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Proof by infinite descent

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4564: 1282: 983: 58:, 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 1277:{\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}}} 392:
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'
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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
73:—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. 1501:
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
1494:, 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 988: 243:
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.
830: 472: 540: 213:). 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 695: 203: 2353: 2296: 2408: 1488: 1435: 210: 149: 2943: 1583: 2229: 1908: 1628: 742: 587: 1727: 2135: 2052: 1988: 3618: 843:
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
4563: 2360: 1440: 1387: 1300:)—which is positive but less than 1—and then simplified independently. So, the resulting products, say 101: 4410: 4372: 4249: 4053: 3893: 3817: 3795: 3623: 3581: 3480: 3447: 3311: 3099: 3010: 2753: 2572: 2165:) each of which is a square or twice a square, with a smaller hypotenuse than the original triangle ( 1495: 95: 77: 62:, the original premise—that any solution exists—is incorrect: its correctness produces a 48: 1539: 388:. Little is known with certainty about the time or circumstances of this discovery, but the name of 4539: 4430: 4415: 4395: 4352: 4239: 4189: 4115: 4060: 3997: 3790: 3785: 3733: 3501: 3490: 3162: 3062: 2990: 2981: 2977: 2912: 2907: 2188: 1867: 1587: 701: 546: 2482: 1705: 4568: 4337: 4300: 4285: 4278: 4261: 4047: 3913: 3839: 3822: 3775: 3588: 3497: 3331: 3316: 3276: 3228: 3213: 3201: 3157: 3132: 2902: 2851: 2731: 2116: 2033: 1969: 413: 221: 206: 4065: 3521: 4503: 4310: 4120: 4110: 4002: 3883: 3718: 3694: 3475: 3459: 3364: 3341: 3218: 3187: 3152: 3047: 2882: 2576: 2456: 605: 385: 373: 331: 318:) is finite, which is certainly a necessary condition for the finite generation of the group 220:
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
229: 225: 55: 4582: 4457: 4135: 3642: 3427: 3417: 3387: 3372: 3042: 2810: 2564: 2429: 401: 377: 295: 253: 160: 63: 376:(i.e. cannot be expressed as a fraction of two whole numbers) was discovered by the 4357: 4204: 4105: 4097: 3977: 3925: 3834: 3770: 3753: 3684: 3543: 3402: 3104: 2887: 2660: 845: 597: 98:. Two typical examples are showing the non-solvability of the Diophantine equation 2450: 2420:= 4 case of Fermat's Theorem, see the articles by Grant and Perella and Barbara. 4467: 4347: 3526: 3516: 3463: 3147: 3067: 3052: 2932: 2877: 861: 31: 17: 3397: 3252: 3223: 3029: 2814: 2804: 2467:
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.)
864:, which can be either rational or irrational, the only option left is for 4534: 4332: 3780: 3485: 3079: 2800: 2510:"Fermat's Method of Infinite Descent | Brilliant Math & Science Wiki" 2030:) each of which is a square or twice a square, and a smaller hypotenuse ( 389: 4130: 2922: 2735: 1638: 417: 405: 265: 1287:
The numerator and denominator were each multiplied by the expression (
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Number Theory: An approach through history from Hammurapi to Legendre
91: 84: 2727: 2625: 38:, also known as Fermat's method of descent, is a particular kind of 2766:
Grant, Mike, and Perella, Malcolm, "Descending to the irrational",
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Sagher, Yoram (February 1988), "What Pythagoras could have done",
235:. The context is of a hypothetical non-trivial rational point on 2824: 2626:"The discovery of incommensurability by Hippasus of Metapontum" 342:
was at the start of what later became a very extensive theory.
2612: 825:{\displaystyle {\frac {p}{q}}={\frac {2r}{2s}}={\frac {r}{s}}} 76:
The earliest uses of the method of infinite descent appear in
47:, and is often used to show that a given equation, such as a 919:
is not an integer, but is rational and can be expressed as
330:, one must do calculations in what later was recognised as 83:. A typical example is Proposition 31 of Book 7, in which 1437:
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 1902: 1856: 1829: 1802: 1775: 1748: 1721: 1622: 1577: 1529: 1482: 1429: 1358:could be expressed as a ratio of natural numbers. 1276: 824: 736: 689: 581: 534: 466: 197: 143: 2779:Barbara, Roy, "Fermat's last theorem in the case 851:this is impossible in the set of natural numbers 268:, that the rational points on an elliptic curve 27:Mathematical proof technique using contradiction 2836: 1308:, are themselves integers, and are less than 276:, used an infinite descent argument based on 8: 2452:The Moment of Proof: Mathematical Epiphanies 1673:is a square or twice a square, then each of 94:, who coined the term and often used it for 3662: 3257: 3025: 2843: 2829: 2821: 2661:"Square root of 2 is irrational (Proof 8)" 467:{\displaystyle {\sqrt {2}}={\frac {p}{q}}} 2394: 2381: 2368: 2362: 2336: 2323: 2310: 2304: 2279: 2266: 2253: 2247: 2215: 2202: 2190: 2170: 2142: 2120: 2118: 2098: 2060: 2037: 2035: 2015: 1995: 1973: 1971: 1951: 1931: 1894: 1881: 1869: 1848: 1842: 1821: 1815: 1794: 1788: 1767: 1761: 1740: 1734: 1709: 1707: 1614: 1601: 1589: 1566: 1553: 1541: 1507: 1474: 1461: 1448: 1442: 1421: 1408: 1395: 1389: 1235: 1199: 1174: 1162: 1151: 1122: 1101: 1095: 1064: 1036: 1025: 1005: 991: 987: 985: 812: 789: 776: 774: 725: 709: 703: 678: 662: 640: 631: 570: 557: 548: 535:{\displaystyle 2={\frac {p^{2}}{q^{2}}},} 521: 511: 505: 497: 454: 444: 442: 394: 179: 168: 135: 122: 109: 103: 1837:), and would have a smaller hypotenuse ( 1490:in integers, which is a special case of 2455:. Oxford University Press. p. 43. 2441: 1669:can be twice a square. Furthermore, if 690:{\displaystyle 2q^{2}=(2r)^{2}=4r^{2},} 153:Fermat's theorem on sums of two squares 90:The method was much later developed by 1333:, there exist smaller natural numbers 7: 2531: 2529: 2504: 2502: 2477: 2475: 874:(Alternatively, this proves that if 198:{\displaystyle p\equiv 1{\pmod {4}}} 187: 2348:{\displaystyle r^{4}+s^{2}=t^{4},} 2291:{\displaystyle r^{2}+s^{4}=t^{4},} 25: 2747:Dolan, Stan, "Fermat's method of 2403:{\displaystyle r^{4}+s^{4}=t^{2}} 1661:are each odd means that neither 1483:{\displaystyle q^{4}+s^{4}=t^{4}} 1430:{\displaystyle r^{2}+s^{4}=t^{4}} 951:be the largest integer less than 287:To extend this to the case of an 159:can be expressed as a sum of two 155:, which states that an odd prime 144:{\displaystyle r^{2}+s^{4}=t^{4}} 4562: 2811:Example of Fermat's last theorem 2684:Conrad, Keith (August 6, 2008). 2239:This implies that the equations 338:in the tradition of Fermat. The 274:finitely-generated abelian group 747:which shows that 2 must divide 180: 2628:, Annals of Mathematics, 1945. 1578:{\displaystyle y=a^{2}-b^{2},} 659: 649: 434:. Then it could be written as 191: 181: 1: 4523:History of mathematical logic 2715:American Mathematical Monthly 2224:{\displaystyle z=a^{2}+b^{2}} 1903:{\displaystyle z=a^{2}+b^{2}} 1623:{\displaystyle z=a^{2}+b^{2}} 737:{\displaystyle q^{2}=2r^{2},} 582:{\displaystyle 2q^{2}=p^{2},} 224:of the doubling function for 4448:Primitive recursive function 2538:"Fermat's Method of Descent" 1722:{\displaystyle {\sqrt {yz}}} 1653:both odd. The property that 2770:83, July 1999, pp. 263–267. 2615:, Nrich.org, November 2004. 2130:{\displaystyle {\sqrt {y}}} 2047:{\displaystyle {\sqrt {z}}} 1990:also would have two sides ( 1983:{\displaystyle {\sqrt {z}}} 1810:) and a square hypotenuse ( 489:. Then squaring would give 420:proof along similar lines: 264:. The structural result of 4615: 3512:Schröder–Bernstein theorem 3239:Monadic predicate calculus 2898:Foundations of mathematics 2483:"What Is Infinite Descent" 2449:Benson, Donald C. (2000). 1377: 4558: 4545:Philosophy of mathematics 4494:Automated theorem proving 3665: 3619:Von Neumann–Bernays–Gödel 3260: 2613:"The Dangerous Ratio ..." 2596:"The Pythagorean Theorem" 477:for two natural numbers, 211:proof by infinite descent 4599:Mathematical terminology 2649:, Copernicus, p. 25 326:) of rational points of 4195:Self-verifying theories 4016:Tarski's axiomatization 2967:Tarski's undefinability 2962:incompleteness theorems 2787:91, July 2007, 260–262. 2757:95, July 2011, 269–271. 1384:The non-solvability of 902:if it is not an integer 395:Conway & Guy (1996) 393:Constant", for example 258:algebraic number theory 45:well-ordering principle 4569:Mathematics portal 4180:Proof of impossibility 3828:propositional variable 3138:Propositional calculus 2693:kconrad.math.uconn.edu 2598:, Dept. of Math. Ed., 2404: 2349: 2292: 2225: 2179: 2157:would have two sides ( 2151: 2131: 2107: 2069: 2048: 2024: 2004: 1984: 1960: 1940: 1904: 1858: 1831: 1804: 1777: 1750: 1723: 1624: 1579: 1531: 1530:{\displaystyle x=2ab,} 1484: 1431: 1278: 826: 738: 691: 600:, it must also divide 583: 536: 468: 239:. Doubling a point on 215:arithmetic progression 199: 145: 71:minimal counterexample 60:mathematical induction 40:proof by contradiction 4589:Diophantine equations 4438:Kolmogorov complexity 4391:Computably enumerable 4291:Model complete theory 4083:Principia Mathematica 3143:Propositional formula 2972:Banach–Tarski paradox 2600:University of Georgia 2594:Stephanie J. Morris, 2405: 2350: 2293: 2226: 2180: 2152: 2132: 2108: 2070: 2049: 2025: 2005: 1985: 1961: 1941: 1905: 1859: 1857:{\displaystyle a^{2}} 1832: 1830:{\displaystyle a^{2}} 1805: 1803:{\displaystyle b^{2}} 1778: 1776:{\displaystyle a^{2}} 1751: 1749:{\displaystyle b^{2}} 1724: 1625: 1580: 1532: 1492:Fermat's Last Theorem 1485: 1432: 1279: 906:For positive integer 827: 739: 692: 584: 537: 469: 412:by infinite descent ( 200: 146: 96:Diophantine equations 4386:Church–Turing thesis 4373:Computability theory 3582:continuum hypothesis 3100:Square of opposition 2958:Gödel's completeness 2785:Mathematical Gazette 2768:Mathematical Gazette 2754:Mathematical Gazette 2665:www.cut-the-knot.org 2487:www.cut-the-knot.org 2361: 2303: 2246: 2189: 2169: 2141: 2117: 2097: 2059: 2034: 2014: 1994: 1970: 1950: 1930: 1868: 1841: 1814: 1787: 1760: 1733: 1706: 1588: 1540: 1506: 1496:Pythagorean triangle 1441: 1388: 1374:and its permutations 1324:are used to express 984: 939:for natural numbers 773: 702: 630: 547: 496: 441: 346:Application examples 340:Mordell–Weil theorem 167: 102: 51:, has no solutions. 49:Diophantine equation 4594:Mathematical proofs 4540:Mathematical object 4431:P versus NP problem 4396:Computable function 4190:Reverse mathematics 4116:Logical consequence 3993:primitive recursive 3988:elementary function 3761:Free/bound variable 3614:Tarski–Grothendieck 3133:Logical connectives 3063:Logical equivalence 2913:Logical consequence 2647:The Book of Numbers 1362:Non-solvability of 616:, for some integer 361:The proof that the 284:in Fermat's style. 4338:Transfer principle 4301:Semantics of logic 4286:Categorical theory 4262:Non-standard model 3776:Logical connective 2903:Information theory 2852:Mathematical logic 2686:"Infinite Descent" 2575:, pp. 75–79, 2400: 2345: 2288: 2221: 2175: 2147: 2127: 2103: 2065: 2044: 2020: 2000: 1980: 1956: 1936: 1900: 1854: 1827: 1800: 1773: 1746: 1719: 1620: 1575: 1527: 1480: 1427: 1274: 1272: 871:to be irrational. 822: 734: 687: 579: 532: 464: 414:John Horton Conway 207:Modular arithmetic 195: 141: 4576: 4575: 4508:Abstract category 4311:Theories of truth 4121:Rule of inference 4111:Natural deduction 4092: 4091: 3637: 3636: 3342:Cartesian product 3247: 3246: 3153:Many-valued logic 3128:Boolean functions 3011:Russell's paradox 2986:diagonal argument 2883:First-order logic 2783: = 4", 2536:Donaldson, Neil. 2462:978-0-19-513919-8 2178:{\displaystyle a} 2150:{\displaystyle a} 2125: 2106:{\displaystyle b} 2068:{\displaystyle z} 2042: 2023:{\displaystyle b} 2003:{\displaystyle a} 1978: 1959:{\displaystyle b} 1939:{\displaystyle a} 1717: 1268: 1223: 1207: 1179: 1167: 1139: 1127: 1106: 1083: 1069: 1041: 1013: 996: 893:Irrationality of 820: 807: 784: 759:for some integer 596:. Because 2 is a 592:so 2 must divide 527: 462: 449: 351:Irrationality of 332:Galois cohomology 260:and the study of 16:(Redirected from 4606: 4567: 4566: 4518:History of logic 4513:Category of sets 4406:Decision problem 4185:Ordinal analysis 4126:Sequent calculus 4024:Boolean algebras 3964: 3963: 3938: 3909:logical/constant 3663: 3649: 3572:Zermelo–Fraenkel 3323:Set operations: 3258: 3195: 3026: 3006:Löwenheim–Skolem 2893:Formal semantics 2845: 2838: 2831: 2822: 2801:Infinite descent 2788: 2777: 2771: 2764: 2758: 2749:descente infinie 2745: 2739: 2738: 2709: 2703: 2702: 2700: 2699: 2690: 2681: 2675: 2674: 2672: 2671: 2657: 2651: 2650: 2635: 2629: 2624:Kurt von Fritz, 2622: 2616: 2609: 2603: 2592: 2586: 2585: 2561: 2555: 2554: 2552: 2551: 2542: 2533: 2524: 2523: 2521: 2520: 2506: 2497: 2496: 2494: 2493: 2479: 2470: 2469: 2446: 2409: 2407: 2406: 2401: 2399: 2398: 2386: 2385: 2373: 2372: 2354: 2352: 2351: 2346: 2341: 2340: 2328: 2327: 2315: 2314: 2297: 2295: 2294: 2289: 2284: 2283: 2271: 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1236: 1228: 1224: 1222: 1212: 1208: 1200: 1190: 1180: 1175: 1173: 1169: 1168: 1163: 1152: 1144: 1140: 1138: 1128: 1123: 1117: 1107: 1102: 1096: 1088: 1084: 1082: 1081: 1077: 1070: 1065: 1054: 1053: 1049: 1042: 1037: 1026: 1018: 1014: 1006: 997: 992: 976: 975: 959: 958: 938: 936: 935: 930: 927: 918: 917: 901: 900: 880: 879: 870: 869: 859: 858: 842: 841: 831: 829: 828: 823: 821: 813: 808: 806: 798: 790: 785: 777: 743: 741: 740: 735: 730: 729: 714: 713: 696: 694: 693: 688: 683: 682: 667: 666: 645: 644: 588: 586: 585: 580: 575: 574: 562: 561: 541: 539: 538: 533: 528: 526: 525: 516: 515: 506: 488: 482: 473: 471: 470: 465: 463: 455: 450: 445: 429: 428: 371: 370: 363:square root of 2 357: 356: 204: 202: 201: 196: 194: 150: 148: 147: 142: 140: 139: 127: 126: 114: 113: 36:infinite descent 21: 18:Infinite descent 4614: 4613: 4609: 4608: 4607: 4605: 4604: 4603: 4579: 4578: 4577: 4572: 4561: 4554: 4499:Category theory 4489:Algebraic logic 4472: 4443:Lambda calculus 4381:Church encoding 4367: 4343:Truth predicate 4199: 4165:Complete theory 4088: 3957: 3953: 3949: 3944: 3936: 3656: and  3652: 3647: 3633: 3609:New Foundations 3577:axiom of choice 3560: 3522:Gödel numbering 3462: and  3454: 3358: 3243: 3193: 3174: 3123:Boolean algebra 3109: 3073:Equiconsistency 3038:Classical logic 3015: 2996:Halting problem 2984: and  2960: and  2948: and  2947: 2942:Theorems ( 2937: 2854: 2849: 2797: 2795:Further reading 2792: 2791: 2778: 2774: 2765: 2761: 2746: 2742: 2728:10.2307/2323064 2711: 2710: 2706: 2697: 2695: 2688: 2683: 2682: 2678: 2669: 2667: 2659: 2658: 2654: 2643:Guy, Richard K. 2639:Conway, John H. 2637: 2636: 2632: 2623: 2619: 2610: 2606: 2593: 2589: 2583: 2563: 2562: 2558: 2549: 2547: 2540: 2535: 2534: 2527: 2518: 2516: 2508: 2507: 2500: 2491: 2489: 2481: 2480: 2473: 2463: 2448: 2447: 2443: 2438: 2426: 2390: 2377: 2364: 2359: 2358: 2332: 2319: 2306: 2301: 2300: 2275: 2262: 2249: 2244: 2243: 2211: 2198: 2187: 2186: 2167: 2166: 2139: 2138: 2137:and hypotenuse 2115: 2114: 2095: 2094: 2057: 2056: 2055: 2032: 2031: 2012: 2011: 1992: 1991: 1968: 1967: 1966:and hypotenuse 1948: 1947: 1928: 1927: 1890: 1877: 1866: 1865: 1844: 1839: 1838: 1817: 1812: 1811: 1790: 1785: 1784: 1763: 1758: 1757: 1756:and hypotenuse 1736: 1731: 1730: 1704: 1703: 1694:: In this case 1610: 1597: 1586: 1585: 1562: 1549: 1538: 1537: 1504: 1503: 1470: 1457: 1444: 1439: 1438: 1417: 1404: 1391: 1386: 1385: 1382: 1376: 1352: 1350: 1327: 1325: 1290: 1288: 1271: 1270: 1254: 1237: 1226: 1225: 1195: 1191: 1158: 1154: 1153: 1142: 1141: 1118: 1097: 1086: 1085: 1063: 1059: 1055: 1035: 1031: 1027: 1016: 1015: 998: 982: 981: 971: 969: 954: 952: 931: 928: 923: 922: 920: 913: 911: 910:, suppose that 904: 896: 894: 877: 875: 867: 865: 856: 854: 839: 837: 799: 791: 771: 770: 721: 705: 700: 699: 674: 658: 636: 628: 627: 566: 553: 545: 544: 517: 507: 494: 493: 484: 478: 439: 438: 426: 424: 410:geometric proof 408:, worked out a 368: 366: 359: 354: 352: 348: 300:height function 289:abelian variety 250: 226:rational points 165: 164: 131: 118: 105: 100: 99: 56:natural numbers 28: 23: 22: 15: 12: 11: 5: 4612: 4610: 4602: 4601: 4596: 4591: 4581: 4580: 4574: 4573: 4559: 4556: 4555: 4553: 4552: 4547: 4542: 4537: 4532: 4531: 4530: 4520: 4515: 4510: 4501: 4496: 4491: 4486: 4484:Abstract logic 4480: 4478: 4474: 4473: 4471: 4470: 4465: 4463:Turing machine 4460: 4455: 4450: 4445: 4440: 4435: 4434: 4433: 4428: 4423: 4418: 4413: 4403: 4401:Computable set 4398: 4393: 4388: 4383: 4377: 4375: 4369: 4368: 4366: 4365: 4360: 4355: 4350: 4345: 4340: 4335: 4330: 4329: 4328: 4323: 4318: 4308: 4303: 4298: 4296:Satisfiability 4293: 4288: 4283: 4282: 4281: 4271: 4270: 4269: 4259: 4258: 4257: 4252: 4247: 4242: 4237: 4227: 4226: 4225: 4220: 4213:Interpretation 4209: 4207: 4201: 4200: 4198: 4197: 4192: 4187: 4182: 4177: 4167: 4162: 4161: 4160: 4159: 4158: 4148: 4143: 4133: 4128: 4123: 4118: 4113: 4108: 4102: 4100: 4094: 4093: 4090: 4089: 4087: 4086: 4078: 4077: 4076: 4075: 4070: 4069: 4068: 4063: 4058: 4038: 4037: 4036: 4034:minimal axioms 4031: 4020: 4019: 4018: 4007: 4006: 4005: 4000: 3995: 3990: 3985: 3980: 3967: 3965: 3946: 3945: 3943: 3942: 3941: 3940: 3928: 3923: 3922: 3921: 3916: 3911: 3906: 3896: 3891: 3886: 3881: 3880: 3879: 3874: 3864: 3863: 3862: 3857: 3852: 3847: 3837: 3832: 3831: 3830: 3825: 3820: 3810: 3809: 3808: 3803: 3798: 3793: 3788: 3783: 3773: 3768: 3763: 3758: 3757: 3756: 3751: 3746: 3741: 3731: 3726: 3724:Formation rule 3721: 3716: 3715: 3714: 3709: 3699: 3698: 3697: 3687: 3682: 3677: 3672: 3666: 3660: 3643:Formal systems 3639: 3638: 3635: 3634: 3632: 3631: 3626: 3621: 3616: 3611: 3606: 3601: 3596: 3591: 3586: 3585: 3584: 3579: 3568: 3566: 3562: 3561: 3559: 3558: 3557: 3556: 3546: 3541: 3540: 3539: 3532:Large cardinal 3529: 3524: 3519: 3514: 3509: 3495: 3494: 3493: 3488: 3483: 3468: 3466: 3456: 3455: 3453: 3452: 3451: 3450: 3445: 3440: 3430: 3425: 3420: 3415: 3410: 3405: 3400: 3395: 3390: 3385: 3380: 3375: 3369: 3367: 3360: 3359: 3357: 3356: 3355: 3354: 3349: 3344: 3339: 3334: 3329: 3321: 3320: 3319: 3314: 3304: 3299: 3297:Extensionality 3294: 3292:Ordinal number 3289: 3279: 3274: 3273: 3272: 3261: 3255: 3249: 3248: 3245: 3244: 3242: 3241: 3236: 3231: 3226: 3221: 3216: 3211: 3210: 3209: 3199: 3198: 3197: 3184: 3182: 3176: 3175: 3173: 3172: 3171: 3170: 3165: 3160: 3150: 3145: 3140: 3135: 3130: 3125: 3119: 3117: 3111: 3110: 3108: 3107: 3102: 3097: 3092: 3087: 3082: 3077: 3076: 3075: 3065: 3060: 3055: 3050: 3045: 3040: 3034: 3032: 3023: 3017: 3016: 3014: 3013: 3008: 3003: 2998: 2993: 2988: 2976:Cantor's  2974: 2969: 2964: 2954: 2952: 2939: 2938: 2936: 2935: 2930: 2925: 2920: 2915: 2910: 2905: 2900: 2895: 2890: 2885: 2880: 2875: 2874: 2873: 2862: 2860: 2856: 2855: 2850: 2848: 2847: 2840: 2833: 2825: 2819: 2818: 2808: 2796: 2793: 2790: 2789: 2772: 2759: 2740: 2704: 2676: 2652: 2630: 2617: 2604: 2587: 2581: 2556: 2525: 2498: 2471: 2461: 2440: 2439: 2437: 2434: 2433: 2432: 2425: 2422: 2411: 2410: 2397: 2393: 2389: 2384: 2380: 2376: 2371: 2367: 2356: 2344: 2339: 2335: 2331: 2326: 2322: 2318: 2313: 2309: 2298: 2287: 2282: 2278: 2274: 2269: 2265: 2261: 2256: 2252: 2233: 2232: 2218: 2214: 2210: 2205: 2201: 2197: 2194: 2174: 2146: 2124: 2102: 2078: 2064: 2041: 2019: 1999: 1977: 1955: 1935: 1911: 1897: 1893: 1889: 1884: 1880: 1876: 1873: 1851: 1847: 1824: 1820: 1797: 1793: 1770: 1766: 1743: 1739: 1716: 1713: 1645:odd and hence 1617: 1613: 1609: 1604: 1600: 1596: 1593: 1574: 1569: 1565: 1561: 1556: 1552: 1548: 1545: 1526: 1523: 1520: 1517: 1514: 1511: 1477: 1473: 1469: 1464: 1460: 1456: 1451: 1447: 1424: 1420: 1416: 1411: 1407: 1403: 1398: 1394: 1375: 1360: 1285: 1284: 1266: 1263: 1260: 1257: 1252: 1249: 1246: 1243: 1240: 1234: 1231: 1229: 1227: 1221: 1218: 1215: 1211: 1206: 1203: 1198: 1194: 1189: 1186: 1183: 1178: 1172: 1166: 1161: 1157: 1150: 1147: 1145: 1143: 1137: 1134: 1131: 1126: 1121: 1116: 1113: 1110: 1105: 1100: 1094: 1091: 1089: 1087: 1080: 1076: 1073: 1068: 1062: 1058: 1052: 1048: 1045: 1040: 1034: 1030: 1024: 1021: 1019: 1017: 1012: 1009: 1004: 1001: 999: 995: 990: 989: 903: 891: 836:Therefore, if 834: 833: 819: 816: 811: 805: 802: 797: 794: 788: 783: 780: 745: 744: 733: 728: 724: 720: 717: 712: 708: 697: 686: 681: 677: 673: 670: 665: 661: 657: 654: 651: 648: 643: 639: 635: 606:Euclid's lemma 590: 589: 578: 573: 569: 565: 560: 556: 552: 542: 531: 524: 520: 514: 510: 504: 501: 475: 474: 461: 458: 453: 448: 402:ancient Greeks 378:ancient Greeks 358: 349: 347: 344: 249: 246: 230:elliptic curve 193: 190: 186: 183: 178: 175: 172: 138: 134: 130: 125: 121: 117: 112: 108: 26: 24: 14: 13: 10: 9: 6: 4: 3: 2: 4611: 4600: 4597: 4595: 4592: 4590: 4587: 4586: 4584: 4571: 4570: 4565: 4557: 4551: 4548: 4546: 4543: 4541: 4538: 4536: 4533: 4529: 4526: 4525: 4524: 4521: 4519: 4516: 4514: 4511: 4509: 4505: 4502: 4500: 4497: 4495: 4492: 4490: 4487: 4485: 4482: 4481: 4479: 4475: 4469: 4466: 4464: 4461: 4459: 4458:Recursive set 4456: 4454: 4451: 4449: 4446: 4444: 4441: 4439: 4436: 4432: 4429: 4427: 4424: 4422: 4419: 4417: 4414: 4412: 4409: 4408: 4407: 4404: 4402: 4399: 4397: 4394: 4392: 4389: 4387: 4384: 4382: 4379: 4378: 4376: 4374: 4370: 4364: 4361: 4359: 4356: 4354: 4351: 4349: 4346: 4344: 4341: 4339: 4336: 4334: 4331: 4327: 4324: 4322: 4319: 4317: 4314: 4313: 4312: 4309: 4307: 4304: 4302: 4299: 4297: 4294: 4292: 4289: 4287: 4284: 4280: 4277: 4276: 4275: 4272: 4268: 4267:of arithmetic 4265: 4264: 4263: 4260: 4256: 4253: 4251: 4248: 4246: 4243: 4241: 4238: 4236: 4233: 4232: 4231: 4228: 4224: 4221: 4219: 4216: 4215: 4214: 4211: 4210: 4208: 4206: 4202: 4196: 4193: 4191: 4188: 4186: 4183: 4181: 4178: 4175: 4174:from ZFC 4171: 4168: 4166: 4163: 4157: 4154: 4153: 4152: 4149: 4147: 4144: 4142: 4139: 4138: 4137: 4134: 4132: 4129: 4127: 4124: 4122: 4119: 4117: 4114: 4112: 4109: 4107: 4104: 4103: 4101: 4099: 4095: 4085: 4084: 4080: 4079: 4074: 4073:non-Euclidean 4071: 4067: 4064: 4062: 4059: 4057: 4056: 4052: 4051: 4049: 4046: 4045: 4043: 4039: 4035: 4032: 4030: 4027: 4026: 4025: 4021: 4017: 4014: 4013: 4012: 4008: 4004: 4001: 3999: 3996: 3994: 3991: 3989: 3986: 3984: 3981: 3979: 3976: 3975: 3973: 3969: 3968: 3966: 3961: 3955: 3950:Example  3947: 3939: 3934: 3933: 3932: 3929: 3927: 3924: 3920: 3917: 3915: 3912: 3910: 3907: 3905: 3902: 3901: 3900: 3897: 3895: 3892: 3890: 3887: 3885: 3882: 3878: 3875: 3873: 3870: 3869: 3868: 3865: 3861: 3858: 3856: 3853: 3851: 3848: 3846: 3843: 3842: 3841: 3838: 3836: 3833: 3829: 3826: 3824: 3821: 3819: 3816: 3815: 3814: 3811: 3807: 3804: 3802: 3799: 3797: 3794: 3792: 3789: 3787: 3784: 3782: 3779: 3778: 3777: 3774: 3772: 3769: 3767: 3764: 3762: 3759: 3755: 3752: 3750: 3747: 3745: 3742: 3740: 3737: 3736: 3735: 3732: 3730: 3727: 3725: 3722: 3720: 3717: 3713: 3710: 3708: 3707:by definition 3705: 3704: 3703: 3700: 3696: 3693: 3692: 3691: 3688: 3686: 3683: 3681: 3678: 3676: 3673: 3671: 3668: 3667: 3664: 3661: 3659: 3655: 3650: 3644: 3640: 3630: 3627: 3625: 3622: 3620: 3617: 3615: 3612: 3610: 3607: 3605: 3602: 3600: 3597: 3595: 3594:Kripke–Platek 3592: 3590: 3587: 3583: 3580: 3578: 3575: 3574: 3573: 3570: 3569: 3567: 3563: 3555: 3552: 3551: 3550: 3547: 3545: 3542: 3538: 3535: 3534: 3533: 3530: 3528: 3525: 3523: 3520: 3518: 3515: 3513: 3510: 3507: 3503: 3499: 3496: 3492: 3489: 3487: 3484: 3482: 3479: 3478: 3477: 3473: 3470: 3469: 3467: 3465: 3461: 3457: 3449: 3446: 3444: 3441: 3439: 3438:constructible 3436: 3435: 3434: 3431: 3429: 3426: 3424: 3421: 3419: 3416: 3414: 3411: 3409: 3406: 3404: 3401: 3399: 3396: 3394: 3391: 3389: 3386: 3384: 3381: 3379: 3376: 3374: 3371: 3370: 3368: 3366: 3361: 3353: 3350: 3348: 3345: 3343: 3340: 3338: 3335: 3333: 3330: 3328: 3325: 3324: 3322: 3318: 3315: 3313: 3310: 3309: 3308: 3305: 3303: 3300: 3298: 3295: 3293: 3290: 3288: 3284: 3280: 3278: 3275: 3271: 3268: 3267: 3266: 3263: 3262: 3259: 3256: 3254: 3250: 3240: 3237: 3235: 3232: 3230: 3227: 3225: 3222: 3220: 3217: 3215: 3212: 3208: 3205: 3204: 3203: 3200: 3196: 3191: 3190: 3189: 3186: 3185: 3183: 3181: 3177: 3169: 3166: 3164: 3161: 3159: 3156: 3155: 3154: 3151: 3149: 3146: 3144: 3141: 3139: 3136: 3134: 3131: 3129: 3126: 3124: 3121: 3120: 3118: 3116: 3115:Propositional 3112: 3106: 3103: 3101: 3098: 3096: 3093: 3091: 3088: 3086: 3083: 3081: 3078: 3074: 3071: 3070: 3069: 3066: 3064: 3061: 3059: 3056: 3054: 3051: 3049: 3046: 3044: 3043:Logical truth 3041: 3039: 3036: 3035: 3033: 3031: 3027: 3024: 3022: 3018: 3012: 3009: 3007: 3004: 3002: 2999: 2997: 2994: 2992: 2989: 2987: 2983: 2979: 2975: 2973: 2970: 2968: 2965: 2963: 2959: 2956: 2955: 2953: 2951: 2945: 2940: 2934: 2931: 2929: 2926: 2924: 2921: 2919: 2916: 2914: 2911: 2909: 2906: 2904: 2901: 2899: 2896: 2894: 2891: 2889: 2886: 2884: 2881: 2879: 2876: 2872: 2869: 2868: 2867: 2864: 2863: 2861: 2857: 2853: 2846: 2841: 2839: 2834: 2832: 2827: 2826: 2823: 2816: 2812: 2809: 2806: 2802: 2799: 2798: 2794: 2786: 2782: 2776: 2773: 2769: 2763: 2760: 2756: 2755: 2750: 2744: 2741: 2737: 2733: 2729: 2725: 2721: 2717: 2716: 2708: 2705: 2694: 2687: 2680: 2677: 2666: 2662: 2656: 2653: 2648: 2644: 2640: 2634: 2631: 2627: 2621: 2618: 2614: 2611:Brian Clegg, 2608: 2605: 2601: 2597: 2591: 2588: 2584: 2582:0-8176-3141-0 2578: 2574: 2570: 2566: 2560: 2557: 2546: 2539: 2532: 2530: 2526: 2515: 2514:brilliant.org 2511: 2505: 2503: 2499: 2488: 2484: 2478: 2476: 2472: 2468: 2464: 2458: 2454: 2453: 2445: 2442: 2435: 2431: 2430:Vieta jumping 2428: 2427: 2423: 2421: 2419: 2414: 2395: 2391: 2387: 2382: 2378: 2374: 2369: 2365: 2357: 2342: 2337: 2333: 2329: 2324: 2320: 2316: 2311: 2307: 2299: 2285: 2280: 2276: 2272: 2267: 2263: 2259: 2254: 2250: 2242: 2241: 2240: 2237: 2216: 2212: 2208: 2203: 2199: 2195: 2192: 2172: 2164: 2160: 2144: 2122: 2100: 2092: 2088: 2087: 2083: 2079: 2062: 2039: 2017: 1997: 1975: 1953: 1933: 1925: 1921: 1920: 1916: 1912: 1895: 1891: 1887: 1882: 1878: 1874: 1871: 1849: 1845: 1822: 1818: 1795: 1791: 1768: 1764: 1741: 1737: 1714: 1711: 1701: 1697: 1693: 1692: 1688: 1684: 1683: 1682: 1680: 1676: 1672: 1668: 1664: 1660: 1656: 1652: 1648: 1644: 1640: 1637: 1633: 1615: 1611: 1607: 1602: 1598: 1594: 1591: 1572: 1567: 1563: 1559: 1554: 1550: 1546: 1543: 1524: 1521: 1518: 1515: 1512: 1509: 1499: 1497: 1493: 1475: 1471: 1467: 1462: 1458: 1454: 1449: 1445: 1422: 1418: 1414: 1409: 1405: 1401: 1396: 1392: 1381: 1373: 1369: 1365: 1361: 1359: 1355: 1348: 1344: 1340: 1336: 1330: 1323: 1319: 1315: 1311: 1307: 1303: 1299: 1296: âˆ’  1293: 1264: 1261: 1258: 1255: 1250: 1247: 1244: 1241: 1238: 1232: 1230: 1219: 1216: 1213: 1209: 1204: 1201: 1196: 1192: 1187: 1184: 1181: 1176: 1170: 1164: 1159: 1155: 1148: 1146: 1135: 1132: 1129: 1124: 1119: 1114: 1111: 1108: 1103: 1098: 1092: 1090: 1078: 1074: 1071: 1066: 1060: 1056: 1050: 1046: 1043: 1038: 1032: 1028: 1022: 1020: 1010: 1007: 1002: 1000: 993: 980: 979: 978: 974: 967: 963: 957: 950: 946: 942: 934: 926: 916: 909: 899: 892: 890: 888: 884: 872: 863: 852: 848: 847: 817: 814: 809: 803: 800: 795: 792: 786: 781: 778: 769: 768: 767: 764: 762: 758: 754: 750: 731: 726: 722: 718: 715: 710: 706: 698: 684: 679: 675: 671: 668: 663: 655: 652: 646: 641: 637: 633: 626: 625: 624: 621: 619: 615: 611: 607: 603: 599: 595: 576: 571: 567: 563: 558: 554: 550: 543: 529: 522: 518: 512: 508: 502: 499: 492: 491: 490: 487: 481: 459: 456: 451: 446: 437: 436: 435: 433: 423:Suppose that 421: 419: 415: 411: 407: 404:, not having 403: 398: 396: 391: 387: 383: 379: 375: 364: 350: 345: 343: 341: 337: 333: 329: 325: 321: 317: 313: 309: 305: 301: 297: 293: 290: 285: 283: 279: 275: 271: 267: 263: 259: 255: 254:number theory 248:Number theory 247: 245: 242: 238: 234: 231: 227: 223: 218: 216: 212: 208: 188: 184: 176: 173: 170: 162: 158: 154: 136: 132: 128: 123: 119: 115: 110: 106: 97: 93: 88: 86: 82: 81: 74: 72: 67: 65: 64:contradiction 61: 57: 52: 50: 46: 41: 37: 34:, a proof by 33: 19: 4560: 4358:Ultraproduct 4205:Model theory 4170:Independence 4106:Formal proof 4098:Proof theory 4081: 4054: 4011:real numbers 3983:second-order 3894:Substitution 3771:Metalanguage 3712:conservative 3685:Axiom schema 3629:Constructive 3599:Morse–Kelley 3565:Set theories 3544:Aleph number 3537:inaccessible 3443:Grothendieck 3327:intersection 3214:Higher-order 3202:Second-order 3148:Truth tables 3105:Venn diagram 2888:Formal proof 2784: 2780: 2775: 2767: 2762: 2752: 2748: 2743: 2719: 2713: 2707: 2696:. Retrieved 2692: 2679: 2668:. Retrieved 2664: 2655: 2646: 2633: 2620: 2607: 2590: 2568: 2559: 2548:. Retrieved 2545:math.uci.edu 2544: 2517:. Retrieved 2513: 2490:. Retrieved 2486: 2466: 2451: 2444: 2417: 2415: 2412: 2238: 2234: 2185:compared to 2162: 2158: 2090: 2085: 2081: 2080: 2054:compared to 1923: 1918: 1914: 1913: 1864:compared to 1699: 1695: 1690: 1686: 1685: 1678: 1674: 1670: 1666: 1662: 1658: 1654: 1650: 1646: 1642: 1635: 1631: 1500: 1383: 1371: 1367: 1363: 1353: 1346: 1342: 1338: 1334: 1328: 1321: 1317: 1313: 1309: 1305: 1301: 1297: 1291: 1286: 972: 961: 955: 948: 944: 940: 932: 924: 914: 907: 905: 897: 886: 882: 873: 846:ad infinitum 844: 835: 765: 760: 756: 752: 751:as well. So 748: 746: 622: 617: 613: 609: 601: 598:prime number 593: 591: 485: 479: 476: 422: 399: 382:Pythagoreans 360: 335: 327: 323: 319: 315: 311: 307: 303: 291: 286: 281: 277: 269: 251: 240: 236: 232: 219: 156: 151:and proving 89: 79: 75: 68: 53: 35: 29: 4468:Type theory 4416:undecidable 4348:Truth value 4235:equivalence 3914:non-logical 3527:Enumeration 3517:Isomorphism 3464:cardinality 3448:Von Neumann 3413:Ultrafilter 3378:Uncountable 3312:equivalence 3229:Quantifiers 3219:Fixed-point 3188:First-order 3068:Consistency 3053:Proposition 3030:Traditional 3001:Lindström's 2991:Compactness 2933:Type theory 2878:Cardinality 2565:Weil, AndrĂ© 862:real number 766:This gives 262:L-functions 32:mathematics 4583:Categories 4279:elementary 3972:arithmetic 3840:Quantifier 3818:functional 3690:Expression 3408:Transitive 3352:identities 3337:complement 3270:hereditary 3253:Set theory 2815:PlanetMath 2805:PlanetMath 2722:(2): 117, 2698:2019-12-10 2670:2019-12-10 2573:BirkhĂ€user 2550:2019-12-10 2519:2019-12-10 2492:2019-12-10 2436:References 1378:See also: 960:(that is, 947:, and let 623:But then, 386:irrational 374:irrational 296:AndrĂ© Weil 4550:Supertask 4453:Recursion 4411:decidable 4245:saturated 4223:of models 4146:deductive 4141:axiomatic 4061:Hilbert's 4048:Euclidean 4029:canonical 3952:axiomatic 3884:Signature 3813:Predicate 3702:Extension 3624:Ackermann 3549:Operation 3428:Universal 3418:Recursive 3393:Singleton 3388:Inhabited 3373:Countable 3363:Types of 3347:power set 3317:partition 3234:Predicate 3180:Predicate 3095:Syllogism 3085:Soundness 3058:Inference 3048:Tautology 2950:paradoxes 1641:and with 1560:− 1259:− 1245:− 1214:− 1182:− 1130:− 1109:− 1072:− 1044:− 977:). Then 418:algebraic 222:inversion 174:≡ 78:Euclid's 4535:Logicism 4528:timeline 4504:Concrete 4363:Validity 4333:T-schema 4326:Kripke's 4321:Tarski's 4316:semantic 4306:Strength 4255:submodel 4250:spectrum 4218:function 4066:Tarski's 4055:Elements 4042:geometry 3998:Robinson 3919:variable 3904:function 3877:spectrum 3867:Sentence 3823:variable 3766:Language 3719:Relation 3680:Automata 3670:Alphabet 3654:language 3508:-jection 3486:codomain 3472:Function 3433:Universe 3403:Infinite 3307:Relation 3090:Validity 3080:Argument 2978:theorem, 2645:(1996), 2567:(1984), 2424:See also 853:. Since 432:rational 390:Hippasus 336:descents 80:Elements 4477:Related 4274:Diagram 4172: ( 4151:Hilbert 4136:Systems 4131:Theorem 4009:of the 3954:systems 3734:Formula 3729:Grammar 3645: ( 3589:General 3302:Forcing 3287:Element 3207:Monadic 2982:paradox 2923:Theorem 2859:General 2736:2323064 1630:, with 1351:√ 1326:√ 1289:√ 970:√ 964:is the 953:√ 937:⁠ 921:⁠ 912:√ 895:√ 876:√ 866:√ 855:√ 838:√ 425:√ 406:algebra 367:√ 353:√ 272:form a 266:Mordell 252:In the 161:squares 4240:finite 4003:Skolem 3956:  3931:Theory 3899:Symbol 3889:String 3872:atomic 3749:ground 3744:closed 3739:atomic 3695:ground 3658:syntax 3554:binary 3481:domain 3398:Finite 3163:finite 3021:Logics 2980:  2928:Theory 2734:  2579:  2459:  849:. But 228:on an 92:Fermat 85:Euclid 4230:Model 3978:Peano 3835:Proof 3675:Arity 3604:Naive 3491:image 3423:Fuzzy 3383:Empty 3332:union 3277:Class 2918:Model 2908:Lemma 2866:Axiom 2732:JSTOR 2689:(PDF) 2541:(PDF) 966:floor 860:is a 608:. So 604:, by 430:were 372:) is 205:(see 163:when 4353:Type 4156:list 3960:list 3937:list 3926:Term 3860:rank 3754:open 3648:list 3460:Maps 3365:sets 3224:Free 3194:list 2944:list 2871:list 2577:ISBN 2457:ISBN 2161:and 2113:and 2084:and 2010:and 1946:and 1917:and 1729:and 1698:and 1689:and 1677:and 1665:nor 1657:and 1649:and 1634:and 1341:and 1320:and 1312:and 1304:and 943:and 483:and 400:The 209:and 4040:of 4022:of 3970:of 3502:Sur 3476:Map 3283:Ur- 3265:Set 2813:at 2803:at 2751:", 2724:doi 2355:and 1643:a+b 968:of 755:= 2 612:= 2 310:)/2 217:). 185:mod 30:In 4585:: 4426:NP 4050:: 4044:: 3974:: 3651:), 3506:Bi 3498:In 2730:, 2720:95 2718:, 2691:. 2663:. 2641:; 2571:, 2543:. 2528:^ 2512:. 2501:^ 2485:. 2474:^ 2465:. 2231:). 2089:: 1922:: 1910:). 1370:= 1366:+ 1343:nâ€Č 1335:mâ€Č 1306:nâ€Č 1302:mâ€Č 763:. 620:. 397:. 294:, 280:/2 66:. 4506:/ 4421:P 4176:) 3962:) 3958:( 3855:∀ 3850:! 3845:∃ 3806:= 3801:↔ 3796:→ 3791:∧ 3786:√ 3781:ÂŹ 3504:/ 3500:/ 3474:/ 3285:) 3281:( 3168:∞ 3158:3 2946:) 2844:e 2837:t 2830:v 2817:. 2807:. 2781:n 2726:: 2701:. 2673:. 2602:. 2553:. 2522:. 2495:. 2418:n 2396:2 2392:t 2388:= 2383:4 2379:s 2375:+ 2370:4 2366:r 2343:, 2338:4 2334:t 2330:= 2325:2 2321:s 2317:+ 2312:4 2308:r 2286:, 2281:4 2277:t 2273:= 2268:4 2264:s 2260:+ 2255:2 2251:r 2217:2 2213:b 2209:+ 2204:2 2200:a 2196:= 2193:z 2173:a 2163:a 2159:b 2145:a 2123:y 2101:b 2091:y 2086:x 2082:y 2077:. 2075:) 2063:z 2040:z 2018:b 1998:a 1976:z 1954:b 1934:a 1924:z 1919:x 1915:z 1896:2 1892:b 1888:+ 1883:2 1879:a 1875:= 1872:z 1850:2 1846:a 1823:2 1819:a 1796:2 1792:b 1769:2 1765:a 1742:2 1738:b 1715:z 1712:y 1700:z 1696:y 1691:z 1687:y 1679:b 1675:a 1671:x 1667:z 1663:y 1659:z 1655:y 1651:z 1647:y 1636:b 1632:a 1616:2 1612:b 1608:+ 1603:2 1599:a 1595:= 1592:z 1573:, 1568:2 1564:b 1555:2 1551:a 1547:= 1544:y 1525:, 1522:b 1519:a 1516:2 1513:= 1510:x 1476:4 1472:t 1468:= 1463:4 1459:s 1455:+ 1450:4 1446:q 1423:4 1419:t 1415:= 1410:4 1406:s 1402:+ 1397:2 1393:r 1372:t 1368:s 1364:r 1354:k 1347:n 1339:m 1329:k 1322:n 1318:m 1314:n 1310:m 1298:q 1292:k 1265:q 1262:n 1256:m 1251:q 1248:m 1242:k 1239:n 1233:= 1220:q 1217:n 1210:) 1205:n 1202:m 1197:( 1193:n 1188:q 1185:m 1177:k 1171:) 1165:k 1160:n 1156:( 1149:= 1136:q 1133:n 1125:k 1120:n 1115:q 1112:m 1104:k 1099:m 1093:= 1079:) 1075:q 1067:k 1061:( 1057:n 1051:) 1047:q 1039:k 1033:( 1029:m 1023:= 1011:n 1008:m 1003:= 994:k 973:k 962:q 956:k 949:q 945:n 941:m 933:n 929:/ 925:m 915:k 908:k 898:k 887:q 885:/ 883:p 878:2 868:2 857:2 840:2 832:. 818:s 815:r 810:= 804:s 801:2 796:r 793:2 787:= 782:q 779:p 761:s 757:s 753:q 749:q 732:, 727:2 723:r 719:2 716:= 711:2 707:q 685:, 680:2 676:r 672:4 669:= 664:2 660:) 656:r 653:2 650:( 647:= 642:2 638:q 634:2 618:r 614:r 610:p 602:p 594:p 577:, 572:2 568:p 564:= 559:2 555:q 551:2 530:, 523:2 519:q 513:2 509:p 503:= 500:2 486:q 480:p 460:q 457:p 452:= 447:2 427:2 369:2 365:( 355:2 328:A 324:Q 322:( 320:A 316:Q 314:( 312:A 308:Q 306:( 304:A 292:A 282:E 278:E 270:E 241:E 237:E 233:E 192:) 189:4 182:( 177:1 171:p 157:p 137:4 133:t 129:= 124:4 120:s 116:+ 111:2 107:r 20:)

Index

Infinite descent
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

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