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Jordan curve theorem

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Nearly every modern citation that I have found agrees that the first correct proof is due to Veblen... In view of the heavy criticism of Jordan’s proof, I was surprised when I sat down to read his proof to find nothing objectionable about it. Since then, I have contacted a number of the authors who
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It is clear that Jordan curve theorem implies the "strong Hex theorem": "every game of Hex ends with exactly one winner, with no possibility of both sides losing or both sides winning", thus the Jordan curve theorem is equivalent to the strong Hex theorem, which is a purely
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seems intuitively obvious, it takes some ingenuity to prove it by elementary means. "Although the JCT is one of the best known topological theorems, there are many, even among professional mathematicians, who have never read a proof of it."
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His proof, however, is unsatisfactory to many mathematicians. It assumes the theorem without proof in the important special case of a simple polygon, and of the argument from that point on, one must admit at least that all details are not
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In reverse mathematics, and computer-formalized mathematics, the Jordan curve theorem is commonly proved by first converting it to an equivalent discrete version similar to the strong Hex theorem, then proving the discrete version.
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as follows. It is relatively simple to prove that the Jordan curve theorem holds for every Jordan polygon (Lemma 1), and every Jordan curve can be approximated arbitrarily well by a Jordan polygon (Lemma 2). A Jordan polygon is a
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Both graph structures fail to satisfy the strong Hex theorem. The 4-neighbor square grid allows a no-winner situation, and the 8-neighbor square grid allows a two-winner situation. Consequently, connectedness properties in
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bounded by the curve. This is the point of Tverberg's Lemma 3. Roughly, the closed polygons should not thin to zero everywhere. Moreover, they should not thin to zero somewhere, which is the point of Tverberg's Lemma 4.
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The Steinhaus chessboard theorem in some sense shows that the 4-neighbor grid and the 8-neighbor grid "together" implies the Jordan curve theorem, and the 6-neighbor grid is a precise interpolation between them.
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chessboard, so that a king cannot move from the bottom side to the top side without stepping on a bomb, then a rook can move from the left side to the right side stepping only on bombs.
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Brown, R.; Antolino-Camarena, O. (2014). "Corrigendum to "Groupoids, the Phragmen-Brouwer Property, and the Jordan Curve Theorem", J. Homotopy and Related Structures 1 (2006) 175-183".
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Jordan’s proof is essentially correct... Jordan’s proof does not present the details in a satisfactory way. But the idea is right, and with some polishing the proof would be impeccable.
1802:. Both the Mizar and the HOL Light proof rely on libraries of previously proved theorems, so these two sizes are not comparable. Nobuyuki Sakamoto and Keita Yokoyama ( 1850: 1118: 1353: 1321: 1292: 887: 851: 822: 793: 764: 1798:
system, in January 2005, and contained about 60,000 lines. Another rigorous 6,500-line formal proof was produced in 2005 by an international team of mathematicians using the
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Hales also pointed out that the special case of simple polygons is not only an easy exercise, but was not really used by Jordan anyway, and quoted Michael Reeken as saying:
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was the first to formulate a precise conjecture, observing that it was not a self-evident statement, but that it required a proof. It is easy to establish this result for
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Illustration of the Jordan curve theorem. The Jordan curve (drawn in black) divides the plane into an "inside" region (light blue) and an "outside" region (pink).
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has at least one winner", from which we obtain a logical implication: Hex theorem implies Brouwer fixed point theorem, which implies Jordan curve theorem.
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Adler, Aviv; Daskalakis, Constantinos; Demaine, Erik D. (2016). Chatzigiannakis, Ioannis; Mitzenmacher, Michael; Rabani, Yuval; Sangiorgi, Davide (eds.).
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consists of exactly two connected components. One of these components is bounded (the interior) and the other is unbounded (the exterior). The set
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of intersections of the ray with an edge of the polygon. Jordan curve theorem proof implies that the point is inside the polygon if and only if
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Sakamoto, Nobuyuki; Yokoyama, Keita (2007), "The Jordan curve theorem and the Schönflies theorem in weak second-order arithmetic",
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New elementary proofs of the Jordan curve theorem, as well as simplifications of the earlier proofs, continue to be carried out.
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that does not pass through any vertex of the polygon (all rays but a finite number are convenient). Then, compute the number
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have criticized Jordan, and each case the author has admitted to having no direct knowledge of an error in Jordan’s proof.
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The Brouwer fixed point theorem, by being sandwiched between the two equivalent theorems, is also equivalent to both.
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A proof using constructive mathematics by Gordon O. Berg, W. Julian, and R. Mines et al. (
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The statement of the Jordan curve theorem may seem obvious at first, but it is a rather difficult theorem to prove.
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in the plane is the image of an injective continuous map of a closed and bounded interval into the plane. It is a
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of the plane. Unlike Lebesgue's and Brouwer's generalization of the Jordan curve theorem, this statement becomes
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is positive. Using a sequence of Jordan polygons (that converge to the given Jordan curve) we have a sequence
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Johnson, Dale M. (1977). "Prelude to dimension theory: the geometrical investigations of Bernard Bolzano".
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Nguyen, Phuong; Cook, Stephen A. (2007). "The Complexity of Proving the Discrete Jordan Curve Theorem".
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connecting a point of one region to a point of the other intersects with the curve somewhere. While the
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Berg, Gordon O.; Julian, W.; Mines, R.; Richman, Fred (1975), "The constructive Jordan curve theorem",
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Adler, Daskalakis and Demaine prove that a computational version of Jordan's theorem is
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Maehara, Ryuji (1984), "The Jordan Curve Theorem Via the Brouwer Fixed Point Theorem",
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Hales, Thomas C. (December 2007). "The Jordan Curve Theorem, Formally and Informally".
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is not simply connected, and hence not homeomorphic to the exterior of the unit ball.
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Gale, David (December 1979). "The Game of Hex and the Brouwer Fixed-Point Theorem".
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43rd International Colloquium on Automata, Languages, and Programming (ICALP 2016)
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Ross, Fiona; Ross, William T. (2011), "The Jordan curve theorem is non-trivial",
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The Jordan curve theorem was independently generalized to higher dimensions by
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does not converge to zero, using only the given Jordan curve, not the region
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With these definitions, the Jordan curve theorem can be stated as follows:
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had already been critically analyzed and completed by Schoenflies (1924).
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What is mathematics? : an elementary approach to ideas and methods
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The theorem states that: suppose you put bombs on some squares on a
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22nd Annual IEEE Symposium on Logic in Computer Science (LICS 2007)
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There is a strengthening of the Jordan curve theorem, called the
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is a continuous loop, whereas the last condition stipulates that
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of the largest disk contained in the closed polygon. Evidently,
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Alternatively, a Jordan curve is the image of a continuous map
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Osgood, William F. (1903), "A Jordan Curve of Positive Area",
2628:(2007a), "The Jordan curve theorem, formally and informally", 2452:"PNPOLY - Point Inclusion in Polygon Test - WR Franklin (WRF)" 1961:. As a corollary, they show that Jordan's theorem implies the 2483:. Leibniz International Proceedings in Informatics (LIPIcs). 1886:), the number of intersections of the ray and the polygon is 666:
in higher dimensions: while the exterior of the unit ball in
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Courant, Richard (1978). "V. Topology". Written at Oxford.
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The full 6,500 line formal proof of Jordan's curve theorem
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Kline, J. R. (1942). "What is the Jordan curve theorem?".
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on the Jordan curve, there exists a Jordan arc connecting
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to [0,1) is injective. The first two conditions say that
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If the "6-neighbor square grid" structure is imposed on
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Due to the importance of the Jordan curve theorem in
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Definitions and the statement of the Jordan theorem
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If 547:has 2 connected components (which are, moreover, 27:A closed curve divides the plane into two regions 3109: 3081:Collection of proofs of the Jordan curve theorem 2885: 2256:"A digital analogue of the Jordan curve theorem" 1880:(in red) lies outside a simple polygon (region 1803: 1046:the "8-neighbor square grid", where each vertex 901:the "4-neighbor square grid", where each vertex 702:The Jordan curve theorem can be proved from the 1448:, who said the following about Jordan's proof: 1358: 1036:{\displaystyle (x+1,y),(x-1,y),(x,y+1),(x,y-1)} 2395: 1771:{\displaystyle \delta _{1},\delta _{2},\dots } 1704:converging to a positive number, the diameter 1694:{\displaystyle \delta _{1},\delta _{2},\dots } 583:-dimensional compact connected submanifold of 99:. However, this notion has been overturned by 1918:Point in polygon § Ray casting algorithm 1432:The first proof of this theorem was given by 1396: 2679:"Jordan's proof of the Jordan Curve theorem" 2068:"Jordan's proof of the Jordan curve theorem" 1615:, the closed polygon. Consider the diameter 487: 481: 268: 88:The Jordan curve theorem is named after the 2974:Bulletin of the London Mathematical Society 1903:) of a ray lies inside the polygon (region 1790:of the Jordan curve theorem was created by 1598:The root of the difficulty is explained in 2146: 1810:the Jordan curve theorem is equivalent to 860:There are two obvious graph structures on 3098: 3021: 2986: 2929: 2819: 2779: 2607:"An elementary proof of Jordan's theorem" 2548: 2492: 2297:"A discrete form of Jordan curve theorem" 2271: 2156: 1591: 1335: 1303: 1274: 1193:{\displaystyle |x-x'|\leq 1,|y-y'|\leq 1} 869: 833: 804: 775: 746: 436: 2960: 2851: 2601: 1952: 1860: 1599: 1541: 1537: 1442:Cours d'analyse de l'École Polytechnique 891: 626:and, with the exception of the endpoint 555:. A further generalization was found by 261:In contrast, the complement of a Jordan 78: 29: 2713: 2572: 2517: 2418: 2321: 2294: 2091: 1570: 896:8-neighbor and 4-neighbor square grids. 853:does not have an appropriately defined 14: 3110: 3087:A simple proof of Jordan curve theorem 3002: 2803: 2759: 2696: 2686:Studies in Logic, Grammar and Rhetoric 2673: 2624: 2384: 2373: 2361: 2253: 2075:Studies in Logic, Grammar and Rhetoric 2007: 1831: 1828: 1825: 1791: 1607:, the boundary of a bounded connected 1552: 1426: 2966:"A proof of the Jordan curve theorem" 2536:Rocky Mountain Journal of Mathematics 2324:Archive for History of Exact Sciences 2232: 2189: 2062: 2019: 1724:of the largest disk contained in the 2103: 1611:, call it the open polygon, and its 1536:Elementary proofs were presented by 606:to the interior and exterior of the 2855:Journal of Mathematics and the Arts 1845:{\displaystyle {\mathsf {RCA}}_{0}} 697: 614:in the interior region and a point 24: 1909:), the number of intersections is 563:between the reduced homology of a 245:) and the other is unbounded (the 25: 3134: 3046: 2717:The American Mathematical Monthly 2631:The American Mathematical Monthly 2192:The American Mathematical Monthly 2106:The American Mathematical Monthly 1480:Charles Jean de la VallĂ©e Poussin 1253:{\displaystyle (x,y)\neq (x',y')} 539:, the zeroth reduced homology of 283:Jordan–Brouwer separation theorem 200:has no self-intersection points. 2401:Jahresber. Deutsch. Math.-Verein 1440:, and was published in his book 1348:{\displaystyle \mathbb {Z} ^{2}} 1316:{\displaystyle \mathbb {Z} ^{2}} 1287:{\displaystyle \mathbb {R} ^{2}} 882:{\displaystyle \mathbb {Z} ^{2}} 846:{\displaystyle \mathbb {Z} ^{2}} 817:{\displaystyle \mathbb {Z} ^{2}} 788:{\displaystyle \mathbb {R} ^{2}} 759:{\displaystyle \mathbb {Z} ^{2}} 2468: 2444: 2424: 2411: 2389: 2378: 2367: 2351: 2315: 2301:Annales Mathematicae Silesianae 2288: 1423:a Jordan curve of positive area 729:Application to image processing 610:. In particular, for any point 523:This is proved by induction in 217:be a Jordan curve in the plane 2888:Archive for Mathematical Logic 2767:Pacific Journal of Mathematics 2644:10.1080/00029890.2007.11920481 2247: 2226: 2204:10.1080/00029890.2007.11920481 2183: 2140: 2097: 2081:(23). University of BiaĹ‚ystok. 2056: 2013: 1856: 1323:under either graph structure. 1247: 1225: 1219: 1207: 1180: 1161: 1147: 1128: 1107: 1085: 1065: 1053: 1030: 1012: 1006: 988: 982: 964: 958: 940: 920: 908: 421: 415: 403: 13: 1: 3053:M.I. Voitsekhovskii (2001) , 2935:American Mathematical Monthly 2526: 2022:American Mathematical Monthly 543:has rank 1, which means that 237:. One of these components is 3083:at Andrew Ranicki's homepage 2868:10.1080/17513472.2011.634320 2494:10.4230/LIPIcs.ICALP.2016.24 2260:Discrete Applied Mathematics 2233:Nayar, Shree (Mar 1, 2021). 1933:From a given point, trace a 1359:Steinhaus chessboard theorem 766:. Topological invariants on 50:in 1887, asserts that every 7: 3060:Encyclopedia of Mathematics 1968: 1963:Brouwer fixed-point theorem 1567:Brouwer fixed point theorem 704:Brouwer fixed point theorem 265:in the plane is connected. 188:(1) and the restriction of 10: 3139: 2417:Richard Courant ( 2295:SurĂłwka, Wojciech (1993). 2151:. IEEE. pp. 245–256. 1915: 1397:History and further proofs 678:onto the unit sphere, the 354:is their common boundary. 281:in 1911, resulting in the 279:L. E. J. Brouwer 233:, consists of exactly two 2900:10.1007/s00153-007-0050-6 2273:10.1016/j.dam.2002.11.003 1527:Arthur Moritz Schoenflies 1386:{\displaystyle n\times n} 596:Jordan–Schönflies theorem 372:reduced integral homology 269:Proof and generalizations 2550:10.1216/RMJ-1975-5-2-225 2254:Ĺ lapal, J (April 2004). 1992: 1582:complete bipartite graph 1487:low-dimensional topology 161:that is not necessarily 3089:(PDF) by David B. Gauld 2781:10.2140/pjm.1971.36.219 2434:1. Jordan curve theorem 1717:{\displaystyle \delta } 1648:{\displaystyle \delta } 1628:{\displaystyle \delta } 1113:{\displaystyle (x',y')} 680:Alexander horned sphere 529:Mayer–Vietoris sequence 366:is homeomorphic to the 338:. Then the complement 2760:Narens, Louis (1971), 1924:computational geometry 1913: 1892:If the initial point ( 1865:If the initial point ( 1846: 1772: 1718: 1695: 1649: 1629: 1476: 1468: 1455: 1411:nowhere differentiable 1387: 1349: 1317: 1288: 1254: 1194: 1114: 1072: 1037: 927: 897: 883: 847: 818: 789: 760: 559:, who established the 514: 35: 3123:Theorems about curves 1953:Computational aspects 1864: 1847: 1773: 1719: 1696: 1650: 1630: 1549:non-standard analysis 1472: 1463: 1450: 1388: 1350: 1318: 1289: 1255: 1195: 1115: 1073: 1071:{\displaystyle (x,y)} 1038: 928: 926:{\displaystyle (x,y)} 895: 884: 848: 819: 790: 761: 515: 64:by the curve and an " 33: 3118:Theorems in topology 2997:10.1112/blms/12.1.34 2167:10.1109/lics.2007.48 1986:Quasi-Fuchsian group 1975:Denjoy–Riesz theorem 1819: 1736: 1708: 1659: 1639: 1619: 1413:curves, such as the 1371: 1330: 1298: 1269: 1204: 1124: 1082: 1050: 937: 905: 864: 828: 799: 770: 741: 393: 235:connected components 44:Jordan curve theorem 1808:reverse mathematics 1436:in his lectures on 293: —  257:of each component. 211: —  117:simple closed curve 2931:Thomassen, Carsten 2709:, pp. 587–594 2336:10.1007/BF00499625 1914: 1842: 1812:weak KĹ‘nig's lemma 1768: 1732:that the sequence 1714: 1691: 1645: 1625: 1565:A proof using the 1383: 1345: 1313: 1284: 1250: 1190: 1110: 1078:is connected with 1068: 1033: 933:is connected with 923: 898: 879: 843: 814: 785: 756: 686:homeomorphic to a 510: 505: 370:-sphere, then the 306:topological sphere 291: 209: 83:algebraic topology 36: 2614:Uspekhi Mat. Nauk 2586:978-0-19-502517-0 2504:978-3-95977-013-2 2358:Oswald Veblen 2176:978-0-7695-2908-0 1806:) showed that in 1523:Alfred Pringsheim 1515:Friedrich Hartogs 1503:Ludwig Bieberbach 646:is viewed as the 561:Alexander duality 498: 463: 406: 289: 249:), and the curve 207: 16:(Redirected from 3130: 3104: 3102: 3067: 3055:"Jordan theorem" 3042: 3025: 2999: 2990: 2970: 2957: 2926: 2878: 2848: 2823: 2800: 2783: 2756: 2710: 2708: 2693: 2683: 2670: 2626:Hales, Thomas C. 2621: 2611: 2598: 2569: 2552: 2521: 2515: 2509: 2508: 2496: 2472: 2466: 2465: 2463: 2462: 2456:wrf.ecse.rpi.edu 2448: 2442: 2441: 2439: 2428: 2422: 2415: 2409: 2408: 2393: 2387: 2382: 2376: 2371: 2365: 2355: 2349: 2347: 2319: 2313: 2312: 2292: 2286: 2285: 2275: 2266:(1–3): 231–251. 2251: 2245: 2244: 2230: 2224: 2223: 2187: 2181: 2180: 2160: 2144: 2138: 2137: 2101: 2095: 2089: 2083: 2082: 2072: 2064:Hales, Thomas C. 2060: 2054: 2053: 2017: 2011: 2005: 1944: 1940: 1908: 1907: 1902: 1901: 1885: 1884: 1875: 1874: 1851: 1849: 1848: 1843: 1841: 1840: 1835: 1834: 1814:over the system 1777: 1775: 1774: 1769: 1761: 1760: 1748: 1747: 1723: 1721: 1720: 1715: 1700: 1698: 1697: 1692: 1684: 1683: 1671: 1670: 1654: 1652: 1651: 1646: 1634: 1632: 1631: 1626: 1592:Thomassen (1992) 1491:complex analysis 1392: 1390: 1389: 1384: 1354: 1352: 1351: 1346: 1344: 1343: 1338: 1322: 1320: 1319: 1314: 1312: 1311: 1306: 1293: 1291: 1290: 1285: 1283: 1282: 1277: 1259: 1257: 1256: 1251: 1246: 1235: 1199: 1197: 1196: 1191: 1183: 1178: 1164: 1150: 1145: 1131: 1119: 1117: 1116: 1111: 1106: 1095: 1077: 1075: 1074: 1069: 1042: 1040: 1039: 1034: 932: 930: 929: 924: 888: 886: 885: 880: 878: 877: 872: 852: 850: 849: 844: 842: 841: 836: 823: 821: 820: 815: 813: 812: 807: 794: 792: 791: 786: 784: 783: 778: 765: 763: 762: 757: 755: 754: 749: 735:image processing 698:Discrete version 672:simply connected 519: 517: 516: 511: 509: 508: 499: 496: 464: 461: 439: 414: 413: 408: 407: 399: 386:are as follows: 313:+1)-dimensional 294: 212: 141:into the plane, 46:, formulated by 21: 3138: 3137: 3133: 3132: 3131: 3129: 3128: 3127: 3108: 3107: 3049: 3023:10.2307/1986378 2988:10.1.1.374.2903 2968: 2962:Tverberg, Helge 2947:10.2307/2324180 2821:10.2307/1986455 2730:10.2307/2323369 2724:(10): 641–643, 2706: 2703:Cours d'analyse 2698:Jordan, Camille 2681: 2638:(10): 882–894, 2609: 2603:Filippov, A. F. 2587: 2529: 2524: 2516: 2512: 2505: 2473: 2469: 2460: 2458: 2450: 2449: 2445: 2437: 2431:"V. Topology". 2430: 2429: 2425: 2416: 2412: 2394: 2390: 2383: 2379: 2372: 2368: 2356: 2352: 2320: 2316: 2293: 2289: 2252: 2248: 2231: 2227: 2198:(10): 882–894. 2188: 2184: 2177: 2145: 2141: 2118:10.2307/2320146 2112:(10): 818–827. 2102: 2098: 2090: 2086: 2070: 2061: 2057: 2034:10.2307/2303093 2018: 2014: 2006: 1999: 1995: 1971: 1955: 1942: 1938: 1920: 1905: 1904: 1899: 1894: 1893: 1891: 1882: 1881: 1872: 1867: 1866: 1859: 1836: 1824: 1823: 1822: 1820: 1817: 1816: 1756: 1752: 1743: 1739: 1737: 1734: 1733: 1709: 1706: 1705: 1679: 1675: 1666: 1662: 1660: 1657: 1656: 1640: 1637: 1636: 1620: 1617: 1616: 1605:polygonal chain 1600:Tverberg (1980) 1589: 1542:Tverberg (1980) 1538:Filippov (1950) 1519:BĂ©la KerĂ©kjártĂł 1507:Luitzen Brouwer 1495:J. W. Alexander 1459:Thomas C. Hales 1425:constructed by 1403:Bernard Bolzano 1399: 1372: 1369: 1368: 1361: 1339: 1334: 1333: 1331: 1328: 1327: 1307: 1302: 1301: 1299: 1296: 1295: 1278: 1273: 1272: 1270: 1267: 1266: 1239: 1228: 1205: 1202: 1201: 1179: 1171: 1160: 1146: 1138: 1127: 1125: 1122: 1121: 1099: 1088: 1083: 1080: 1079: 1051: 1048: 1047: 938: 935: 934: 906: 903: 902: 873: 868: 867: 865: 862: 861: 855:graph structure 837: 832: 831: 829: 826: 825: 808: 803: 802: 800: 797: 796: 779: 774: 773: 771: 768: 767: 750: 745: 744: 742: 739: 738: 731: 700: 682:is a subset of 557:J. W. Alexander 504: 503: 495: 493: 478: 477: 460: 443: 435: 428: 427: 409: 398: 397: 396: 394: 391: 390: 360:homology theory 358:The proof uses 356: 315:Euclidean space 292: 271: 259: 210: 109: 101:Thomas C. Hales 70:continuous path 28: 23: 22: 15: 12: 11: 5: 3136: 3126: 3125: 3120: 3106: 3105: 3090: 3084: 3078: 3068: 3048: 3047:External links 3045: 3044: 3043: 3004:Veblen, Oswald 3000: 2958: 2941:(2): 116–130, 2927: 2894:(5): 465–480, 2883: 2862:(4): 213–219, 2849: 2814:(1): 107–112, 2801: 2757: 2711: 2694: 2671: 2622: 2616:(in Russian), 2599: 2585: 2570: 2543:(2): 225–236, 2528: 2525: 2523: 2522: 2518:Maehara (1984) 2510: 2503: 2467: 2443: 2423: 2410: 2397:A. Schoenflies 2388: 2377: 2366: 2350: 2330:(3): 262–295. 2314: 2287: 2246: 2225: 2182: 2175: 2139: 2096: 2094:, p. 641. 2092:Maehara (1984) 2084: 2055: 2028:(5): 281–286. 2012: 1996: 1994: 1991: 1990: 1989: 1983: 1978: 1970: 1967: 1954: 1951: 1928:simple polygon 1916:Main article: 1897: 1870: 1858: 1855: 1839: 1833: 1830: 1827: 1767: 1764: 1759: 1755: 1751: 1746: 1742: 1713: 1690: 1687: 1682: 1678: 1674: 1669: 1665: 1644: 1624: 1596: 1595: 1587: 1576:A proof using 1574: 1571:Maehara (1984) 1563: 1556: 1547:A proof using 1545: 1434:Camille Jordan 1419:fractal curves 1415:Koch snowflake 1398: 1395: 1382: 1379: 1376: 1360: 1357: 1342: 1337: 1310: 1305: 1281: 1276: 1262: 1261: 1249: 1245: 1242: 1238: 1234: 1231: 1227: 1224: 1221: 1218: 1215: 1212: 1209: 1189: 1186: 1182: 1177: 1174: 1170: 1167: 1163: 1159: 1156: 1153: 1149: 1144: 1141: 1137: 1134: 1130: 1109: 1105: 1102: 1098: 1094: 1091: 1087: 1067: 1064: 1061: 1058: 1055: 1044: 1032: 1029: 1026: 1023: 1020: 1017: 1014: 1011: 1008: 1005: 1002: 999: 996: 993: 990: 987: 984: 981: 978: 975: 972: 969: 966: 963: 960: 957: 954: 951: 948: 945: 942: 922: 919: 916: 913: 910: 876: 871: 840: 835: 811: 806: 782: 777: 753: 748: 730: 727: 699: 696: 549:path connected 521: 520: 507: 502: 494: 492: 489: 486: 483: 480: 479: 476: 473: 470: 467: 462: or  459: 456: 453: 450: 447: 444: 442: 438: 434: 433: 431: 426: 423: 420: 417: 412: 405: 402: 287: 270: 267: 205: 135:continuous map 108: 105: 93:Camille Jordan 79:Tverberg (1980 48:Camille Jordan 26: 9: 6: 4: 3: 2: 3135: 3124: 3121: 3119: 3116: 3115: 3113: 3101: 3096: 3091: 3088: 3085: 3082: 3079: 3076: 3072: 3069: 3066: 3062: 3061: 3056: 3051: 3050: 3041: 3037: 3033: 3029: 3024: 3019: 3015: 3011: 3010: 3005: 3001: 2998: 2994: 2989: 2984: 2980: 2976: 2975: 2967: 2963: 2959: 2956: 2952: 2948: 2944: 2940: 2936: 2932: 2928: 2925: 2921: 2917: 2913: 2909: 2905: 2901: 2897: 2893: 2889: 2884: 2882: 2881:author's site 2877: 2873: 2869: 2865: 2861: 2857: 2856: 2850: 2847: 2843: 2839: 2835: 2831: 2827: 2822: 2817: 2813: 2809: 2808: 2802: 2799: 2795: 2791: 2787: 2782: 2777: 2773: 2769: 2768: 2763: 2758: 2755: 2751: 2747: 2743: 2739: 2735: 2731: 2727: 2723: 2719: 2718: 2712: 2705: 2704: 2699: 2695: 2691: 2687: 2680: 2676: 2675:Hales, Thomas 2672: 2669: 2665: 2661: 2657: 2653: 2649: 2645: 2641: 2637: 2633: 2632: 2627: 2623: 2619: 2615: 2608: 2604: 2600: 2596: 2592: 2588: 2582: 2578: 2577: 2571: 2568: 2564: 2560: 2556: 2551: 2546: 2542: 2538: 2537: 2531: 2530: 2519: 2514: 2506: 2500: 2495: 2490: 2486: 2482: 2478: 2471: 2457: 2453: 2447: 2436: 2435: 2427: 2420: 2414: 2406: 2402: 2398: 2392: 2386: 2385:Hales (2007b) 2381: 2375: 2374:Hales (2007b) 2370: 2363: 2359: 2354: 2345: 2341: 2337: 2333: 2329: 2325: 2318: 2310: 2306: 2302: 2298: 2291: 2283: 2279: 2274: 2269: 2265: 2261: 2257: 2250: 2242: 2241: 2236: 2229: 2221: 2217: 2213: 2209: 2205: 2201: 2197: 2193: 2186: 2178: 2172: 2168: 2164: 2159: 2154: 2150: 2143: 2135: 2131: 2127: 2123: 2119: 2115: 2111: 2107: 2100: 2093: 2088: 2080: 2076: 2069: 2065: 2059: 2051: 2047: 2043: 2039: 2035: 2031: 2027: 2023: 2016: 2009: 2008:Jordan (1887) 2004: 2002: 1997: 1987: 1984: 1982: 1981:Lakes of Wada 1979: 1976: 1973: 1972: 1966: 1964: 1960: 1959:PPAD-complete 1950: 1948: 1936: 1931: 1929: 1925: 1919: 1912: 1900: 1889: 1879: 1873: 1863: 1854: 1852: 1837: 1813: 1809: 1805: 1801: 1797: 1793: 1792:Hales (2007a) 1789: 1784: 1781: 1765: 1762: 1757: 1753: 1749: 1744: 1740: 1731: 1727: 1726:closed region 1711: 1703: 1688: 1685: 1680: 1676: 1672: 1667: 1663: 1642: 1622: 1614: 1610: 1606: 1601: 1593: 1590:was given by 1586: 1583: 1579: 1578:non-planarity 1575: 1572: 1568: 1564: 1561: 1557: 1554: 1553:Narens (1971) 1550: 1546: 1543: 1539: 1535: 1534: 1533: 1530: 1528: 1524: 1520: 1516: 1512: 1511:Arnaud Denjoy 1508: 1504: 1500: 1499:Louis Antoine 1496: 1492: 1488: 1483: 1481: 1475: 1471: 1467: 1462: 1460: 1454: 1449: 1447: 1446:Oswald Veblen 1443: 1439: 1438:real analysis 1435: 1430: 1428: 1427:Osgood (1903) 1424: 1420: 1416: 1412: 1408: 1404: 1394: 1380: 1377: 1374: 1365: 1356: 1340: 1324: 1308: 1279: 1243: 1240: 1236: 1232: 1229: 1222: 1216: 1213: 1210: 1187: 1184: 1175: 1172: 1168: 1165: 1157: 1154: 1151: 1142: 1139: 1135: 1132: 1103: 1100: 1096: 1092: 1089: 1062: 1059: 1056: 1045: 1027: 1024: 1021: 1018: 1015: 1009: 1003: 1000: 997: 994: 991: 985: 979: 976: 973: 970: 967: 961: 955: 952: 949: 946: 943: 917: 914: 911: 900: 899: 894: 890: 874: 858: 856: 838: 809: 780: 751: 736: 726: 722: 719: 717: 711: 709: 705: 695: 693: 689: 685: 681: 677: 674:, because it 673: 669: 665: 661: 657: 653: 649: 645: 641: 637: 633: 629: 625: 621: 617: 613: 609: 605: 601: 597: 592: 590: 586: 582: 578: 574: 570: 566: 562: 558: 554: 550: 546: 542: 538: 534: 530: 526: 500: 490: 484: 474: 471: 468: 465: 457: 454: 451: 448: 445: 440: 429: 424: 418: 410: 400: 389: 388: 387: 385: 381: 377: 373: 369: 365: 361: 355: 353: 349: 345: 341: 337: 333: 330: 328: 323: 319: 316: 312: 308: 307: 303:-dimensional 302: 298: 286: 284: 280: 276: 266: 264: 258: 256: 252: 248: 244: 240: 236: 232: 229: \  228: 224: 220: 216: 204: 201: 199: 195: 191: 187: 183: 179: 175: 170: 168: 164: 160: 156: 152: 148: 144: 140: 136: 133: 129: 126: 122: 119:in the plane 118: 114: 104: 102: 98: 97:Oswald Veblen 94: 91: 90:mathematician 86: 84: 80: 75: 71: 67: 63: 59: 55: 54: 49: 45: 41: 32: 19: 3058: 3016:(1): 83–98, 3013: 3007: 2981:(1): 34–38, 2978: 2972: 2938: 2934: 2891: 2887: 2859: 2853: 2811: 2805: 2771: 2765: 2721: 2715: 2702: 2689: 2685: 2635: 2629: 2620:(5): 173–176 2617: 2613: 2574: 2540: 2534: 2513: 2484: 2480: 2470: 2459:. Retrieved 2455: 2446: 2433: 2426: 2413: 2404: 2400: 2391: 2380: 2369: 2353: 2327: 2323: 2317: 2303:(7): 57–61. 2300: 2290: 2263: 2259: 2249: 2238: 2228: 2195: 2191: 2185: 2148: 2142: 2109: 2105: 2099: 2087: 2078: 2074: 2058: 2025: 2021: 2015: 1956: 1932: 1921: 1895: 1868: 1800:Mizar system 1788:formal proof 1785: 1779: 1729: 1701: 1597: 1584: 1531: 1484: 1477: 1473: 1469: 1464: 1456: 1451: 1441: 1431: 1400: 1366: 1362: 1325: 1263: 859: 732: 723: 720: 712: 701: 691: 683: 667: 663: 659: 655: 651: 643: 639: 635: 631: 627: 623: 619: 615: 611: 604:homeomorphic 599: 593: 588: 584: 580: 576: 572: 568: 552: 544: 540: 536: 532: 524: 522: 383: 379: 375: 367: 363: 357: 351: 347: 343: 339: 335: 331: 326: 321: 317: 310: 304: 300: 296: 288: 282: 272: 262: 260: 250: 246: 242: 230: 226: 218: 214: 206: 202: 197: 193: 189: 185: 181: 177: 173: 171: 154: 150: 146: 142: 127: 120: 116: 113:Jordan curve 112: 110: 103:and others. 87: 53:Jordan curve 51: 43: 37: 2774:: 219–229, 2348:See p. 285. 1857:Application 708:game of Hex 648:unit circle 275:H. Lebesgue 221:. Then its 159:plane curve 3112:Categories 2838:34.0533.02 2527:References 2461:2021-07-18 2407:: 157–160. 1786:The first 1780:presumably 1702:presumably 1421:, or even 1417:and other 527:using the 374:groups of 223:complement 180:such that 155:Jordan arc 18:Jordan arc 3100:1404.0556 3065:EMS Press 2983:CiteSeerX 2908:0933-5846 2830:0002-9947 2790:0030-8730 2738:0002-9890 2677:(2007b), 2652:0002-9890 2559:0035-7596 2282:0166-218X 2212:0002-9890 2158:1002.2954 2126:0002-9890 1796:HOL Light 1766:… 1754:δ 1741:δ 1712:δ 1689:… 1677:δ 1664:δ 1643:δ 1623:δ 1457:However, 1378:× 1223:≠ 1185:≤ 1169:− 1152:≤ 1136:− 1025:− 971:− 718:theorem. 608:unit disk 497:otherwise 455:− 404:~ 167:algebraic 132:injective 60:" region 2964:(1980), 2924:33627222 2700:(1887), 2605:(1950), 2066:(2007). 1969:See also 1609:open set 1407:polygons 1244:′ 1233:′ 1176:′ 1143:′ 1104:′ 1093:′ 716:discrete 676:retracts 642:, where 309:in the ( 255:boundary 247:exterior 243:interior 66:exterior 58:interior 40:topology 3040:1500697 3032:1986378 2955:2324180 2916:2321588 2876:3257011 2846:1986455 2798:0276940 2754:0769530 2746:2323369 2660:2363054 2595:6450129 2567:0410701 2360: ( 2344:0446838 2309:1271184 2240:YouTube 2134:2320146 2050:0006516 2042:2303093 1876:) of a 1794:in the 1613:closure 1580:of the 1461:wrote: 567:subset 565:compact 531:. When 329:-sphere 290:Theorem 253:is the 239:bounded 208:Theorem 123:is the 74:theorem 62:bounded 3038:  3030:  2985:  2953:  2922:  2914:  2906:  2874:  2844:  2836:  2828:  2796:  2788:  2752:  2744:  2736:  2668:887392 2666:  2658:  2650:  2593:  2583:  2565:  2557:  2501:  2342:  2307:  2280:  2220:887392 2218:  2210:  2173:  2132:  2124:  2048:  2040:  1525:, and 1453:given. 1200:, and 688:sphere 652:ψ 632:φ 579:is an 299:be an 184:(0) = 163:smooth 139:circle 130:of an 42:, the 3095:arXiv 3075:Mizar 3028:JSTOR 2969:(PDF) 2951:JSTOR 2920:S2CID 2872:S2CID 2842:JSTOR 2742:JSTOR 2707:(PDF) 2682:(PDF) 2664:S2CID 2610:(PDF) 2438:(PDF) 2216:S2CID 2153:arXiv 2130:JSTOR 2071:(PDF) 2038:JSTOR 1993:Notes 1730:prove 664:false 622:with 334:into 241:(the 176:: → 137:of a 125:image 115:or a 2904:ISSN 2826:ISSN 2786:ISSN 2734:ISSN 2692:(23) 2648:ISSN 2591:OCLC 2581:ISBN 2555:ISSN 2499:ISBN 2419:1978 2362:1905 2278:ISSN 2208:ISSN 2171:ISBN 2122:ISSN 1911:odd. 1888:even 1804:2007 1560:1975 1540:and 1489:and 1120:iff 602:are 587:(or 295:Let 277:and 213:Let 165:nor 153:. A 3073:in 3018:doi 2993:doi 2943:doi 2896:doi 2864:doi 2834:JFM 2816:doi 2776:doi 2726:doi 2640:doi 2636:114 2545:doi 2489:doi 2332:doi 2268:doi 2264:139 2200:doi 2196:114 2163:doi 2114:doi 2030:doi 1947:odd 1945:is 1935:ray 1922:In 1878:ray 1588:3,3 1569:by 1551:by 889:: 824:if 733:In 670:is 571:of 346:in 342:of 263:arc 38:In 3114:: 3063:, 3057:, 3036:MR 3034:, 3026:, 3012:, 2991:, 2979:12 2977:, 2971:, 2949:, 2939:99 2937:, 2918:, 2912:MR 2910:, 2902:, 2892:46 2890:, 2879:. 2870:, 2858:, 2840:, 2832:, 2824:, 2810:, 2794:MR 2792:, 2784:, 2772:36 2770:, 2764:, 2750:MR 2748:, 2740:, 2732:, 2722:91 2720:, 2690:10 2688:, 2684:, 2662:, 2656:MR 2654:, 2646:, 2634:, 2612:, 2589:. 2563:MR 2561:, 2553:, 2539:, 2497:. 2485:55 2479:. 2454:. 2405:33 2403:. 2340:MR 2338:. 2328:17 2326:. 2305:MR 2299:. 2276:. 2262:. 2258:. 2237:. 2214:. 2206:. 2194:. 2169:. 2161:. 2128:. 2120:. 2110:86 2108:. 2079:10 2077:. 2046:MR 2044:. 2036:. 2026:49 2024:. 2000:^ 1949:. 1930:. 1853:. 1562:). 1529:. 1521:, 1517:, 1513:, 1509:, 1505:, 1501:, 1497:, 1429:. 857:. 658:→ 654:: 638:→ 634:: 535:= 382:\ 378:= 285:. 225:, 169:. 149:→ 145:: 111:A 3103:. 3097:: 3077:. 3020:: 3014:6 2995:: 2945:: 2898:: 2866:: 2860:5 2818:: 2812:4 2778:: 2728:: 2642:: 2618:5 2597:. 2547:: 2541:5 2520:. 2507:. 2491:: 2464:. 2421:) 2364:) 2346:. 2334:: 2311:. 2284:. 2270:: 2243:. 2222:. 2202:: 2179:. 2165:: 2155:: 2136:. 2116:: 2052:. 2032:: 2010:. 1943:n 1939:n 1906:B 1898:b 1896:p 1890:. 1883:A 1871:a 1869:p 1838:0 1832:A 1829:C 1826:R 1763:, 1758:2 1750:, 1745:1 1686:, 1681:2 1673:, 1668:1 1594:. 1585:K 1573:. 1555:. 1544:. 1381:n 1375:n 1341:2 1336:Z 1309:2 1304:Z 1280:2 1275:R 1260:. 1248:) 1241:y 1237:, 1230:x 1226:( 1220:) 1217:y 1214:, 1211:x 1208:( 1188:1 1181:| 1173:y 1166:y 1162:| 1158:, 1155:1 1148:| 1140:x 1133:x 1129:| 1108:) 1101:y 1097:, 1090:x 1086:( 1066:) 1063:y 1060:, 1057:x 1054:( 1043:. 1031:) 1028:1 1022:y 1019:, 1016:x 1013:( 1010:, 1007:) 1004:1 1001:+ 998:y 995:, 992:x 989:( 986:, 983:) 980:y 977:, 974:1 968:x 965:( 962:, 959:) 956:y 953:, 950:1 947:+ 944:x 941:( 921:) 918:y 915:, 912:x 909:( 875:2 870:Z 839:2 834:Z 810:2 805:Z 781:2 776:R 752:2 747:Z 692:R 684:R 668:R 660:R 656:R 644:S 640:R 636:S 628:A 624:A 620:P 616:A 612:P 600:R 589:S 585:R 581:n 577:X 573:R 569:X 553:X 545:Y 541:Y 537:k 533:n 525:k 501:. 491:, 488:} 485:0 482:{ 475:, 472:n 469:= 466:q 458:k 452:n 449:= 446:q 441:, 437:Z 430:{ 425:= 422:) 419:Y 416:( 411:q 401:H 384:X 380:R 376:Y 368:k 364:X 352:X 348:R 344:X 340:Y 336:R 332:S 327:n 322:n 320:( 318:R 311:n 301:n 297:X 251:C 231:C 227:R 219:R 215:C 198:C 194:C 190:φ 186:φ 182:φ 178:R 174:φ 151:R 147:S 143:φ 128:C 121:R 77:( 20:)

Index

Jordan arc

topology
Camille Jordan
Jordan curve
interior
bounded
exterior
continuous path
theorem
Tverberg (1980
algebraic topology
mathematician
Camille Jordan
Oswald Veblen
Thomas C. Hales
image
injective
continuous map
circle
plane curve
smooth
algebraic
complement
connected components
bounded
boundary
H. Lebesgue
L. E. J. Brouwer
topological sphere

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