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Proof by infinite descent

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4553: 1271: 972: 47:, it would necessarily imply that a second solution existed, which was related to one or more 'smaller' natural numbers. This in turn would imply a third solution related to smaller natural numbers, implying a fourth solution, therefore a fifth solution, and so on. However, there cannot be an infinity of ever-smaller natural numbers, and therefore by 1266:{\displaystyle {\begin{aligned}{\sqrt {k}}&={\frac {m}{n}}\\&={\frac {m\left({\sqrt {k}}-q\right)}{n\left({\sqrt {k}}-q\right)}}\\&={\frac {m{\sqrt {k}}-mq}{n{\sqrt {k}}-nq}}\\&={\frac {\left(n{\sqrt {k}}\right){\sqrt {k}}-mq}{n\left({\frac {m}{n}}\right)-nq}}\\&={\frac {nk-mq}{m-nq}}\end{aligned}}} 381:
of Metapontum is often mentioned. For a while, the Pythagoreans treated as an official secret the discovery that the square root of two is irrational, and, according to legend, Hippasus was murdered for divulging it. The square root of two is occasionally called "Pythagoras' number" or "Pythagoras'
2224:
In any of these cases, one Pythagorean triangle with two sides each of which is a square or twice a square has led to a smaller one, which in turn would lead to a smaller one, etc.; since such a sequence cannot go on infinitely, the original premise that such a triangle exists must be wrong.
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used to show that a statement cannot possibly hold for any number, by showing that if the statement were to hold for a number, then the same would be true for a smaller number, leading to an infinite descent and ultimately a contradiction. It is a method which relies on the
62:—can then be inferred. Once there, one would try to prove that if a smallest solution exists, then it must imply the existence of a smaller solution (in some sense), which again proves that the existence of any solution would lead to a contradiction. 1490:
Suppose there exists such a Pythagorean triangle. Then it can be scaled down to give a primitive (i.e., with no common factors other than 1) Pythagorean triangle with the same property. Primitive Pythagorean triangles' sides can be written as
1483:, and the historical proofs of the latter proceeded by more broadly proving the former using infinite descent. The following more recent proof demonstrates both of these impossibilities by proving still more broadly that a 977: 232:
roughly doubles the length of the numbers required to write it (as number of digits), so that "halving" a point gives a rational with smaller terms. Since the terms are positive, they cannot decrease forever.
819: 461: 529: 202:). In this way Fermat was able to show the non-existence of solutions in many cases of Diophantine equations of classical interest (for example, the problem of four perfect squares in 684: 192: 2342: 2285: 2397: 1477: 1424: 199: 138: 2932: 1572: 2218: 1897: 1617: 731: 576: 1716: 2124: 2041: 1977: 3607: 832:
could be written as a rational number, then it could always be written as a rational number with smaller parts, which itself could be written with yet-smaller parts,
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An alternative way to express this is to assume one or more solutions or examples exists, from which a smallest solution or example—a
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of the twentieth century, the infinite descent method was taken up again, and pushed to a point where it connected with the main thrust of
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is a square or twice a square. There are three cases, depending on which two sides are postulated to each be a square or twice a square:
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that have the same ratio. But infinite descent on the natural numbers is impossible, so this disproves the original assumption that
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discovered that the diagonal of a square is incommensurable with its side, or in modern language, that the square root of two is
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cannot have non-trivial solutions, since non-trivial solutions would give Pythagorean triangles with two sides being squares.
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were rational, no "smallest" representation as a fraction could exist, as any attempt to find a "smallest" representation
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cannot have any two of its sides each either a square or twice a square, since there is no smallest such triangle:
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Typically, one shows that if a solution to a problem existed, which in some sense was related to one or more
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proves that every composite integer is divided (in Euclid's terminology "measured") by some prime number.
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presented another geometric proof by infinite descent that may be more accessible). The following is an
4552: 2349: 1429: 1376: 1289:)—which is positive but less than 1—and then simplified independently. So, the resulting products, say 90: 4399: 4361: 4238: 4042: 3882: 3806: 3784: 3612: 3570: 3469: 3436: 3300: 3088: 2999: 2742: 2561: 2154:) each of which is a square or twice a square, with a smaller hypotenuse than the original triangle ( 1484: 84: 66: 51:, the original premise—that any solution exists—is incorrect: its correctness produces a 37: 1528: 377:. Little is known with certainty about the time or circumstances of this discovery, but the name of 4528: 4419: 4404: 4384: 4341: 4228: 4178: 4104: 4049: 3986: 3779: 3774: 3722: 3490: 3479: 3151: 3051: 2979: 2970: 2966: 2901: 2896: 2177: 1856: 1576: 690: 535: 2471: 1694: 4557: 4326: 4289: 4274: 4267: 4250: 4036: 3902: 3828: 3811: 3764: 3577: 3486: 3320: 3305: 3265: 3217: 3202: 3190: 3146: 3121: 2891: 2840: 2720: 2105: 2022: 1958: 402: 210: 195: 4054: 3510: 4492: 4299: 4109: 4099: 3991: 3872: 3707: 3683: 3464: 3448: 3353: 3330: 3207: 3176: 3141: 3036: 2871: 2565: 2445: 594: 374: 362: 320: 307:) is finite, which is certainly a necessary condition for the finite generation of the group 209:
In some cases, to the modern eye, his "method of infinite descent" is an exploitation of the
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had to make more explicit the way of quantifying the size of a solution, by means of a
218: 214: 44: 4571: 4446: 4124: 3631: 3416: 3406: 3376: 3361: 3031: 2799: 2553: 2418: 390: 366: 284: 242: 149: 52: 365:(i.e. cannot be expressed as a fraction of two whole numbers) was discovered by the 4346: 4193: 4094: 4086: 3966: 3914: 3823: 3759: 3742: 3673: 3532: 3391: 3093: 2876: 2649: 834: 586: 87:. Two typical examples are showing the non-solvability of the Diophantine equation 2439: 2409:= 4 case of Fermat's Theorem, see the articles by Grant and Perella and Barbara. 4456: 4336: 3515: 3505: 3452: 3136: 3056: 3041: 2921: 2866: 850: 20: 3386: 3241: 3212: 3018: 2803: 2793: 2456:
a special case of proof by contradiction called the method of infinite descent
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would imply that a smaller one existed, which is a similar contradiction.)
853:, which can be either rational or irrational, the only option left is for 4523: 4321: 3769: 3474: 3068: 2789: 2499:"Fermat's Method of Infinite Descent | Brilliant Math & Science Wiki" 2019:) each of which is a square or twice a square, and a smaller hypotenuse ( 378: 4119: 2911: 2724: 1627: 406: 394: 254: 1276:
The numerator and denominator were each multiplied by the expression (
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Number Theory: An approach through history from Hammurapi to Legendre
80: 73: 2716: 2614: 27:, also known as Fermat's method of descent, is a particular kind of 2755:
Grant, Mike, and Perella, Malcolm, "Descending to the irrational",
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Sagher, Yoram (February 1988), "What Pythagoras could have done",
224:. The context is of a hypothetical non-trivial rational point on 2813: 2615:"The discovery of incommensurability by Hippasus of Metapontum" 331:
was at the start of what later became a very extensive theory.
2601: 814:{\displaystyle {\frac {p}{q}}={\frac {2r}{2s}}={\frac {r}{s}}} 65:
The earliest uses of the method of infinite descent appear in
36:, and is often used to show that a given equation, such as a 908:
is not an integer, but is rational and can be expressed as
319:, one must do calculations in what later was recognised as 72:. A typical example is Proposition 31 of Book 7, in which 1426:
in integers is sufficient to show the non-solvability of
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are both squares. But then the right triangle with legs
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respectively. Therefore, no matter what natural numbers
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also would have integer sides including a square leg (
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For other similar proofs by infinite descent for the
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Fermat's right triangle theorem § Fermat's proof
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The integer right triangle with legs 1891: 1845: 1818: 1791: 1764: 1737: 1710: 1611: 1566: 1518: 1471: 1418: 1347:could be expressed as a ratio of natural numbers. 1265: 813: 725: 678: 570: 523: 455: 186: 132: 2768:Barbara, Roy, "Fermat's last theorem in the case 840:this is impossible in the set of natural numbers 257:, that the rational points on an elliptic curve 16:Mathematical proof technique using contradiction 2825: 1297:, are themselves integers, and are less than 265:, used an infinite descent argument based on 8: 2441:The Moment of Proof: Mathematical Epiphanies 1662:is a square or twice a square, then each of 83:, who coined the term and often used it for 3651: 3246: 3014: 2832: 2818: 2810: 2650:"Square root of 2 is irrational (Proof 8)" 456:{\displaystyle {\sqrt {2}}={\frac {p}{q}}} 2383: 2370: 2357: 2351: 2325: 2312: 2299: 2293: 2268: 2255: 2242: 2236: 2204: 2191: 2179: 2159: 2131: 2109: 2107: 2087: 2049: 2026: 2024: 2004: 1984: 1962: 1960: 1940: 1920: 1883: 1870: 1858: 1837: 1831: 1810: 1804: 1783: 1777: 1756: 1750: 1729: 1723: 1698: 1696: 1603: 1590: 1578: 1555: 1542: 1530: 1496: 1463: 1450: 1437: 1431: 1410: 1397: 1384: 1378: 1224: 1188: 1163: 1151: 1140: 1111: 1090: 1084: 1053: 1025: 1014: 994: 980: 976: 974: 801: 778: 765: 763: 714: 698: 692: 667: 651: 629: 620: 559: 546: 537: 524:{\displaystyle 2={\frac {p^{2}}{q^{2}}},} 510: 500: 494: 486: 443: 433: 431: 383: 168: 157: 124: 111: 98: 92: 1826:), and would have a smaller hypotenuse ( 1479:in integers, which is a special case of 2444:. Oxford University Press. p. 43. 2430: 1658:can be twice a square. Furthermore, if 679:{\displaystyle 2q^{2}=(2r)^{2}=4r^{2},} 142:Fermat's theorem on sums of two squares 79:The method was much later developed by 1322:, there exist smaller natural numbers 7: 2520: 2518: 2493: 2491: 2466: 2464: 863:(Alternatively, this proves that if 187:{\displaystyle p\equiv 1{\pmod {4}}} 176: 2337:{\displaystyle r^{4}+s^{2}=t^{4},} 2280:{\displaystyle r^{2}+s^{4}=t^{4},} 14: 2736:Dolan, Stan, "Fermat's method of 2392:{\displaystyle r^{4}+s^{4}=t^{2}} 1650:are each odd means that neither 1472:{\displaystyle q^{4}+s^{4}=t^{4}} 1419:{\displaystyle r^{2}+s^{4}=t^{4}} 940:be the largest integer less than 276:To extend this to the case of an 148:can be expressed as a sum of two 144:, which states that an odd prime 133:{\displaystyle r^{2}+s^{4}=t^{4}} 4551: 2800:Example of Fermat's last theorem 2673:Conrad, Keith (August 6, 2008). 2228:This implies that the equations 327:in the tradition of Fermat. The 263:finitely-generated abelian group 736:which shows that 2 must divide 169: 2617:, Annals of Mathematics, 1945. 1567:{\displaystyle y=a^{2}-b^{2},} 648: 638: 423:. Then it could be written as 180: 170: 1: 4512:History of mathematical logic 2704:American Mathematical Monthly 2213:{\displaystyle z=a^{2}+b^{2}} 1892:{\displaystyle z=a^{2}+b^{2}} 1612:{\displaystyle z=a^{2}+b^{2}} 726:{\displaystyle q^{2}=2r^{2},} 571:{\displaystyle 2q^{2}=p^{2},} 213:of the doubling function for 4437:Primitive recursive function 2527:"Fermat's Method of Descent" 1711:{\displaystyle {\sqrt {yz}}} 1642:both odd. The property that 2759:83, July 1999, pp. 263–267. 2604:, Nrich.org, November 2004. 2119:{\displaystyle {\sqrt {y}}} 2036:{\displaystyle {\sqrt {z}}} 1979:also would have two sides ( 1972:{\displaystyle {\sqrt {z}}} 1799:) and a square hypotenuse ( 478:. Then squaring would give 409:proof along similar lines: 253:. The structural result of 4604: 3501:Schröder–Bernstein theorem 3228:Monadic predicate calculus 2887:Foundations of mathematics 2472:"What Is Infinite Descent" 2438:Benson, Donald C. (2000). 1366: 4547: 4534:Philosophy of mathematics 4483:Automated theorem proving 3654: 3608:Von Neumann–Bernays–Gödel 3249: 2602:"The Dangerous Ratio ..." 2585:"The Pythagorean Theorem" 466:for two natural numbers, 200:proof by infinite descent 4588:Mathematical terminology 2638:, Copernicus, p. 25 315:) of rational points of 4184:Self-verifying theories 4005:Tarski's axiomatization 2956:Tarski's undefinability 2951:incompleteness theorems 2776:91, July 2007, 260–262. 2746:95, July 2011, 269–271. 1373:The non-solvability of 891:if it is not an integer 384:Conway & Guy (1996) 382:Constant", for example 247:algebraic number theory 34:well-ordering principle 4558:Mathematics portal 4169:Proof of impossibility 3817:propositional variable 3127:Propositional calculus 2682:kconrad.math.uconn.edu 2587:, Dept. of Math. Ed., 2393: 2338: 2281: 2214: 2168: 2146:would have two sides ( 2140: 2120: 2096: 2058: 2037: 2013: 1993: 1973: 1949: 1929: 1893: 1847: 1820: 1793: 1766: 1739: 1712: 1613: 1568: 1520: 1519:{\displaystyle x=2ab,} 1473: 1420: 1267: 815: 727: 680: 589:, it must also divide 572: 525: 457: 228:. Doubling a point on 204:arithmetic progression 188: 134: 60:minimal counterexample 49:mathematical induction 29:proof by contradiction 4578:Diophantine equations 4427:Kolmogorov complexity 4380:Computably enumerable 4280:Model complete theory 4072:Principia Mathematica 3132:Propositional formula 2961:Banach–Tarski paradox 2589:University of Georgia 2583:Stephanie J. Morris, 2394: 2339: 2282: 2215: 2169: 2141: 2121: 2097: 2059: 2038: 2014: 1994: 1974: 1950: 1930: 1894: 1848: 1846:{\displaystyle a^{2}} 1821: 1819:{\displaystyle a^{2}} 1794: 1792:{\displaystyle b^{2}} 1767: 1765:{\displaystyle a^{2}} 1740: 1738:{\displaystyle b^{2}} 1713: 1614: 1569: 1521: 1481:Fermat's Last Theorem 1474: 1421: 1268: 895:For positive integer 816: 728: 681: 573: 526: 458: 401:by infinite descent ( 189: 135: 85:Diophantine equations 4375:Church–Turing thesis 4362:Computability theory 3571:continuum hypothesis 3089:Square of opposition 2947:Gödel's completeness 2774:Mathematical Gazette 2757:Mathematical Gazette 2743:Mathematical Gazette 2654:www.cut-the-knot.org 2476:www.cut-the-knot.org 2350: 2292: 2235: 2178: 2158: 2130: 2106: 2086: 2048: 2023: 2003: 1983: 1959: 1939: 1919: 1857: 1830: 1803: 1776: 1749: 1722: 1695: 1577: 1529: 1495: 1485:Pythagorean triangle 1430: 1377: 1363:and its permutations 1313:are used to express 973: 928:for natural numbers 762: 691: 619: 536: 485: 430: 335:Application examples 329:Mordell–Weil theorem 156: 91: 40:, has no solutions. 38:Diophantine equation 4583:Mathematical proofs 4529:Mathematical object 4420:P versus NP problem 4385:Computable function 4179:Reverse mathematics 4105:Logical consequence 3982:primitive recursive 3977:elementary function 3750:Free/bound variable 3603:Tarski–Grothendieck 3122:Logical connectives 3052:Logical equivalence 2902:Logical consequence 2636:The Book of Numbers 1351:Non-solvability of 605:, for some integer 350:The proof that the 273:in Fermat's style. 4327:Transfer principle 4290:Semantics of logic 4275:Categorical theory 4251:Non-standard model 3765:Logical connective 2892:Information theory 2841:Mathematical logic 2675:"Infinite Descent" 2564:, pp. 75–79, 2389: 2334: 2277: 2210: 2164: 2136: 2116: 2092: 2054: 2033: 2009: 1989: 1969: 1945: 1925: 1889: 1843: 1816: 1789: 1762: 1735: 1708: 1609: 1564: 1516: 1469: 1416: 1263: 1261: 860:to be irrational. 811: 723: 676: 568: 521: 453: 403:John Horton Conway 196:Modular arithmetic 184: 130: 4565: 4564: 4497:Abstract category 4300:Theories of truth 4110:Rule of inference 4100:Natural deduction 4081: 4080: 3626: 3625: 3331:Cartesian product 3236: 3235: 3142:Many-valued logic 3117:Boolean functions 3000:Russell's paradox 2975:diagonal argument 2872:First-order logic 2772: = 4", 2525:Donaldson, Neil. 2451:978-0-19-513919-8 2167:{\displaystyle a} 2139:{\displaystyle a} 2114: 2095:{\displaystyle b} 2057:{\displaystyle z} 2031: 2012:{\displaystyle b} 1992:{\displaystyle a} 1967: 1948:{\displaystyle b} 1928:{\displaystyle a} 1706: 1257: 1212: 1196: 1168: 1156: 1128: 1116: 1095: 1072: 1058: 1030: 1002: 985: 882:Irrationality of 809: 796: 773: 748:for some integer 585:. Because 2 is a 581:so 2 must divide 516: 451: 438: 340:Irrationality of 321:Galois cohomology 249:and the study of 4595: 4556: 4555: 4507:History of logic 4502:Category of sets 4395:Decision problem 4174:Ordinal analysis 4115:Sequent calculus 4013:Boolean algebras 3953: 3952: 3927: 3898:logical/constant 3652: 3638: 3561:Zermelo–Fraenkel 3312:Set operations: 3247: 3184: 3015: 2995:Löwenheim–Skolem 2882:Formal semantics 2834: 2827: 2820: 2811: 2790:Infinite descent 2777: 2766: 2760: 2753: 2747: 2738:descente infinie 2734: 2728: 2727: 2698: 2692: 2691: 2689: 2688: 2679: 2670: 2664: 2663: 2661: 2660: 2646: 2640: 2639: 2624: 2618: 2613:Kurt von Fritz, 2611: 2605: 2598: 2592: 2581: 2575: 2574: 2550: 2544: 2543: 2541: 2540: 2531: 2522: 2513: 2512: 2510: 2509: 2495: 2486: 2485: 2483: 2482: 2468: 2459: 2458: 2435: 2398: 2396: 2395: 2390: 2388: 2387: 2375: 2374: 2362: 2361: 2343: 2341: 2340: 2335: 2330: 2329: 2317: 2316: 2304: 2303: 2286: 2284: 2283: 2278: 2273: 2272: 2260: 2259: 2247: 2246: 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1211: 1201: 1197: 1189: 1179: 1169: 1164: 1162: 1158: 1157: 1152: 1141: 1133: 1129: 1127: 1117: 1112: 1106: 1096: 1091: 1085: 1077: 1073: 1071: 1070: 1066: 1059: 1054: 1043: 1042: 1038: 1031: 1026: 1015: 1007: 1003: 995: 986: 981: 965: 964: 948: 947: 927: 925: 924: 919: 916: 907: 906: 890: 889: 869: 868: 859: 858: 848: 847: 831: 830: 820: 818: 817: 812: 810: 802: 797: 795: 787: 779: 774: 766: 732: 730: 729: 724: 719: 718: 703: 702: 685: 683: 682: 677: 672: 671: 656: 655: 634: 633: 577: 575: 574: 569: 564: 563: 551: 550: 530: 528: 527: 522: 517: 515: 514: 505: 504: 495: 477: 471: 462: 460: 459: 454: 452: 444: 439: 434: 418: 417: 360: 359: 352:square root of 2 346: 345: 193: 191: 190: 185: 183: 139: 137: 136: 131: 129: 128: 116: 115: 103: 102: 25:infinite descent 4603: 4602: 4598: 4597: 4596: 4594: 4593: 4592: 4568: 4567: 4566: 4561: 4550: 4543: 4488:Category theory 4478:Algebraic logic 4461: 4432:Lambda calculus 4370:Church encoding 4356: 4332:Truth predicate 4188: 4154:Complete theory 4077: 3946: 3942: 3938: 3933: 3925: 3645: and  3641: 3636: 3622: 3598:New Foundations 3566:axiom of choice 3549: 3511:Gödel numbering 3451: and  3443: 3347: 3232: 3182: 3163: 3112:Boolean algebra 3098: 3062:Equiconsistency 3027:Classical logic 3004: 2985:Halting problem 2973: and  2949: and  2937: and  2936: 2931:Theorems ( 2926: 2843: 2838: 2786: 2784:Further reading 2781: 2780: 2767: 2763: 2754: 2750: 2735: 2731: 2717:10.2307/2323064 2700: 2699: 2695: 2686: 2684: 2677: 2672: 2671: 2667: 2658: 2656: 2648: 2647: 2643: 2632:Guy, Richard K. 2628:Conway, John H. 2626: 2625: 2621: 2612: 2608: 2599: 2595: 2582: 2578: 2572: 2552: 2551: 2547: 2538: 2536: 2529: 2524: 2523: 2516: 2507: 2505: 2497: 2496: 2489: 2480: 2478: 2470: 2469: 2462: 2452: 2437: 2436: 2432: 2427: 2415: 2379: 2366: 2353: 2348: 2347: 2321: 2308: 2295: 2290: 2289: 2264: 2251: 2238: 2233: 2232: 2200: 2187: 2176: 2175: 2156: 2155: 2128: 2127: 2126:and hypotenuse 2104: 2103: 2084: 2083: 2046: 2045: 2044: 2021: 2020: 2001: 2000: 1981: 1980: 1957: 1956: 1955:and hypotenuse 1937: 1936: 1917: 1916: 1879: 1866: 1855: 1854: 1833: 1828: 1827: 1806: 1801: 1800: 1779: 1774: 1773: 1752: 1747: 1746: 1745:and hypotenuse 1725: 1720: 1719: 1693: 1692: 1683:: In this case 1599: 1586: 1575: 1574: 1551: 1538: 1527: 1526: 1493: 1492: 1459: 1446: 1433: 1428: 1427: 1406: 1393: 1380: 1375: 1374: 1371: 1365: 1341: 1339: 1316: 1314: 1279: 1277: 1260: 1259: 1243: 1226: 1215: 1214: 1184: 1180: 1147: 1143: 1142: 1131: 1130: 1107: 1086: 1075: 1074: 1052: 1048: 1044: 1024: 1020: 1016: 1005: 1004: 987: 971: 970: 960: 958: 943: 941: 920: 917: 912: 911: 909: 902: 900: 899:, suppose that 893: 885: 883: 866: 864: 856: 854: 845: 843: 828: 826: 788: 780: 760: 759: 710: 694: 689: 688: 663: 647: 625: 617: 616: 555: 542: 534: 533: 506: 496: 483: 482: 473: 467: 428: 427: 415: 413: 399:geometric proof 397:, worked out a 357: 355: 348: 343: 341: 337: 289:height function 278:abelian variety 239: 215:rational points 154: 153: 120: 107: 94: 89: 88: 45:natural numbers 17: 12: 11: 5: 4601: 4599: 4591: 4590: 4585: 4580: 4570: 4569: 4563: 4562: 4548: 4545: 4544: 4542: 4541: 4536: 4531: 4526: 4521: 4520: 4519: 4509: 4504: 4499: 4490: 4485: 4480: 4475: 4473:Abstract logic 4469: 4467: 4463: 4462: 4460: 4459: 4454: 4452:Turing machine 4449: 4444: 4439: 4434: 4429: 4424: 4423: 4422: 4417: 4412: 4407: 4402: 4392: 4390:Computable set 4387: 4382: 4377: 4372: 4366: 4364: 4358: 4357: 4355: 4354: 4349: 4344: 4339: 4334: 4329: 4324: 4319: 4318: 4317: 4312: 4307: 4297: 4292: 4287: 4285:Satisfiability 4282: 4277: 4272: 4271: 4270: 4260: 4259: 4258: 4248: 4247: 4246: 4241: 4236: 4231: 4226: 4216: 4215: 4214: 4209: 4202:Interpretation 4198: 4196: 4190: 4189: 4187: 4186: 4181: 4176: 4171: 4166: 4156: 4151: 4150: 4149: 4148: 4147: 4137: 4132: 4122: 4117: 4112: 4107: 4102: 4097: 4091: 4089: 4083: 4082: 4079: 4078: 4076: 4075: 4067: 4066: 4065: 4064: 4059: 4058: 4057: 4052: 4047: 4027: 4026: 4025: 4023:minimal axioms 4020: 4009: 4008: 4007: 3996: 3995: 3994: 3989: 3984: 3979: 3974: 3969: 3956: 3954: 3935: 3934: 3932: 3931: 3930: 3929: 3917: 3912: 3911: 3910: 3905: 3900: 3895: 3885: 3880: 3875: 3870: 3869: 3868: 3863: 3853: 3852: 3851: 3846: 3841: 3836: 3826: 3821: 3820: 3819: 3814: 3809: 3799: 3798: 3797: 3792: 3787: 3782: 3777: 3772: 3762: 3757: 3752: 3747: 3746: 3745: 3740: 3735: 3730: 3720: 3715: 3713:Formation rule 3710: 3705: 3704: 3703: 3698: 3688: 3687: 3686: 3676: 3671: 3666: 3661: 3655: 3649: 3632:Formal systems 3628: 3627: 3624: 3623: 3621: 3620: 3615: 3610: 3605: 3600: 3595: 3590: 3585: 3580: 3575: 3574: 3573: 3568: 3557: 3555: 3551: 3550: 3548: 3547: 3546: 3545: 3535: 3530: 3529: 3528: 3521:Large cardinal 3518: 3513: 3508: 3503: 3498: 3484: 3483: 3482: 3477: 3472: 3457: 3455: 3445: 3444: 3442: 3441: 3440: 3439: 3434: 3429: 3419: 3414: 3409: 3404: 3399: 3394: 3389: 3384: 3379: 3374: 3369: 3364: 3358: 3356: 3349: 3348: 3346: 3345: 3344: 3343: 3338: 3333: 3328: 3323: 3318: 3310: 3309: 3308: 3303: 3293: 3288: 3286:Extensionality 3283: 3281:Ordinal number 3278: 3268: 3263: 3262: 3261: 3250: 3244: 3238: 3237: 3234: 3233: 3231: 3230: 3225: 3220: 3215: 3210: 3205: 3200: 3199: 3198: 3188: 3187: 3186: 3173: 3171: 3165: 3164: 3162: 3161: 3160: 3159: 3154: 3149: 3139: 3134: 3129: 3124: 3119: 3114: 3108: 3106: 3100: 3099: 3097: 3096: 3091: 3086: 3081: 3076: 3071: 3066: 3065: 3064: 3054: 3049: 3044: 3039: 3034: 3029: 3023: 3021: 3012: 3006: 3005: 3003: 3002: 2997: 2992: 2987: 2982: 2977: 2965:Cantor's  2963: 2958: 2953: 2943: 2941: 2928: 2927: 2925: 2924: 2919: 2914: 2909: 2904: 2899: 2894: 2889: 2884: 2879: 2874: 2869: 2864: 2863: 2862: 2851: 2849: 2845: 2844: 2839: 2837: 2836: 2829: 2822: 2814: 2808: 2807: 2797: 2785: 2782: 2779: 2778: 2761: 2748: 2729: 2693: 2665: 2641: 2619: 2606: 2593: 2576: 2570: 2545: 2514: 2487: 2460: 2450: 2429: 2428: 2426: 2423: 2422: 2421: 2414: 2411: 2400: 2399: 2386: 2382: 2378: 2373: 2369: 2365: 2360: 2356: 2345: 2333: 2328: 2324: 2320: 2315: 2311: 2307: 2302: 2298: 2287: 2276: 2271: 2267: 2263: 2258: 2254: 2250: 2245: 2241: 2222: 2221: 2207: 2203: 2199: 2194: 2190: 2186: 2183: 2163: 2135: 2113: 2091: 2067: 2053: 2030: 2008: 1988: 1966: 1944: 1924: 1900: 1886: 1882: 1878: 1873: 1869: 1865: 1862: 1840: 1836: 1813: 1809: 1786: 1782: 1759: 1755: 1732: 1728: 1705: 1702: 1634:odd and hence 1606: 1602: 1598: 1593: 1589: 1585: 1582: 1563: 1558: 1554: 1550: 1545: 1541: 1537: 1534: 1515: 1512: 1509: 1506: 1503: 1500: 1466: 1462: 1458: 1453: 1449: 1445: 1440: 1436: 1413: 1409: 1405: 1400: 1396: 1392: 1387: 1383: 1364: 1349: 1274: 1273: 1255: 1252: 1249: 1246: 1241: 1238: 1235: 1232: 1229: 1223: 1220: 1218: 1216: 1210: 1207: 1204: 1200: 1195: 1192: 1187: 1183: 1178: 1175: 1172: 1167: 1161: 1155: 1150: 1146: 1139: 1136: 1134: 1132: 1126: 1123: 1120: 1115: 1110: 1105: 1102: 1099: 1094: 1089: 1083: 1080: 1078: 1076: 1069: 1065: 1062: 1057: 1051: 1047: 1041: 1037: 1034: 1029: 1023: 1019: 1013: 1010: 1008: 1006: 1001: 998: 993: 990: 988: 984: 979: 978: 892: 880: 825:Therefore, if 823: 822: 808: 805: 800: 794: 791: 786: 783: 777: 772: 769: 734: 733: 722: 717: 713: 709: 706: 701: 697: 686: 675: 670: 666: 662: 659: 654: 650: 646: 643: 640: 637: 632: 628: 624: 595:Euclid's lemma 579: 578: 567: 562: 558: 554: 549: 545: 541: 531: 520: 513: 509: 503: 499: 493: 490: 464: 463: 450: 447: 442: 437: 391:ancient Greeks 367:ancient Greeks 347: 338: 336: 333: 238: 235: 219:elliptic curve 182: 179: 175: 172: 167: 164: 161: 127: 123: 119: 114: 110: 106: 101: 97: 15: 13: 10: 9: 6: 4: 3: 2: 4600: 4589: 4586: 4584: 4581: 4579: 4576: 4575: 4573: 4560: 4559: 4554: 4546: 4540: 4537: 4535: 4532: 4530: 4527: 4525: 4522: 4518: 4515: 4514: 4513: 4510: 4508: 4505: 4503: 4500: 4498: 4494: 4491: 4489: 4486: 4484: 4481: 4479: 4476: 4474: 4471: 4470: 4468: 4464: 4458: 4455: 4453: 4450: 4448: 4447:Recursive set 4445: 4443: 4440: 4438: 4435: 4433: 4430: 4428: 4425: 4421: 4418: 4416: 4413: 4411: 4408: 4406: 4403: 4401: 4398: 4397: 4396: 4393: 4391: 4388: 4386: 4383: 4381: 4378: 4376: 4373: 4371: 4368: 4367: 4365: 4363: 4359: 4353: 4350: 4348: 4345: 4343: 4340: 4338: 4335: 4333: 4330: 4328: 4325: 4323: 4320: 4316: 4313: 4311: 4308: 4306: 4303: 4302: 4301: 4298: 4296: 4293: 4291: 4288: 4286: 4283: 4281: 4278: 4276: 4273: 4269: 4266: 4265: 4264: 4261: 4257: 4256:of arithmetic 4254: 4253: 4252: 4249: 4245: 4242: 4240: 4237: 4235: 4232: 4230: 4227: 4225: 4222: 4221: 4220: 4217: 4213: 4210: 4208: 4205: 4204: 4203: 4200: 4199: 4197: 4195: 4191: 4185: 4182: 4180: 4177: 4175: 4172: 4170: 4167: 4164: 4163:from ZFC 4160: 4157: 4155: 4152: 4146: 4143: 4142: 4141: 4138: 4136: 4133: 4131: 4128: 4127: 4126: 4123: 4121: 4118: 4116: 4113: 4111: 4108: 4106: 4103: 4101: 4098: 4096: 4093: 4092: 4090: 4088: 4084: 4074: 4073: 4069: 4068: 4063: 4062:non-Euclidean 4060: 4056: 4053: 4051: 4048: 4046: 4045: 4041: 4040: 4038: 4035: 4034: 4032: 4028: 4024: 4021: 4019: 4016: 4015: 4014: 4010: 4006: 4003: 4002: 4001: 3997: 3993: 3990: 3988: 3985: 3983: 3980: 3978: 3975: 3973: 3970: 3968: 3965: 3964: 3962: 3958: 3957: 3955: 3950: 3944: 3939:Example  3936: 3928: 3923: 3922: 3921: 3918: 3916: 3913: 3909: 3906: 3904: 3901: 3899: 3896: 3894: 3891: 3890: 3889: 3886: 3884: 3881: 3879: 3876: 3874: 3871: 3867: 3864: 3862: 3859: 3858: 3857: 3854: 3850: 3847: 3845: 3842: 3840: 3837: 3835: 3832: 3831: 3830: 3827: 3825: 3822: 3818: 3815: 3813: 3810: 3808: 3805: 3804: 3803: 3800: 3796: 3793: 3791: 3788: 3786: 3783: 3781: 3778: 3776: 3773: 3771: 3768: 3767: 3766: 3763: 3761: 3758: 3756: 3753: 3751: 3748: 3744: 3741: 3739: 3736: 3734: 3731: 3729: 3726: 3725: 3724: 3721: 3719: 3716: 3714: 3711: 3709: 3706: 3702: 3699: 3697: 3696:by definition 3694: 3693: 3692: 3689: 3685: 3682: 3681: 3680: 3677: 3675: 3672: 3670: 3667: 3665: 3662: 3660: 3657: 3656: 3653: 3650: 3648: 3644: 3639: 3633: 3629: 3619: 3616: 3614: 3611: 3609: 3606: 3604: 3601: 3599: 3596: 3594: 3591: 3589: 3586: 3584: 3583:Kripke–Platek 3581: 3579: 3576: 3572: 3569: 3567: 3564: 3563: 3562: 3559: 3558: 3556: 3552: 3544: 3541: 3540: 3539: 3536: 3534: 3531: 3527: 3524: 3523: 3522: 3519: 3517: 3514: 3512: 3509: 3507: 3504: 3502: 3499: 3496: 3492: 3488: 3485: 3481: 3478: 3476: 3473: 3471: 3468: 3467: 3466: 3462: 3459: 3458: 3456: 3454: 3450: 3446: 3438: 3435: 3433: 3430: 3428: 3427:constructible 3425: 3424: 3423: 3420: 3418: 3415: 3413: 3410: 3408: 3405: 3403: 3400: 3398: 3395: 3393: 3390: 3388: 3385: 3383: 3380: 3378: 3375: 3373: 3370: 3368: 3365: 3363: 3360: 3359: 3357: 3355: 3350: 3342: 3339: 3337: 3334: 3332: 3329: 3327: 3324: 3322: 3319: 3317: 3314: 3313: 3311: 3307: 3304: 3302: 3299: 3298: 3297: 3294: 3292: 3289: 3287: 3284: 3282: 3279: 3277: 3273: 3269: 3267: 3264: 3260: 3257: 3256: 3255: 3252: 3251: 3248: 3245: 3243: 3239: 3229: 3226: 3224: 3221: 3219: 3216: 3214: 3211: 3209: 3206: 3204: 3201: 3197: 3194: 3193: 3192: 3189: 3185: 3180: 3179: 3178: 3175: 3174: 3172: 3170: 3166: 3158: 3155: 3153: 3150: 3148: 3145: 3144: 3143: 3140: 3138: 3135: 3133: 3130: 3128: 3125: 3123: 3120: 3118: 3115: 3113: 3110: 3109: 3107: 3105: 3104:Propositional 3101: 3095: 3092: 3090: 3087: 3085: 3082: 3080: 3077: 3075: 3072: 3070: 3067: 3063: 3060: 3059: 3058: 3055: 3053: 3050: 3048: 3045: 3043: 3040: 3038: 3035: 3033: 3032:Logical truth 3030: 3028: 3025: 3024: 3022: 3020: 3016: 3013: 3011: 3007: 3001: 2998: 2996: 2993: 2991: 2988: 2986: 2983: 2981: 2978: 2976: 2972: 2968: 2964: 2962: 2959: 2957: 2954: 2952: 2948: 2945: 2944: 2942: 2940: 2934: 2929: 2923: 2920: 2918: 2915: 2913: 2910: 2908: 2905: 2903: 2900: 2898: 2895: 2893: 2890: 2888: 2885: 2883: 2880: 2878: 2875: 2873: 2870: 2868: 2865: 2861: 2858: 2857: 2856: 2853: 2852: 2850: 2846: 2842: 2835: 2830: 2828: 2823: 2821: 2816: 2815: 2812: 2805: 2801: 2798: 2795: 2791: 2788: 2787: 2783: 2775: 2771: 2765: 2762: 2758: 2752: 2749: 2745: 2744: 2739: 2733: 2730: 2726: 2722: 2718: 2714: 2710: 2706: 2705: 2697: 2694: 2683: 2676: 2669: 2666: 2655: 2651: 2645: 2642: 2637: 2633: 2629: 2623: 2620: 2616: 2610: 2607: 2603: 2600:Brian Clegg, 2597: 2594: 2590: 2586: 2580: 2577: 2573: 2571:0-8176-3141-0 2567: 2563: 2559: 2555: 2549: 2546: 2535: 2528: 2521: 2519: 2515: 2504: 2503:brilliant.org 2500: 2494: 2492: 2488: 2477: 2473: 2467: 2465: 2461: 2457: 2453: 2447: 2443: 2442: 2434: 2431: 2424: 2420: 2419:Vieta jumping 2417: 2416: 2412: 2410: 2408: 2403: 2384: 2380: 2376: 2371: 2367: 2363: 2358: 2354: 2346: 2331: 2326: 2322: 2318: 2313: 2309: 2305: 2300: 2296: 2288: 2274: 2269: 2265: 2261: 2256: 2252: 2248: 2243: 2239: 2231: 2230: 2229: 2226: 2205: 2201: 2197: 2192: 2188: 2184: 2181: 2161: 2153: 2149: 2133: 2111: 2089: 2081: 2077: 2076: 2072: 2068: 2051: 2028: 2006: 1986: 1964: 1942: 1922: 1914: 1910: 1909: 1905: 1901: 1884: 1880: 1876: 1871: 1867: 1863: 1860: 1838: 1834: 1811: 1807: 1784: 1780: 1757: 1753: 1730: 1726: 1703: 1700: 1690: 1686: 1682: 1681: 1677: 1673: 1672: 1671: 1669: 1665: 1661: 1657: 1653: 1649: 1645: 1641: 1637: 1633: 1629: 1626: 1622: 1604: 1600: 1596: 1591: 1587: 1583: 1580: 1561: 1556: 1552: 1548: 1543: 1539: 1535: 1532: 1513: 1510: 1507: 1504: 1501: 1498: 1488: 1486: 1482: 1464: 1460: 1456: 1451: 1447: 1443: 1438: 1434: 1411: 1407: 1403: 1398: 1394: 1390: 1385: 1381: 1370: 1362: 1358: 1354: 1350: 1348: 1344: 1337: 1333: 1329: 1325: 1319: 1312: 1308: 1304: 1300: 1296: 1292: 1288: 1285: âˆ’  1282: 1253: 1250: 1247: 1244: 1239: 1236: 1233: 1230: 1227: 1221: 1219: 1208: 1205: 1202: 1198: 1193: 1190: 1185: 1181: 1176: 1173: 1170: 1165: 1159: 1153: 1148: 1144: 1137: 1135: 1124: 1121: 1118: 1113: 1108: 1103: 1100: 1097: 1092: 1087: 1081: 1079: 1067: 1063: 1060: 1055: 1049: 1045: 1039: 1035: 1032: 1027: 1021: 1017: 1011: 1009: 999: 996: 991: 989: 982: 969: 968: 967: 963: 956: 952: 946: 939: 935: 931: 923: 915: 905: 898: 888: 881: 879: 877: 873: 861: 852: 841: 837: 836: 806: 803: 798: 792: 789: 784: 781: 775: 770: 767: 758: 757: 756: 753: 751: 747: 743: 739: 720: 715: 711: 707: 704: 699: 695: 687: 673: 668: 664: 660: 657: 652: 644: 641: 635: 630: 626: 622: 615: 614: 613: 610: 608: 604: 600: 596: 592: 588: 584: 565: 560: 556: 552: 547: 543: 539: 532: 518: 511: 507: 501: 497: 491: 488: 481: 480: 479: 476: 470: 448: 445: 440: 435: 426: 425: 424: 422: 412:Suppose that 410: 408: 404: 400: 396: 393:, not having 392: 387: 385: 380: 376: 372: 368: 364: 353: 339: 334: 332: 330: 326: 322: 318: 314: 310: 306: 302: 298: 294: 290: 286: 282: 279: 274: 272: 268: 264: 260: 256: 252: 248: 244: 243:number theory 237:Number theory 236: 234: 231: 227: 223: 220: 216: 212: 207: 205: 201: 197: 177: 173: 165: 162: 159: 151: 147: 143: 125: 121: 117: 112: 108: 104: 99: 95: 86: 82: 77: 75: 71: 70: 63: 61: 56: 54: 53:contradiction 50: 46: 41: 39: 35: 30: 26: 23:, a proof by 22: 4549: 4347:Ultraproduct 4194:Model theory 4159:Independence 4095:Formal proof 4087:Proof theory 4070: 4043: 4000:real numbers 3972:second-order 3883:Substitution 3760:Metalanguage 3701:conservative 3674:Axiom schema 3618:Constructive 3588:Morse–Kelley 3554:Set theories 3533:Aleph number 3526:inaccessible 3432:Grothendieck 3316:intersection 3203:Higher-order 3191:Second-order 3137:Truth tables 3094:Venn diagram 2877:Formal proof 2773: 2769: 2764: 2756: 2751: 2741: 2737: 2732: 2708: 2702: 2696: 2685:. Retrieved 2681: 2668: 2657:. Retrieved 2653: 2644: 2635: 2622: 2609: 2596: 2579: 2557: 2548: 2537:. Retrieved 2534:math.uci.edu 2533: 2506:. Retrieved 2502: 2479:. Retrieved 2475: 2455: 2440: 2433: 2406: 2404: 2401: 2227: 2223: 2174:compared to 2151: 2147: 2079: 2074: 2070: 2069: 2043:compared to 1912: 1907: 1903: 1902: 1853:compared to 1688: 1684: 1679: 1675: 1674: 1667: 1663: 1659: 1655: 1651: 1647: 1643: 1639: 1635: 1631: 1624: 1620: 1489: 1372: 1360: 1356: 1352: 1342: 1335: 1331: 1327: 1323: 1317: 1310: 1306: 1302: 1298: 1294: 1290: 1286: 1280: 1275: 961: 950: 944: 937: 933: 929: 921: 913: 903: 896: 894: 886: 875: 871: 862: 835:ad infinitum 833: 824: 754: 749: 745: 741: 740:as well. So 737: 735: 611: 606: 602: 598: 590: 587:prime number 582: 580: 474: 468: 465: 411: 388: 371:Pythagoreans 349: 324: 316: 312: 308: 304: 300: 296: 292: 280: 275: 270: 266: 258: 240: 229: 225: 221: 208: 145: 140:and proving 78: 68: 64: 57: 42: 24: 18: 4457:Type theory 4405:undecidable 4337:Truth value 4224:equivalence 3903:non-logical 3516:Enumeration 3506:Isomorphism 3453:cardinality 3437:Von Neumann 3402:Ultrafilter 3367:Uncountable 3301:equivalence 3218:Quantifiers 3208:Fixed-point 3177:First-order 3057:Consistency 3042:Proposition 3019:Traditional 2990:Lindström's 2980:Compactness 2922:Type theory 2867:Cardinality 2554:Weil, AndrĂ© 851:real number 755:This gives 251:L-functions 21:mathematics 4572:Categories 4268:elementary 3961:arithmetic 3829:Quantifier 3807:functional 3679:Expression 3397:Transitive 3341:identities 3326:complement 3259:hereditary 3242:Set theory 2804:PlanetMath 2794:PlanetMath 2711:(2): 117, 2687:2019-12-10 2659:2019-12-10 2562:BirkhĂ€user 2539:2019-12-10 2508:2019-12-10 2481:2019-12-10 2425:References 1367:See also: 949:(that is, 936:, and let 612:But then, 375:irrational 363:irrational 285:AndrĂ© Weil 4539:Supertask 4442:Recursion 4400:decidable 4234:saturated 4212:of models 4135:deductive 4130:axiomatic 4050:Hilbert's 4037:Euclidean 4018:canonical 3941:axiomatic 3873:Signature 3802:Predicate 3691:Extension 3613:Ackermann 3538:Operation 3417:Universal 3407:Recursive 3382:Singleton 3377:Inhabited 3362:Countable 3352:Types of 3336:power set 3306:partition 3223:Predicate 3169:Predicate 3084:Syllogism 3074:Soundness 3047:Inference 3037:Tautology 2939:paradoxes 1630:and with 1549:− 1248:− 1234:− 1203:− 1171:− 1119:− 1098:− 1061:− 1033:− 966:). Then 407:algebraic 211:inversion 163:≡ 67:Euclid's 4524:Logicism 4517:timeline 4493:Concrete 4352:Validity 4322:T-schema 4315:Kripke's 4310:Tarski's 4305:semantic 4295:Strength 4244:submodel 4239:spectrum 4207:function 4055:Tarski's 4044:Elements 4031:geometry 3987:Robinson 3908:variable 3893:function 3866:spectrum 3856:Sentence 3812:variable 3755:Language 3708:Relation 3669:Automata 3659:Alphabet 3643:language 3497:-jection 3475:codomain 3461:Function 3422:Universe 3392:Infinite 3296:Relation 3079:Validity 3069:Argument 2967:theorem, 2634:(1996), 2556:(1984), 2413:See also 842:. Since 421:rational 379:Hippasus 325:descents 69:Elements 4466:Related 4263:Diagram 4161: ( 4140:Hilbert 4125:Systems 4120:Theorem 3998:of the 3943:systems 3723:Formula 3718:Grammar 3634: ( 3578:General 3291:Forcing 3276:Element 3196:Monadic 2971:paradox 2912:Theorem 2848:General 2725:2323064 1619:, with 1340:√ 1315:√ 1278:√ 959:√ 953:is the 942:√ 926:⁠ 910:⁠ 901:√ 884:√ 865:√ 855:√ 844:√ 827:√ 414:√ 395:algebra 356:√ 342:√ 261:form a 255:Mordell 241:In the 150:squares 4229:finite 3992:Skolem 3945:  3920:Theory 3888:Symbol 3878:String 3861:atomic 3738:ground 3733:closed 3728:atomic 3684:ground 3647:syntax 3543:binary 3470:domain 3387:Finite 3152:finite 3010:Logics 2969:  2917:Theory 2723:  2568:  2448:  838:. But 217:on an 81:Fermat 74:Euclid 4219:Model 3967:Peano 3824:Proof 3664:Arity 3593:Naive 3480:image 3412:Fuzzy 3372:Empty 3321:union 3266:Class 2907:Model 2897:Lemma 2855:Axiom 2721:JSTOR 2678:(PDF) 2530:(PDF) 955:floor 849:is a 597:. So 593:, by 419:were 361:) is 194:(see 152:when 4342:Type 4145:list 3949:list 3926:list 3915:Term 3849:rank 3743:open 3637:list 3449:Maps 3354:sets 3213:Free 3183:list 2933:list 2860:list 2566:ISBN 2446:ISBN 2150:and 2102:and 2073:and 1999:and 1935:and 1906:and 1718:and 1687:and 1678:and 1666:and 1654:nor 1646:and 1638:and 1623:and 1330:and 1309:and 1301:and 1293:and 932:and 472:and 389:The 198:and 4029:of 4011:of 3959:of 3491:Sur 3465:Map 3272:Ur- 3254:Set 2802:at 2792:at 2740:", 2713:doi 2344:and 1632:a+b 957:of 744:= 2 601:= 2 299:)/2 206:). 174:mod 19:In 4574:: 4415:NP 4039:: 4033:: 3963:: 3640:), 3495:Bi 3487:In 2719:, 2709:95 2707:, 2680:. 2652:. 2630:; 2560:, 2532:. 2517:^ 2501:. 2490:^ 2474:. 2463:^ 2454:. 2220:). 2078:: 1911:: 1899:). 1359:= 1355:+ 1332:nâ€Č 1324:mâ€Č 1295:nâ€Č 1291:mâ€Č 752:. 609:. 386:. 283:, 269:/2 55:. 4495:/ 4410:P 4165:) 3951:) 3947:( 3844:∀ 3839:! 3834:∃ 3795:= 3790:↔ 3785:→ 3780:∧ 3775:√ 3770:ÂŹ 3493:/ 3489:/ 3463:/ 3274:) 3270:( 3157:∞ 3147:3 2935:) 2833:e 2826:t 2819:v 2806:. 2796:. 2770:n 2715:: 2690:. 2662:. 2591:. 2542:. 2511:. 2484:. 2407:n 2385:2 2381:t 2377:= 2372:4 2368:s 2364:+ 2359:4 2355:r 2332:, 2327:4 2323:t 2319:= 2314:2 2310:s 2306:+ 2301:4 2297:r 2275:, 2270:4 2266:t 2262:= 2257:4 2253:s 2249:+ 2244:2 2240:r 2206:2 2202:b 2198:+ 2193:2 2189:a 2185:= 2182:z 2162:a 2152:a 2148:b 2134:a 2112:y 2090:b 2080:y 2075:x 2071:y 2066:. 2064:) 2052:z 2029:z 2007:b 1987:a 1965:z 1943:b 1923:a 1913:z 1908:x 1904:z 1885:2 1881:b 1877:+ 1872:2 1868:a 1864:= 1861:z 1839:2 1835:a 1812:2 1808:a 1785:2 1781:b 1758:2 1754:a 1731:2 1727:b 1704:z 1701:y 1689:z 1685:y 1680:z 1676:y 1668:b 1664:a 1660:x 1656:z 1652:y 1648:z 1644:y 1640:z 1636:y 1625:b 1621:a 1605:2 1601:b 1597:+ 1592:2 1588:a 1584:= 1581:z 1562:, 1557:2 1553:b 1544:2 1540:a 1536:= 1533:y 1514:, 1511:b 1508:a 1505:2 1502:= 1499:x 1465:4 1461:t 1457:= 1452:4 1448:s 1444:+ 1439:4 1435:q 1412:4 1408:t 1404:= 1399:4 1395:s 1391:+ 1386:2 1382:r 1361:t 1357:s 1353:r 1343:k 1336:n 1328:m 1318:k 1311:n 1307:m 1303:n 1299:m 1287:q 1281:k 1254:q 1251:n 1245:m 1240:q 1237:m 1231:k 1228:n 1222:= 1209:q 1206:n 1199:) 1194:n 1191:m 1186:( 1182:n 1177:q 1174:m 1166:k 1160:) 1154:k 1149:n 1145:( 1138:= 1125:q 1122:n 1114:k 1109:n 1104:q 1101:m 1093:k 1088:m 1082:= 1068:) 1064:q 1056:k 1050:( 1046:n 1040:) 1036:q 1028:k 1022:( 1018:m 1012:= 1000:n 997:m 992:= 983:k 962:k 951:q 945:k 938:q 934:n 930:m 922:n 918:/ 914:m 904:k 897:k 887:k 876:q 874:/ 872:p 867:2 857:2 846:2 829:2 821:. 807:s 804:r 799:= 793:s 790:2 785:r 782:2 776:= 771:q 768:p 750:s 746:s 742:q 738:q 721:, 716:2 712:r 708:2 705:= 700:2 696:q 674:, 669:2 665:r 661:4 658:= 653:2 649:) 645:r 642:2 639:( 636:= 631:2 627:q 623:2 607:r 603:r 599:p 591:p 583:p 566:, 561:2 557:p 553:= 548:2 544:q 540:2 519:, 512:2 508:q 502:2 498:p 492:= 489:2 475:q 469:p 449:q 446:p 441:= 436:2 416:2 358:2 354:( 344:2 317:A 313:Q 311:( 309:A 305:Q 303:( 301:A 297:Q 295:( 293:A 281:A 271:E 267:E 259:E 230:E 226:E 222:E 181:) 178:4 171:( 166:1 160:p 146:p 126:4 122:t 118:= 113:4 109:s 105:+ 100:2 96:r

Index

mathematics
proof by contradiction
well-ordering principle
Diophantine equation
natural numbers
mathematical induction
contradiction
minimal counterexample
Euclid's Elements
Euclid
Fermat
Diophantine equations
Fermat's theorem on sums of two squares
squares
Modular arithmetic
proof by infinite descent
arithmetic progression
inversion
rational points
elliptic curve
number theory
algebraic number theory
L-functions
Mordell
finitely-generated abelian group
abelian variety
André Weil
height function
Galois cohomology
Mordell–Weil theorem

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