:T 2758:) 2755:) 2752:y 2749:( 2741:, 2738:z 2735:( 2727:T 2699:T 2679:z 2659:e 2639:z 2619:) 2616:y 2613:, 2610:e 2607:( 2599:T 2574:T 2554:) 2551:y 2548:, 2545:e 2542:( 2534:R 2529:T 2504:T 2484:) 2481:y 2478:, 2475:e 2472:( 2464:R 2459:T 2434:e 2414:y 2368:T 2327:T 2284:T 2267:. 2255:T 2210:) 2201:( 2193:T 2152:T 2134:T 2087:T 2067:n 2061:m 2041:m 2035:n 1972:m 1969:, 1966:n 1946:) 1943:) 1937:( 1929:( 1921:R 1916:T 1888:) 1882:( 1874:R 1869:T 1824:T 1801:T 1781:) 1772:( 1764:R 1759:T 1734:) 1725:( 1717:T 1669:T 1629:) 1620:( 1612:T 1587:) 1578:( 1570:R 1565:T 1520:T 1500:y 1480:x 1460:y 1440:) 1437:y 1434:( 1426:R 1421:T 1394:. 1391:) 1388:y 1385:, 1382:x 1379:( 1371:R 1366:T 1358:x 1349:) 1346:y 1343:( 1335:R 1330:T 1303:) 1300:y 1297:( 1289:R 1284:T 1257:. 1254:] 1251:) 1248:) 1245:y 1242:( 1233:, 1230:z 1227:( 1219:T 1211:[ 1208:x 1202:z 1193:) 1190:y 1187:, 1184:x 1181:( 1173:T 1162:) 1159:y 1156:, 1153:x 1150:( 1142:R 1137:T 1105:, 1102:] 1099:) 1096:) 1093:y 1090:( 1081:, 1078:z 1075:( 1067:T 1059:[ 1056:x 1050:z 1038:) 1035:y 1032:, 1029:x 1026:( 1018:T 1007:) 1004:y 1001:, 998:x 995:( 987:R 982:T 955:) 952:y 949:, 946:x 943:( 935:R 930:T 902:) 899:x 896:( 871:) 868:y 865:, 862:x 859:( 851:T 826:T 796:T 792:G 762:A 759:P 754:G 746:+ 738:= 735:T 710:T 690:) 681:( 673:T 625:T 603:T 599:G 558:T 512:) 509:y 506:( 461:y 441:) 438:y 435:( 410:T 387:T 367:) 364:y 361:, 358:x 355:( 347:T 339:x 316:) 313:y 310:( 302:T 234:y 214:y 194:y 174:T 154:x 134:y 114:) 111:y 108:, 105:x 102:( 94:T 66:T 23:.

Index

Rosser's theorem
mathematical logic
Gödel's incompleteness theorems
ω-consistent
J. Barkley Rosser
ω-consistent
Peano axioms
diagonal lemma
Mendelson
Jon Barwise
ISBN
0-444-86388-5
"Extensions of some theorems of Gödel and Church"
Journal of Symbolic Logic
doi
10.2307/2269028
JSTOR
2269028
S2CID
36635388
Computability and Incompleteness
Category
Mathematical logic

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