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Subspace topology

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The distinction between a set and a topological space is often blurred notationally, for convenience, which can be a source of confusion when one first encounters these definitions. Thus, whenever
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is equipped with the subspace topology then it is a topological space in its own right, and is called a
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This property is characteristic in the sense that it can be used to define the subspace topology on
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is continuous. The open sets in this topology are precisely the ones of the form
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We list some further properties of the subspace topology. In the following let
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Pinoli, Jean-Charles (June 2014), "The Geometric and Topological Framework",
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as the topological spaces, related as discussed above. So phrases such as "
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do not have the discrete topology ({0} for example is not an open set in
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implies its subspaces have that property, then we say the property is
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The subspace topology has the following characteristic property. Let
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is both open and closed as a subset of itself but not as a subset of
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with the same topology. In other words the subspace topology that
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to this subset coincides with subspace topology for this subset.
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Alternatively we can define the subspace topology for a subset
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subsets (which happen also to be closed), and is therefore a
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Mathematical Foundations of Image Processing and Analysis 2
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is considered to be endowed with the subspace topology.
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be the inclusion map. Then for any topological space
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is a topological space, then the unadorned symbols "
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Submanifolds, p. 59 2881: 1768: 1732: 1710: 1640: 1604: 1567: 1542: 1520: 1447: 1425: 1403: 1381: 1359: 1327: 1293: 482:{\displaystyle \iota :S\hookrightarrow X} 2718:{\displaystyle B_{S}=\{U\cap S:U\in B\}} 2337:is the same as the one it inherits from 1596:= [0, 1) be a subspace of the real line 1581:, ∪ is composed of two disjoint 1231:, in the sense used above; that is: (i) 14: 3030: 2923: 2761:Preservation of topological properties 2748:The topology induced on a subset of a 2055:is continuous then the restriction to 726:(also with the subspace topology) and 2877: 2875: 2873: 2554:{\displaystyle X\setminus S\in \tau } 989:" can often be used to refer both to 2765:If a topological space having some 2174:are precisely the intersections of 1417:because there is no open subset of 24: 2870: 1947: 1477:are rational, then the intervals ( 25: 3054: 2539: 284:is open in the subspace topology 563:. Then the subspace topology on 2785:space is completely metrizable. 2601:if and only if it is closed in 1724:(as there is no open subset of 2917: 2138: 2132: 2126: 2094: 2039: 1899: 1847: 1218: 1206: 1186: 1167: 1107: 1095: 1075: 1056: 936: 924: 872: 635:{\displaystyle \iota ^{-1}(U)} 629: 623: 473: 391: 379: 335: 323: 118: 106: 13: 1: 2954: 2466:if and only if it is open in 1786: 1315:The subspace topology of the 1192:{\displaystyle (S,\tau _{S})} 1081:{\displaystyle (S,\tau _{S})} 1029:considered as two subsets of 94: 3017:, Dover Publications (2004) 1775:{\displaystyle \mathbb {R} } 1739:{\displaystyle \mathbb {R} } 1717:{\displaystyle \mathbb {R} } 1647:{\displaystyle \mathbb {R} } 1611:{\displaystyle \mathbb {R} } 1574:{\displaystyle \mathbb {R} } 1549:{\displaystyle \mathbb {R} } 1527:{\displaystyle \mathbb {R} } 1454:{\displaystyle \mathbb {Q} } 1432:{\displaystyle \mathbb {R} } 1410:{\displaystyle \mathbb {Q} } 1388:{\displaystyle \mathbb {R} } 1373:considered as a subspace of 1366:{\displaystyle \mathbb {Q} } 1334:{\displaystyle \mathbb {R} } 1300:{\displaystyle \mathbb {R} } 7: 2981:Counterexamples in Topology 2840: 2795:Every closed subspace of a 2144:{\displaystyle f:X\to f(X)} 1311:with their usual topology. 1280: 10: 3059: 2934:10.1002/9781118984574.ch26 2419:{\displaystyle S\in \tau } 1512:The set as a subspace of 1250:{\displaystyle S\in \tau } 841:. Likewise it is called a 99:Given a topological space 29: 2928:, Wiley, pp. 57–69, 2882:tom Dieck, Tammo (2008), 2788:Every open subspace of a 1224:{\displaystyle (X,\tau )} 1113:{\displaystyle (X,\tau )} 942:{\displaystyle (X,\tau )} 499:More generally, suppose 397:{\displaystyle (X,\tau )} 341:{\displaystyle (X,\tau )} 124:{\displaystyle (X,\tau )} 67:which is equipped with a 2863: 2509:is a closed subspace of 2103:{\displaystyle f:X\to Y} 2048:{\displaystyle f:X\to Y} 1938:{\displaystyle i\circ f} 1908:{\displaystyle f:Z\to Y} 1856:{\displaystyle i:Y\to X} 1509:is both open and closed. 1439:whose intersection with 1160:" are used to mean that 2967:, Addison-Wesley (1966) 2380:is an open subspace of 1199:is an open subspace of 543:to a topological space 2976:Seebach, J. Arthur Jr. 2739: 2719: 2662: 2638: 2615: 2595: 2575: 2555: 2523: 2503: 2480: 2460: 2440: 2420: 2394: 2374: 2351: 2331: 2311: 2291: 2277:is also a subspace of 2271: 2251: 2231: 2208: 2188: 2168: 2145: 2104: 2069: 2049: 2013: 1993: 1970: 1953: 1939: 1909: 1877: 1857: 1825: 1805: 1776: 1740: 1718: 1648: 1612: 1575: 1550: 1528: 1455: 1433: 1411: 1389: 1367: 1335: 1301: 1271: 1251: 1225: 1193: 1154: 1134: 1114: 1082: 1043: 1023: 1003: 983: 963: 943: 911: 891: 859: 858:{\displaystyle \iota } 835: 815: 791: 790:{\displaystyle \iota } 767: 740: 739:{\displaystyle \iota } 720: 696: 676: 656: 636: 597: 596:{\displaystyle \iota } 577: 557: 537: 513: 512:{\displaystyle \iota } 483: 441: 421: 398: 362: 342: 306: 278: 255: 192: 168: 148: 125: 2813:is weakly hereditary. 2783:completely metrizable 2740: 2720: 2663: 2639: 2616: 2596: 2576: 2556: 2524: 2504: 2481: 2461: 2441: 2421: 2395: 2375: 2352: 2332: 2312: 2292: 2272: 2252: 2232: 2209: 2189: 2169: 2146: 2105: 2070: 2050: 2014: 1994: 1971: 1951: 1940: 1910: 1878: 1858: 1826: 1806: 1777: 1741: 1719: 1649: 1613: 1576: 1551: 1529: 1456: 1434: 1412: 1390: 1368: 1336: 1302: 1272: 1252: 1226: 1194: 1155: 1135: 1115: 1083: 1044: 1024: 1004: 984: 964: 944: 912: 892: 860: 836: 816: 792: 768: 748:topological embedding 741: 721: 697: 677: 657: 637: 598: 578: 558: 538: 514: 484: 442: 422: 399: 363: 343: 307: 279: 264:That is, a subset of 256: 193: 169: 149: 126: 71:induced from that of 41:and related areas of 2824:totally disconnected 2767:topological property 2729: 2672: 2652: 2628: 2605: 2585: 2565: 2561:). Then a subset of 2533: 2513: 2493: 2470: 2450: 2430: 2426:). Then a subset of 2404: 2384: 2364: 2341: 2321: 2301: 2281: 2261: 2241: 2221: 2198: 2194:with closed sets in 2178: 2158: 2114: 2082: 2059: 2027: 2003: 1983: 1960: 1923: 1887: 1867: 1835: 1815: 1795: 1764: 1728: 1706: 1636: 1600: 1563: 1538: 1516: 1443: 1421: 1399: 1377: 1355: 1323: 1289: 1261: 1235: 1203: 1164: 1144: 1140:an open subspace of 1124: 1092: 1053: 1033: 1013: 993: 973: 953: 921: 901: 881: 849: 825: 805: 781: 757: 730: 710: 686: 666: 646: 607: 587: 567: 547: 527: 503: 461: 431: 411: 376: 352: 320: 296: 268: 205: 182: 158: 138: 103: 2858:direct sum topology 2834:second countability 2752:by restricting the 2154:The closed sets in 2110:is continuous then 1319:, as a subspace of 18:Subspace (topology) 3013:Willard, Stephen. 2972:Steen, Lynn Arthur 2885:Algebraic topology 2830:First countability 2735: 2715: 2658: 2634: 2611: 2591: 2571: 2551: 2519: 2499: 2476: 2456: 2436: 2416: 2390: 2370: 2347: 2327: 2307: 2287: 2267: 2247: 2227: 2204: 2184: 2164: 2141: 2100: 2065: 2045: 2009: 1989: 1966: 1954: 1935: 1919:the composite map 1905: 1873: 1853: 1821: 1801: 1772: 1736: 1714: 1698:, 1) is closed in 1644: 1608: 1587:disconnected space 1571: 1556:it is only closed. 1546: 1524: 1451: 1429: 1407: 1385: 1363: 1331: 1297: 1285:In the following, 1267: 1247: 1221: 1189: 1150: 1130: 1110: 1078: 1039: 1019: 999: 979: 959: 939: 907: 887: 855: 831: 811: 787: 763: 736: 716: 692: 672: 652: 632: 593: 573: 553: 533: 509: 479: 437: 417: 394: 358: 338: 302: 274: 251: 188: 164: 144: 121: 27:Inherited topology 2999:978-0-486-68735-3 2961:Bourbaki, Nicolas 2903:978-3-03719-048-7 2817:Total boundedness 2792:is a Baire space. 2775:weakly hereditary 2738:{\displaystyle S} 2661:{\displaystyle X} 2637:{\displaystyle B} 2614:{\displaystyle X} 2594:{\displaystyle S} 2574:{\displaystyle S} 2522:{\displaystyle X} 2502:{\displaystyle S} 2479:{\displaystyle X} 2459:{\displaystyle S} 2439:{\displaystyle S} 2393:{\displaystyle X} 2373:{\displaystyle S} 2350:{\displaystyle X} 2330:{\displaystyle S} 2310:{\displaystyle A} 2290:{\displaystyle X} 2270:{\displaystyle A} 2250:{\displaystyle S} 2237:is a subspace of 2230:{\displaystyle A} 2207:{\displaystyle X} 2187:{\displaystyle S} 2167:{\displaystyle S} 2068:{\displaystyle S} 2012:{\displaystyle X} 1999:be a subspace of 1992:{\displaystyle S} 1969:{\displaystyle Y} 1876:{\displaystyle Z} 1824:{\displaystyle X} 1811:be a subspace of 1804:{\displaystyle Y} 1559:As a subspace of 1343:discrete topology 1270:{\displaystyle S} 1153:{\displaystyle X} 1133:{\displaystyle S} 1042:{\displaystyle X} 1022:{\displaystyle X} 1002:{\displaystyle S} 982:{\displaystyle X} 962:{\displaystyle S} 910:{\displaystyle X} 890:{\displaystyle S} 845:if the injection 834:{\displaystyle X} 814:{\displaystyle S} 777:if the injection 766:{\displaystyle S} 719:{\displaystyle X} 695:{\displaystyle S} 675:{\displaystyle X} 655:{\displaystyle U} 576:{\displaystyle S} 556:{\displaystyle X} 536:{\displaystyle S} 449:coarsest topology 440:{\displaystyle X} 420:{\displaystyle S} 361:{\displaystyle S} 305:{\displaystyle S} 277:{\displaystyle S} 191:{\displaystyle S} 176:subspace topology 167:{\displaystyle X} 147:{\displaystyle S} 81:relative topology 77:subspace topology 51:topological space 16:(Redirected from 3050: 3043:General topology 3015:General Topology 3010: 2948: 2946: 2921: 2915: 2914: 2879: 2853:product topology 2846:the dual notion 2744: 2742: 2741: 2736: 2724: 2722: 2721: 2716: 2684: 2683: 2667: 2665: 2664: 2659: 2643: 2641: 2640: 2635: 2620: 2618: 2617: 2612: 2600: 2598: 2597: 2592: 2580: 2578: 2577: 2572: 2560: 2558: 2557: 2552: 2528: 2526: 2525: 2520: 2508: 2506: 2505: 2500: 2485: 2483: 2482: 2477: 2465: 2463: 2462: 2457: 2445: 2443: 2442: 2437: 2425: 2423: 2422: 2417: 2399: 2397: 2396: 2391: 2379: 2377: 2376: 2371: 2356: 2354: 2353: 2348: 2336: 2334: 2333: 2328: 2316: 2314: 2313: 2308: 2296: 2294: 2293: 2288: 2276: 2274: 2273: 2268: 2256: 2254: 2253: 2248: 2236: 2234: 2233: 2228: 2213: 2211: 2210: 2205: 2193: 2191: 2190: 2185: 2173: 2171: 2170: 2165: 2150: 2148: 2147: 2142: 2109: 2107: 2106: 2101: 2074: 2072: 2071: 2066: 2054: 2052: 2051: 2046: 2018: 2016: 2015: 2010: 1998: 1996: 1995: 1990: 1975: 1973: 1972: 1967: 1945:is continuous. 1944: 1942: 1941: 1936: 1914: 1912: 1911: 1906: 1882: 1880: 1879: 1874: 1862: 1860: 1859: 1854: 1830: 1828: 1827: 1822: 1810: 1808: 1807: 1802: 1781: 1779: 1778: 1773: 1771: 1755: 1754: 1750: 1745: 1743: 1742: 1737: 1735: 1723: 1721: 1720: 1715: 1713: 1697: 1696: 1692: 1687: 1686: 1682: 1673: 1672: 1668: 1663: 1662: 1658: 1653: 1651: 1650: 1645: 1643: 1627: 1626: 1622: 1617: 1615: 1614: 1609: 1607: 1580: 1578: 1577: 1572: 1570: 1555: 1553: 1552: 1547: 1545: 1533: 1531: 1530: 1525: 1523: 1460: 1458: 1457: 1452: 1450: 1438: 1436: 1435: 1430: 1428: 1416: 1414: 1413: 1408: 1406: 1394: 1392: 1391: 1386: 1384: 1372: 1370: 1369: 1364: 1362: 1350:rational numbers 1340: 1338: 1337: 1332: 1330: 1306: 1304: 1303: 1298: 1296: 1276: 1274: 1273: 1268: 1256: 1254: 1253: 1248: 1230: 1228: 1227: 1222: 1198: 1196: 1195: 1190: 1185: 1184: 1159: 1157: 1156: 1151: 1139: 1137: 1136: 1131: 1119: 1117: 1116: 1111: 1087: 1085: 1084: 1079: 1074: 1073: 1048: 1046: 1045: 1040: 1028: 1026: 1025: 1020: 1008: 1006: 1005: 1000: 988: 986: 985: 980: 968: 966: 965: 960: 948: 946: 945: 940: 916: 914: 913: 908: 896: 894: 893: 888: 864: 862: 861: 856: 840: 838: 837: 832: 820: 818: 817: 812: 796: 794: 793: 788: 772: 770: 769: 764: 745: 743: 742: 737: 725: 723: 722: 717: 706:to its image in 701: 699: 698: 693: 681: 679: 678: 673: 661: 659: 658: 653: 641: 639: 638: 633: 622: 621: 602: 600: 599: 594: 582: 580: 579: 574: 562: 560: 559: 554: 542: 540: 539: 534: 518: 516: 515: 510: 488: 486: 485: 480: 446: 444: 443: 438: 426: 424: 423: 418: 403: 401: 400: 395: 367: 365: 364: 359: 347: 345: 344: 339: 311: 309: 308: 303: 283: 281: 280: 275: 260: 258: 257: 252: 217: 216: 197: 195: 194: 189: 173: 171: 170: 165: 153: 151: 150: 145: 130: 128: 127: 122: 85:induced topology 32:Initial topology 21: 3058: 3057: 3053: 3052: 3051: 3049: 3048: 3047: 3028: 3027: 3000: 2990:Springer-Verlag 2957: 2952: 2951: 2944: 2922: 2918: 2904: 2880: 2871: 2866: 2843: 2836:are hereditary. 2804:Hausdorff space 2763: 2730: 2727: 2726: 2725:is a basis for 2679: 2675: 2673: 2670: 2669: 2653: 2650: 2649: 2629: 2626: 2625: 2606: 2603: 2602: 2586: 2583: 2582: 2566: 2563: 2562: 2534: 2531: 2530: 2514: 2511: 2510: 2494: 2491: 2490: 2471: 2468: 2467: 2451: 2448: 2447: 2431: 2428: 2427: 2405: 2402: 2401: 2385: 2382: 2381: 2365: 2362: 2361: 2342: 2339: 2338: 2322: 2319: 2318: 2302: 2299: 2298: 2282: 2279: 2278: 2262: 2259: 2258: 2242: 2239: 2238: 2222: 2219: 2218: 2199: 2196: 2195: 2179: 2176: 2175: 2159: 2156: 2155: 2115: 2112: 2111: 2083: 2080: 2079: 2060: 2057: 2056: 2028: 2025: 2024: 2004: 2001: 2000: 1984: 1981: 1980: 1961: 1958: 1957: 1924: 1921: 1920: 1888: 1885: 1884: 1868: 1865: 1864: 1836: 1833: 1832: 1816: 1813: 1812: 1796: 1793: 1792: 1789: 1767: 1765: 1762: 1761: 1752: 1748: 1747: 1731: 1729: 1726: 1725: 1709: 1707: 1704: 1703: 1694: 1690: 1689: 1684: 1680: 1679: 1678:results in [0, 1670: 1666: 1665: 1660: 1656: 1655: 1639: 1637: 1634: 1633: 1624: 1620: 1619: 1603: 1601: 1598: 1597: 1566: 1564: 1561: 1560: 1541: 1539: 1536: 1535: 1519: 1517: 1514: 1513: 1446: 1444: 1441: 1440: 1424: 1422: 1419: 1418: 1402: 1400: 1397: 1396: 1380: 1378: 1375: 1374: 1358: 1356: 1353: 1352: 1326: 1324: 1321: 1320: 1317:natural numbers 1307:represents the 1292: 1290: 1287: 1286: 1283: 1262: 1259: 1258: 1236: 1233: 1232: 1204: 1201: 1200: 1180: 1176: 1165: 1162: 1161: 1145: 1142: 1141: 1125: 1122: 1121: 1093: 1090: 1089: 1069: 1065: 1054: 1051: 1050: 1034: 1031: 1030: 1014: 1011: 1010: 994: 991: 990: 974: 971: 970: 954: 951: 950: 922: 919: 918: 902: 899: 898: 897:is a subset of 882: 879: 878: 875: 850: 847: 846: 843:closed subspace 826: 823: 822: 806: 803: 802: 782: 779: 778: 758: 755: 754: 731: 728: 727: 711: 708: 707: 687: 684: 683: 667: 664: 663: 647: 644: 643: 614: 610: 608: 605: 604: 588: 585: 584: 568: 565: 564: 548: 545: 544: 528: 525: 524: 504: 501: 500: 462: 459: 458: 432: 429: 428: 412: 409: 408: 377: 374: 373: 353: 350: 349: 321: 318: 317: 297: 294: 293: 269: 266: 265: 212: 208: 206: 203: 202: 183: 180: 179: 159: 156: 155: 139: 136: 135: 104: 101: 100: 97: 35: 28: 23: 22: 15: 12: 11: 5: 3056: 3046: 3045: 3040: 3026: 3025: 3011: 2998: 2968: 2956: 2953: 2950: 2949: 2942: 2916: 2902: 2868: 2867: 2865: 2862: 2861: 2860: 2855: 2850: 2848:quotient space 2842: 2839: 2838: 2837: 2827: 2826:is hereditary. 2820: 2819:is hereditary. 2814: 2807: 2806:is hereditary. 2800: 2793: 2786: 2762: 2759: 2758: 2757: 2746: 2734: 2714: 2711: 2708: 2705: 2702: 2699: 2696: 2693: 2690: 2687: 2682: 2678: 2657: 2633: 2622: 2610: 2590: 2570: 2550: 2547: 2544: 2541: 2538: 2518: 2498: 2487: 2475: 2455: 2435: 2415: 2412: 2409: 2389: 2369: 2358: 2346: 2326: 2317:inherits from 2306: 2286: 2266: 2246: 2226: 2215: 2203: 2183: 2163: 2152: 2151:is continuous. 2140: 2137: 2134: 2131: 2128: 2125: 2122: 2119: 2099: 2096: 2093: 2090: 2087: 2076: 2075:is continuous. 2064: 2044: 2041: 2038: 2035: 2032: 2008: 1988: 1965: 1934: 1931: 1928: 1917:if and only if 1915:is continuous 1904: 1901: 1898: 1895: 1892: 1872: 1852: 1849: 1846: 1843: 1840: 1820: 1800: 1788: 1785: 1784: 1783: 1770: 1734: 1712: 1688:)). Likewise [ 1642: 1606: 1590: 1569: 1557: 1544: 1522: 1510: 1461:can result in 1449: 1427: 1405: 1383: 1361: 1346: 1329: 1295: 1282: 1279: 1266: 1246: 1243: 1240: 1220: 1217: 1214: 1211: 1208: 1188: 1183: 1179: 1175: 1172: 1169: 1149: 1129: 1109: 1106: 1103: 1100: 1097: 1077: 1072: 1068: 1064: 1061: 1058: 1049:, and also to 1038: 1018: 998: 978: 958: 938: 935: 932: 929: 926: 906: 886: 874: 871: 854: 830: 810: 786: 762: 735: 715: 691: 671: 651: 631: 628: 625: 620: 617: 613: 592: 572: 552: 532: 508: 490: 489: 478: 475: 472: 469: 466: 451:for which the 436: 416: 393: 390: 387: 384: 381: 357: 337: 334: 331: 328: 325: 301: 286:if and only if 273: 262: 261: 250: 247: 244: 241: 238: 235: 232: 229: 226: 223: 220: 215: 211: 198:is defined by 187: 163: 143: 120: 117: 114: 111: 108: 96: 93: 89:trace topology 26: 9: 6: 4: 3: 2: 3055: 3044: 3041: 3039: 3036: 3035: 3033: 3024: 3023:0-486-43479-6 3020: 3016: 3012: 3009: 3005: 3001: 2995: 2991: 2987: 2983: 2982: 2977: 2973: 2969: 2966: 2962: 2959: 2958: 2945: 2943:9781118984574 2939: 2935: 2931: 2927: 2920: 2913: 2909: 2905: 2899: 2895: 2891: 2887: 2886: 2878: 2876: 2874: 2869: 2859: 2856: 2854: 2851: 2849: 2845: 2844: 2835: 2831: 2828: 2825: 2821: 2818: 2815: 2812: 2808: 2805: 2801: 2798: 2797:compact space 2794: 2791: 2787: 2784: 2780: 2779: 2778: 2776: 2772: 2768: 2755: 2751: 2747: 2732: 2709: 2706: 2703: 2700: 2697: 2694: 2691: 2685: 2680: 2676: 2655: 2647: 2631: 2623: 2608: 2588: 2581:is closed in 2568: 2548: 2545: 2542: 2536: 2516: 2496: 2488: 2473: 2453: 2433: 2413: 2410: 2407: 2387: 2367: 2359: 2344: 2324: 2304: 2284: 2264: 2244: 2224: 2216: 2201: 2181: 2161: 2153: 2135: 2129: 2123: 2120: 2117: 2097: 2091: 2088: 2085: 2077: 2062: 2042: 2036: 2033: 2030: 2022: 2021: 2020: 2006: 1986: 1977: 1963: 1950: 1946: 1932: 1929: 1926: 1918: 1902: 1896: 1893: 1890: 1870: 1850: 1844: 1841: 1838: 1818: 1798: 1759: 1701: 1677: 1631: 1628:) is open in 1595: 1591: 1588: 1584: 1558: 1511: 1508: 1504: 1500: 1496: 1492: 1488: 1484: 1480: 1476: 1472: 1468: 1464: 1351: 1347: 1344: 1318: 1314: 1313: 1312: 1310: 1278: 1264: 1244: 1241: 1238: 1215: 1212: 1209: 1181: 1177: 1173: 1170: 1147: 1127: 1104: 1101: 1098: 1070: 1066: 1062: 1059: 1036: 1016: 996: 976: 956: 933: 930: 927: 904: 884: 870: 868: 852: 844: 828: 808: 800: 784: 776: 775:open subspace 773:is called an 760: 751: 749: 733: 713: 705: 689: 669: 649: 626: 618: 615: 611: 590: 570: 550: 530: 522: 506: 497: 495: 476: 470: 467: 464: 457: 456: 455: 454: 453:inclusion map 450: 434: 414: 405: 388: 385: 382: 371: 355: 332: 329: 326: 315: 299: 291: 287: 271: 248: 242: 239: 236: 233: 230: 227: 224: 218: 213: 209: 201: 200: 199: 185: 177: 161: 141: 134: 115: 112: 109: 92: 90: 86: 82: 78: 74: 70: 66: 62: 59: 55: 52: 48: 44: 40: 33: 19: 3014: 2979: 2964: 2925: 2919: 2884: 2811:normal space 2774: 2770: 2764: 2750:metric space 1978: 1955: 1790: 1757: 1699: 1675: 1629: 1593: 1582: 1506: 1502: 1498: 1494: 1490: 1486: 1482: 1478: 1474: 1470: 1462: 1309:real numbers 1284: 876: 842: 774: 752: 746:is called a 704:homeomorphic 498: 491: 406: 369: 290:intersection 263: 175: 98: 88: 84: 80: 76: 72: 64: 60: 53: 46: 36: 2894:10.4171/048 2799:is compact. 2790:Baire space 2446:is open in 1702:but not in 1632:but not in 1618:. Then [0, 1257:; and (ii) 873:Terminology 821:is open in 753:A subspace 523:from a set 75:called the 43:mathematics 3032:Categories 2955:References 2771:hereditary 1787:Properties 867:closed map 494:continuous 288:it is the 95:Definition 2978:(1995) , 2707:∈ 2695:∩ 2549:τ 2546:∈ 2540:∖ 2414:τ 2411:∈ 2127:→ 2095:→ 2040:→ 1930:∘ 1900:→ 1848:→ 1469:{0}). If 1467:singleton 1341:, is the 1245:τ 1242:∈ 1216:τ 1178:τ 1105:τ 1067:τ 934:τ 853:ι 785:ι 734:ι 616:− 612:ι 591:ι 521:injection 507:ι 474:↪ 465:ι 389:τ 333:τ 243:τ 240:∈ 234:∣ 228:∩ 210:τ 116:τ 87:, or the 83:, or the 3038:Topology 2841:See also 2809:Being a 2802:Being a 2489:Suppose 2360:Suppose 1831:and let 1281:Examples 799:open map 702:is then 662:open in 370:subspace 314:open set 312:with an 79:(or the 69:topology 47:subspace 39:topology 3008:0507446 2912:2456045 1756:, 1)). 1751:⁄ 1693:⁄ 1683:⁄ 1669:⁄ 1659:⁄ 1623:⁄ 969:" and " 447:as the 3021:  3006:  2996:  2940:  2910:  2900:  2822:Being 2754:metric 1883:a map 1674:) and 917:, and 797:is an 519:is an 174:, the 133:subset 131:and a 58:subset 2986:Dover 2864:Notes 2668:then 2646:basis 2644:is a 2257:then 1505:< 1501:< 1497:with 865:is a 348:. If 56:is a 49:of a 3019:ISBN 2994:ISBN 2938:ISBN 2898:ISBN 2832:and 2648:for 2529:(so 2400:(so 1592:Let 1583:open 1489:and 1473:and 1465:the 1463:only 1348:The 1088:and 1009:and 642:for 45:, a 2930:doi 2890:doi 2624:If 2217:If 2078:If 2023:If 492:is 427:of 372:of 316:in 292:of 178:on 154:of 91:). 63:of 37:In 3034:: 3004:MR 3002:, 2992:, 2974:; 2963:, 2936:, 2908:MR 2906:, 2896:, 2872:^ 2777:. 2019:. 1976:. 1664:, 1481:, 869:. 750:. 682:. 496:. 2984:( 2932:: 2892:: 2745:. 2733:S 2713:} 2710:B 2704:U 2701:: 2698:S 2692:U 2689:{ 2686:= 2681:S 2677:B 2656:X 2632:B 2621:. 2609:X 2589:S 2569:S 2543:S 2537:X 2517:X 2497:S 2486:. 2474:X 2454:S 2434:S 2408:S 2388:X 2368:S 2357:. 2345:X 2325:S 2305:A 2285:X 2265:A 2245:S 2225:A 2214:. 2202:X 2182:S 2162:S 2139:) 2136:X 2133:( 2130:f 2124:X 2121:: 2118:f 2098:Y 2092:X 2089:: 2086:f 2063:S 2043:Y 2037:X 2034:: 2031:f 2007:X 1987:S 1964:Y 1933:f 1927:i 1903:Y 1897:Z 1894:: 1891:f 1871:Z 1851:X 1845:Y 1842:: 1839:i 1819:X 1799:Y 1782:. 1769:R 1758:S 1753:2 1749:1 1733:R 1711:R 1700:S 1695:2 1691:1 1685:2 1681:1 1676:S 1671:2 1667:1 1661:2 1657:1 1641:R 1630:S 1625:2 1621:1 1605:R 1594:S 1589:. 1568:R 1543:R 1521:R 1507:b 1503:x 1499:a 1495:x 1491:b 1487:a 1483:b 1479:a 1475:b 1471:a 1448:Q 1426:R 1404:Q 1382:R 1360:Q 1345:. 1328:R 1294:R 1265:S 1239:S 1219:) 1213:, 1210:X 1207:( 1187:) 1182:S 1174:, 1171:S 1168:( 1148:X 1128:S 1108:) 1102:, 1099:X 1096:( 1076:) 1071:S 1063:, 1060:S 1057:( 1037:X 1017:X 997:S 977:X 957:S 937:) 931:, 928:X 925:( 905:X 885:S 829:X 809:S 761:S 714:X 690:S 670:X 650:U 630:) 627:U 624:( 619:1 571:S 551:X 531:S 477:X 471:S 468:: 435:X 415:S 392:) 386:, 383:X 380:( 356:S 336:) 330:, 327:X 324:( 300:S 272:S 249:. 246:} 237:U 231:U 225:S 222:{ 219:= 214:S 186:S 162:X 142:S 119:) 113:, 110:X 107:( 73:X 65:X 61:S 54:X 34:. 20:)

Index

Subspace (topology)
Initial topology
topology
mathematics
topological space
subset
topology
subset
if and only if
intersection
open set
coarsest topology
inclusion map
continuous
injection
homeomorphic
topological embedding
open map
closed map
real numbers
natural numbers
discrete topology
rational numbers
singleton
disconnected space
if and only if
Characteristic property of the subspace topology
basis
metric space
metric

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