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Meagre set

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is nonmeager, no set is at the same time meagre and comeager, every comeagre set is nonmeagre, and there can be nonmeagre sets that are not comeagre, that is, with nonmeagre complement. See the Examples section below.
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from reals to reals where the image of a null set of reals is a meagre set, and vice versa. In fact, the image of a set of reals under the map is null if and only if the original set was meagre, and vice versa.
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Just as a nowhere dense subset need not be closed, but is always contained in a closed nowhere dense subset (viz, its closure), a meagre set need not be an
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is comeagre and nonmeagre. In particular that set is not empty. This is one way to show the existence of continuous nowhere differentiable functions.
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some authors may use the phrase "meagre/nonmeagre subspace" to mean a vector subspace that is a meagre/nonmeagre set relative to the whole space.
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will be a set that is nonmeagre in itself, which is not the same as being nonmeagre in the whole space. Be aware however that in the context of
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All subsets and all countable unions of meagre sets are meagre. Thus the meagre subsets of a fixed space form a
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is nonmeagre (because no set containing the isolated point can be nowhere dense). In particular, every nonempty
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and all countable intersections of comeagre sets are comeagre. Every superset of a nonmeagre set is nonmeagre.
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The empty set is always a closed nowhere dense (and thus meagre) subset of every topological space.
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Dually, there can be nonmeagre sets with measure zero. The complement of any meagre set of measure
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is meagre, whereas any topological space that contains an isolated point is nonmeagre. Because the
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is meagre, every subset is both meagre and comeagre, and there are no nonmeagre sets. If the space
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that splits every nonempty open set into two nonmeagre sets. That is, for every nonempty open set
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are countable, they are meagre as a subset of the reals and as a space—that is, they do not form a
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https://mathoverflow.net/questions/3188/are-proper-linear-subspaces-of-banach-spaces-always-meager
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is meagre. Consequently, any closed subset with empty interior is meagre. Thus a closed subset of
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https://www.ams.org/journals/bull/1966-72-04/S0002-9904-1966-11547-1/S0002-9904-1966-11547-1.pdf
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Any subset of a meagre set is a meagre set, as is the union of countably many meagre sets. If
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is meagre. So it is also meagre in any space that contains it as a subspace. For example,
4830: 4829:, i.e. sets of Lebesgue measure 0. The Erdos–Sierpinski duality theorem states that if the 3699:, are closed nowhere dense and they can be constructed with a measure arbitrarily close to 3573: 1090: 2131: 8: 4428:
that have nonempty interiors such that every nonempty open set has a subset belonging to
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Dually, just as the complement of a nowhere dense set need not be open, but has a dense
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There exist nowhere dense subsets (which are thus meagre subsets) that have positive
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the union of any family of open sets of the first category is of the first category.
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is equivalent to being meagre in itself, and similarly for the nonmeagre property.
1625: 858: 24: 1520:{\displaystyle S=(\mathbb {Q} \times \mathbb {Q} )\cup (\mathbb {R} \times \{0\})} 1387:. It is nonmeagre in itself (since as a subspace it contains an isolated point). 600:. (This use of the prefix "co" is consistent with its use in other terms such as " 5319: 4847: 2056: 2053: 4859: 3692: 3403:(because otherwise it would be nowhere dense and thus of the first category). 3317: 3284:
is nonmeagre if and only if every countable intersection of dense open sets in
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Every nowhere dense subset is a meagre set. Consequently, any closed subset of
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is nonmeagre but there exist nonmeagre spaces that are not Baire spaces. Since
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The notions of nonmeagre and comeagre should not be confused. If the space
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Quintanilla, M. (2022). "The real numbers in inner models of set theory".
4963:"Following Bourbaki , a topological space is called a Baire space if ..." 4862: – Mathematical set regarded as insignificant, for analogs to meagre 2278: 2039: 2020: 1629: 1620:
is not a meagre topological space). A countable Hausdorff space without
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Meagre sets have a useful alternative characterization in terms of the
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Meagre sets play an important role in the formulation of the notion of
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in a precise sense detailed below. A set that is not meagre is called
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set made from nowhere dense sets (by taking the closure of each set).
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The union of a countable number of such sets with measure approaching
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zero, and can even have full measure. For example, in the interval
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But it is a nonmeagre subspace, that is, it is nonmeagre in itself.
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is a complete metric space, it is nonmeagre. So the complement of
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of subsets; that is, any subset of a meagre set is meagre, and the
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is nonmeagre in itself. And for an open set or a dense set in
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wins if the intersection of this sequence contains a point in
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is nonmeagre. But it is not comeagre, as its complement
5267:(Second ed.). New York: Springer. pp. 62–65. 1900:
that have a derivative at some point is meagre. Since
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alternately choose successively smaller elements of
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is a sequence that enumerates the rational numbers.
5077: 702:As an additional point of terminology, if a subset 179:. See the corresponding article for more details. 4808: 4784: 4764: 4730: 4710: 4690: 4670: 4608: 4584: 4561: 4541: 4490: 4467: 4447: 4420: 4400: 4376: 4344: 4311: 4276: 4247: 4211: 4165: 4001: 3981: 3956: 3924: 3892: 3857: 3837: 3805: 3783: 3763: 3731: 3711: 3684: 3648: 3612: 3589: 3562: 3510: 3490: 3444: 3424: 3395: 3375: 3355: 3335: 3296: 3276: 3253: 3233: 3210: 3190: 3170: 3147: 3124: 3101: 3081: 3061: 3041: 3018: 2996: 2973: 2953: 2933: 2913: 2890: 2868: 2845: 2825: 2802: 2775: 2752: 2732: 2712: 2692: 2669: 2647: 2624: 2604: 2584: 2564: 2541: 2519: 2496: 2476: 2453: 2429: 2406: 2386: 2366: 2339: 2319: 2266: 2232: 2212: 2192: 2172: 2149: 2120: 2090: 2003:On an infinite-dimensional Banach, there exists a 1992: 1953: 1933: 1892: 1860: 1836: 1804: 1760: 1734: 1708: 1680: 1658: 1612: 1586: 1552: 1519: 1448: 1416: 1379: 1357: 1335: 1270: 1245: 1217: 1192: 1170: 1148: 1111: 1079: 1047: 1006: 974: 934: 822: 802: 778: 758: 734: 714: 690: 670: 643: 616: 592: 572: 542: 511: 481: 461: 419: 398: 367: 336: 307: 282: 254: 223: 194: 163: 143: 124:The definition of meagre set uses the notion of a 109: 5193: 5138:"Is there a measure zero set which isn't meagre?" 5052: 5000: 4888: 4868: – Difference of an open set by a meager set 5356: 4825:Many arguments about meagre sets also apply to 1961:, which consists of the continuous real-valued 5194:Narici, Lawrence; Beckenstein, Edward (2011). 4222: 3967:Here is another example of a nonmeagre set in 1336:{\displaystyle (\cap \mathbb {Q} )\cup \{2\}} 1278:But it is nonmeagre in itself, since it is a 1581: 1575: 1511: 1505: 1411: 1405: 1330: 1324: 628:of sets, each of whose interior is dense in 5154: 4820: 2015:Characterizations and sufficient conditions 62:The meagre subsets of a fixed space form a 5012: 935:{\displaystyle X=\cup (\cap \mathbb {Q} )} 624:if and only if it is equal to a countable 5160: 5031: 3975: 3642: 1702: 1674: 1606: 1568: 1540: 1498: 1484: 1476: 1433: 1398: 1373: 1351: 1314: 1261: 1239: 1208: 1186: 1164: 1142: 968: 925: 5220: 4975: 4918:"Sur les fonctions de variables réelles" 4900: 4850: – Type of topological vector space 2786:And correspondingly for nonmeagre sets: 2320:{\displaystyle A\subseteq Y\subseteq X,} 1587:{\displaystyle \mathbb {R} \times \{0\}} 1417:{\displaystyle \mathbb {R} \times \{0\}} 5317: 5112: 5046: 4549:In the Banach–Mazur game, two players, 4542:{\displaystyle MZ(X,Y,{\mathcal {W}}).} 3314:locally convex topological vector space 2007:whose kernel is nonmeagre. Also, under 1868:of continuous real-valued functions on 1812:of continuous real-valued functions on 1709:{\displaystyle U\subseteq \mathbb {R} } 1635:Any topological space that contains an 5357: 5258: 5100: 4935: 3155:that is meagre in itself is meagre in 5281: 5124: 5088: 4915: 2200:is empty is of the first category of 2023:is nonmeagre. In particular, by the 16:"Small" subset of a topological space 5293:McGraw-Hill Science/Engineering/Math 5178:The Erdos-Sierpinski Duality Theorem 4938:"Cartesian products of Baire spaces" 4355: 2437:However the following results hold: 4772:meeting the above criteria, player 4212:{\displaystyle r_{1},r_{2},\ldots } 3623:Meagre subsets and Lebesgue measure 3491:{\displaystyle S_{1},S_{2},\ldots } 2220:(that is, it is a meager subset of 2063:, they are also nonmeagre spaces. 13: 5180:, notes. Accessed 18 January 2023. 4757: 4601: 4528: 4498:Then there is a Banach–Mazur game 4437: 4393: 4053: 4032: 3363:that is of the second category in 315:. Otherwise, the subset is called 14: 5381: 5226:General Topology 2: Chapters 5–10 4352:set formed from dense open sets. 2281:of subsets, a suitable notion of 1752: 1449:{\displaystyle \mathbb {R} ^{2}.} 975:{\displaystyle \cap \mathbb {Q} } 564: 3383:must have non-empty interior in 1963:nowhere differentiable functions 1553:{\displaystyle \mathbb {R} ^{2}} 5187: 5170: 5148: 5130: 5066: 4448:{\displaystyle {\mathcal {W}},} 3135:In particular, every subset of 2005:discontinuous linear functional 849:were the original ones used by 5006: 4929: 4909: 4894: 4765:{\displaystyle {\mathcal {W}}} 4609:{\displaystyle {\mathcal {W}}} 4533: 4511: 4401:{\displaystyle {\mathcal {W}}} 3951: 3939: 3919: 3907: 3884: 3872: 3832: 3820: 3758: 3746: 3679: 3667: 3323:Every nowhere dense subset of 2144: 2138: 2082: 1984: 1972: 1928: 1925: 1913: 1910: 1887: 1875: 1831: 1819: 1799: 1796: 1784: 1781: 1560:even though its meagre subset 1514: 1494: 1488: 1472: 1318: 1307: 1295: 1292: 1106: 1094: 1074: 1062: 1042: 1030: 1001: 989: 961: 949: 929: 918: 906: 903: 897: 885: 857:terminology was introduced by 430:A topological space is called 291:if it is a countable union of 92: 1: 5261:"The Banach Category Theorem" 5001:Narici & Beckenstein 2011 4889:Narici & Beckenstein 2011 3597:is of the second category in 3432:is of the second category in 3307: 1271:{\displaystyle \mathbb {R} .} 1218:{\displaystyle \mathbb {R} .} 1156:is both a meagre subspace of 4901:Schaefer, Helmut H. (1966). 4325:sets), but contains a dense 3982:{\displaystyle \mathbb {R} } 3649:{\displaystyle \mathbb {R} } 3425:{\displaystyle B\subseteq X} 2121:{\displaystyle S\subseteq X} 1761:{\displaystyle U\setminus H} 1681:{\displaystyle \mathbb {R} } 1613:{\displaystyle \mathbb {R} } 1380:{\displaystyle \mathbb {R} } 1358:{\displaystyle \mathbb {R} } 1246:{\displaystyle \mathbb {R} } 1193:{\displaystyle \mathbb {R} } 1171:{\displaystyle \mathbb {R} } 1149:{\displaystyle \mathbb {Q} } 853:in his thesis of 1899. The 604:".) A subset is comeagre in 573:{\displaystyle X\setminus A} 74:many meagre sets is meagre. 7: 4922:Annali di Mat. Pura ed Appl 4903:"Topological Vector Spaces" 4841: 4345:{\displaystyle G_{\delta }} 4321:(countable intersection of 4312:{\displaystyle G_{\delta }} 4277:{\displaystyle F_{\sigma }} 4248:{\displaystyle F_{\sigma }} 4223:Relation to Borel hierarchy 1014:is nonmeagre and comeagre. 864: 10: 5386: 5318:Willard, Stephen (2004) . 4408:be a family of subsets of 5196:Topological Vector Spaces 3739:gives a meagre subset of 3697:Smith–Volterra–Cantor set 2251:states that in any space 2128:is meagre if and only if 2033:locally compact Hausdorff 1200:) and a meagre subset of 836:topological vector spaces 5259:Oxtoby, John C. (1980). 5234:Éléments de mathématique 4872: 4821:Erdos–Sierpinski duality 4384:be a topological space, 2414:without being meagre in 2091:{\displaystyle h:X\to X} 1343:is not nowhere dense in 4959:10.4064/fm-49-2-157-166 4946:Fundamenta Mathematicae 3900:and hence nonmeagre in 2247:Banach category theorem 1735:{\displaystyle U\cap H} 1424:is meagre in the plane 1017:In the nonmeagre space 872:In the nonmeagre space 722:of a topological space 5370:Descriptive set theory 5033:10.4064/sm-3-1-174-179 4810: 4786: 4766: 4732: 4712: 4692: 4672: 4616:to produce a sequence 4610: 4586: 4563: 4543: 4492: 4469: 4449: 4422: 4402: 4378: 4346: 4313: 4278: 4249: 4213: 4167: 4057: 4036: 4003: 3983: 3958: 3926: 3894: 3859: 3839: 3807: 3785: 3765: 3733: 3713: 3686: 3650: 3614: 3591: 3564: 3512: 3492: 3446: 3426: 3397: 3377: 3357: 3337: 3298: 3278: 3255: 3235: 3212: 3192: 3172: 3149: 3126: 3103: 3083: 3063: 3043: 3020: 2998: 2975: 2955: 2935: 2915: 2892: 2870: 2847: 2827: 2804: 2777: 2754: 2734: 2714: 2694: 2671: 2649: 2626: 2606: 2586: 2566: 2543: 2521: 2498: 2478: 2455: 2431: 2408: 2388: 2368: 2341: 2321: 2268: 2234: 2214: 2194: 2174: 2151: 2122: 2092: 2025:Baire category theorem 1994: 1955: 1935: 1894: 1862: 1838: 1806: 1762: 1736: 1710: 1682: 1660: 1614: 1588: 1554: 1521: 1450: 1418: 1381: 1365:, but it is meagre in 1359: 1337: 1272: 1247: 1219: 1194: 1172: 1150: 1113: 1081: 1049: 1008: 976: 936: 824: 804: 780: 760: 736: 716: 692: 672: 654:Remarks on terminology 645: 618: 594: 574: 544: 513: 483: 463: 421: 400: 369: 338: 309: 284: 256: 225: 196: 165: 145: 111: 83:Baire category theorem 57:of the second category 4811: 4787: 4767: 4733: 4713: 4693: 4673: 4611: 4587: 4564: 4544: 4493: 4470: 4450: 4423: 4403: 4379: 4347: 4314: 4279: 4250: 4214: 4168: 4037: 4016: 4004: 3984: 3959: 3927: 3895: 3860: 3840: 3808: 3786: 3766: 3734: 3714: 3687: 3651: 3615: 3592: 3590:{\displaystyle S_{n}} 3565: 3513: 3493: 3447: 3427: 3398: 3378: 3358: 3338: 3299: 3279: 3256: 3236: 3213: 3198:that is nonmeagre in 3193: 3173: 3150: 3127: 3104: 3084: 3064: 3044: 3021: 2999: 2976: 2956: 2936: 2916: 2893: 2871: 2848: 2828: 2805: 2778: 2755: 2735: 2715: 2695: 2672: 2650: 2627: 2607: 2587: 2567: 2544: 2522: 2499: 2479: 2456: 2432: 2409: 2389: 2369: 2342: 2322: 2269: 2235: 2215: 2195: 2175: 2152: 2123: 2093: 2029:complete metric space 1995: 1956: 1936: 1895: 1863: 1844:with the topology of 1839: 1807: 1763: 1737: 1711: 1683: 1661: 1615: 1589: 1555: 1522: 1451: 1419: 1382: 1360: 1338: 1280:complete metric space 1273: 1248: 1220: 1195: 1173: 1151: 1114: 1112:{\displaystyle (1,2]} 1082: 1050: 1009: 977: 937: 825: 805: 786:can also be called a 781: 761: 737: 717: 693: 673: 646: 619: 595: 575: 545: 514: 484: 464: 422: 401: 370: 339: 310: 285: 257: 226: 197: 166: 151:that is, a subset of 146: 112: 37:set of first category 5265:Measure and Category 4916:Baire, René (1899). 4831:continuum hypothesis 4800: 4776: 4752: 4722: 4718:; otherwise, player 4702: 4682: 4620: 4596: 4573: 4553: 4502: 4479: 4459: 4432: 4412: 4388: 4368: 4329: 4296: 4261: 4232: 4177: 4013: 3993: 3971: 3936: 3904: 3869: 3849: 3817: 3797: 3775: 3743: 3723: 3703: 3664: 3638: 3601: 3574: 3522: 3502: 3456: 3436: 3410: 3387: 3367: 3347: 3327: 3288: 3268: 3264:A topological space 3245: 3222: 3202: 3182: 3159: 3139: 3113: 3093: 3073: 3053: 3030: 3010: 2985: 2965: 2945: 2925: 2902: 2882: 2857: 2837: 2814: 2794: 2764: 2744: 2724: 2704: 2681: 2661: 2636: 2616: 2596: 2576: 2553: 2533: 2508: 2488: 2465: 2445: 2418: 2398: 2378: 2355: 2331: 2296: 2255: 2224: 2204: 2184: 2164: 2150:{\displaystyle h(S)} 2132: 2106: 2070: 2035:space is nonmeagre. 1969: 1945: 1904: 1872: 1852: 1816: 1775: 1768:are both nonmeagre. 1746: 1720: 1692: 1670: 1666:of the real numbers 1650: 1602: 1564: 1535: 1463: 1428: 1394: 1369: 1347: 1289: 1257: 1253:and hence meagre in 1235: 1231:is nowhere dense in 1204: 1182: 1160: 1138: 1091: 1059: 1021: 986: 982:is meagre. The set 946: 876: 814: 794: 770: 750: 726: 706: 682: 662: 632: 608: 584: 558: 531: 500: 473: 453: 411: 387: 356: 325: 299: 274: 243: 212: 186: 155: 132: 101: 5288:Functional Analysis 5013:Banach, S. (1931). 5003:, pp. 371–423. 4936:Oxtoby, J. (1961). 4833:holds, there is an 4746: —  3964:is a Baire space. 3865:and is comeagre in 2031:and every nonempty 1934:{\displaystyle C()} 1846:uniform convergence 1805:{\displaystyle C()} 1119:is also nonmeagre. 87:functional analysis 5330:Dover Publications 5230:Topologie Générale 4806: 4782: 4762: 4744: 4728: 4708: 4688: 4668: 4606: 4585:{\displaystyle Q,} 4582: 4559: 4539: 4491:{\displaystyle Y.} 4488: 4465: 4445: 4418: 4398: 4374: 4342: 4309: 4274: 4245: 4209: 4163: 4140: 4091: 3999: 3979: 3954: 3922: 3890: 3855: 3835: 3803: 3784:{\displaystyle 1.} 3781: 3761: 3729: 3712:{\displaystyle 1.} 3709: 3682: 3646: 3613:{\displaystyle X.} 3610: 3587: 3570:then at least one 3560: 3508: 3488: 3442: 3422: 3393: 3373: 3353: 3333: 3294: 3274: 3251: 3234:{\displaystyle X,} 3231: 3208: 3188: 3171:{\displaystyle X.} 3168: 3145: 3125:{\displaystyle X.} 3122: 3099: 3079: 3059: 3042:{\displaystyle X,} 3039: 3016: 2997:{\displaystyle X.} 2994: 2971: 2951: 2931: 2914:{\displaystyle X,} 2911: 2888: 2869:{\displaystyle Y.} 2866: 2843: 2826:{\displaystyle X,} 2823: 2800: 2776:{\displaystyle X.} 2773: 2750: 2730: 2710: 2693:{\displaystyle X,} 2690: 2667: 2648:{\displaystyle X.} 2645: 2622: 2602: 2582: 2565:{\displaystyle X,} 2562: 2539: 2520:{\displaystyle X.} 2517: 2494: 2477:{\displaystyle Y,} 2474: 2451: 2430:{\displaystyle Y.} 2427: 2404: 2384: 2367:{\displaystyle X.} 2364: 2337: 2317: 2267:{\displaystyle X,} 2264: 2230: 2210: 2190: 2180:whose interior in 2170: 2147: 2118: 2088: 1990: 1951: 1931: 1890: 1858: 1834: 1802: 1758: 1732: 1706: 1678: 1656: 1646:There is a subset 1610: 1594:is a nonmeagre sub 1584: 1550: 1517: 1446: 1414: 1377: 1355: 1333: 1268: 1243: 1215: 1190: 1168: 1146: 1109: 1077: 1048:{\displaystyle X=} 1045: 1004: 972: 932: 832:nonmeagre subspace 820: 800: 776: 756: 732: 712: 688: 668: 644:{\displaystyle X.} 641: 614: 590: 570: 543:{\displaystyle X,} 540: 512:{\displaystyle X,} 509: 479: 459: 417: 407:The qualifier "in 399:{\displaystyle X.} 396: 368:{\displaystyle X,} 365: 337:{\displaystyle X,} 334: 305: 280: 255:{\displaystyle X,} 252: 224:{\displaystyle X,} 221: 192: 161: 144:{\displaystyle X,} 141: 107: 5339:978-0-486-43479-7 5302:978-0-07-054236-5 5243:978-3-540-64563-4 5222:Bourbaki, Nicolas 5127:, pp. 42–43. 4866:Property of Baire 4809:{\displaystyle X} 4785:{\displaystyle Q} 4742: 4731:{\displaystyle Q} 4711:{\displaystyle X} 4691:{\displaystyle P} 4562:{\displaystyle P} 4475:be any subset of 4468:{\displaystyle X} 4421:{\displaystyle Y} 4377:{\displaystyle Y} 4362:Banach–Mazur game 4356:Banach–Mazur game 4139: 4090: 4002:{\displaystyle 0} 3893:{\displaystyle ,} 3858:{\displaystyle 0} 3806:{\displaystyle 1} 3732:{\displaystyle 1} 3511:{\displaystyle X} 3445:{\displaystyle X} 3396:{\displaystyle X} 3376:{\displaystyle X} 3356:{\displaystyle X} 3336:{\displaystyle X} 3297:{\displaystyle X} 3277:{\displaystyle X} 3254:{\displaystyle X} 3211:{\displaystyle X} 3191:{\displaystyle X} 3148:{\displaystyle X} 3102:{\displaystyle A} 3082:{\displaystyle Y} 3062:{\displaystyle A} 3019:{\displaystyle Y} 2974:{\displaystyle A} 2954:{\displaystyle Y} 2934:{\displaystyle A} 2891:{\displaystyle Y} 2846:{\displaystyle A} 2803:{\displaystyle A} 2753:{\displaystyle A} 2733:{\displaystyle Y} 2713:{\displaystyle A} 2670:{\displaystyle Y} 2625:{\displaystyle A} 2605:{\displaystyle Y} 2585:{\displaystyle A} 2542:{\displaystyle Y} 2497:{\displaystyle A} 2454:{\displaystyle A} 2407:{\displaystyle X} 2394:may be meagre in 2387:{\displaystyle A} 2349:subspace topology 2340:{\displaystyle Y} 2233:{\displaystyle X} 2213:{\displaystyle X} 2193:{\displaystyle X} 2173:{\displaystyle X} 1993:{\displaystyle ,} 1954:{\displaystyle A} 1861:{\displaystyle A} 1659:{\displaystyle H} 823:{\displaystyle X} 803:{\displaystyle X} 779:{\displaystyle A} 759:{\displaystyle X} 744:subspace topology 735:{\displaystyle X} 715:{\displaystyle A} 691:{\displaystyle X} 671:{\displaystyle X} 617:{\displaystyle X} 593:{\displaystyle X} 482:{\displaystyle X} 462:{\displaystyle A} 420:{\displaystyle X} 308:{\displaystyle X} 283:{\displaystyle X} 195:{\displaystyle X} 164:{\displaystyle X} 119:topological space 110:{\displaystyle X} 47:that is small or 45:topological space 5377: 5365:General topology 5351: 5321:General Topology 5314: 5278: 5255: 5217: 5181: 5174: 5168: 5166: 5164: 5152: 5146: 5145: 5134: 5128: 5122: 5116: 5110: 5104: 5098: 5092: 5086: 5075: 5070: 5064: 5059: 5050: 5044: 5038: 5037: 5035: 5010: 5004: 4998: 4979: 4973: 4964: 4962: 4942: 4933: 4927: 4925: 4913: 4907: 4906: 4898: 4892: 4886: 4854:Generic property 4815: 4813: 4812: 4807: 4794:winning strategy 4791: 4789: 4788: 4783: 4771: 4769: 4768: 4763: 4761: 4760: 4747: 4737: 4735: 4734: 4729: 4717: 4715: 4714: 4709: 4697: 4695: 4694: 4689: 4677: 4675: 4674: 4669: 4658: 4657: 4645: 4644: 4632: 4631: 4615: 4613: 4612: 4607: 4605: 4604: 4591: 4589: 4588: 4583: 4568: 4566: 4565: 4560: 4548: 4546: 4545: 4540: 4532: 4531: 4497: 4495: 4494: 4489: 4474: 4472: 4471: 4466: 4454: 4452: 4451: 4446: 4441: 4440: 4427: 4425: 4424: 4419: 4407: 4405: 4404: 4399: 4397: 4396: 4383: 4381: 4380: 4375: 4351: 4349: 4348: 4343: 4341: 4340: 4318: 4316: 4315: 4310: 4308: 4307: 4283: 4281: 4280: 4275: 4273: 4272: 4254: 4252: 4251: 4246: 4244: 4243: 4218: 4216: 4215: 4210: 4202: 4201: 4189: 4188: 4172: 4170: 4169: 4164: 4162: 4158: 4157: 4156: 4145: 4141: 4132: 4121: 4120: 4108: 4107: 4096: 4092: 4083: 4072: 4071: 4056: 4051: 4035: 4030: 4008: 4006: 4005: 4000: 3988: 3986: 3985: 3980: 3978: 3963: 3961: 3960: 3957:{\displaystyle } 3955: 3931: 3929: 3928: 3925:{\displaystyle } 3923: 3899: 3897: 3896: 3891: 3864: 3862: 3861: 3856: 3844: 3842: 3841: 3838:{\displaystyle } 3836: 3812: 3810: 3809: 3804: 3790: 3788: 3787: 3782: 3770: 3768: 3767: 3764:{\displaystyle } 3762: 3738: 3736: 3735: 3730: 3718: 3716: 3715: 3710: 3691: 3689: 3688: 3685:{\displaystyle } 3683: 3658:Lebesgue measure 3655: 3653: 3652: 3647: 3645: 3634:A meagre set in 3629:Lebesgue measure 3619: 3617: 3616: 3611: 3596: 3594: 3593: 3588: 3586: 3585: 3569: 3567: 3566: 3561: 3553: 3552: 3540: 3539: 3517: 3515: 3514: 3509: 3497: 3495: 3494: 3489: 3481: 3480: 3468: 3467: 3451: 3449: 3448: 3443: 3431: 3429: 3428: 3423: 3402: 3400: 3399: 3394: 3382: 3380: 3379: 3374: 3362: 3360: 3359: 3354: 3342: 3340: 3339: 3334: 3303: 3301: 3300: 3295: 3283: 3281: 3280: 3275: 3260: 3258: 3257: 3252: 3241:being meagre in 3240: 3238: 3237: 3232: 3217: 3215: 3214: 3209: 3197: 3195: 3194: 3189: 3178:Every subset of 3177: 3175: 3174: 3169: 3154: 3152: 3151: 3146: 3131: 3129: 3128: 3123: 3109:is nonmeagre in 3108: 3106: 3105: 3100: 3088: 3086: 3085: 3080: 3069:is nonmeagre in 3068: 3066: 3065: 3060: 3048: 3046: 3045: 3040: 3025: 3023: 3022: 3017: 3003: 3001: 3000: 2995: 2981:is nonmeagre in 2980: 2978: 2977: 2972: 2960: 2958: 2957: 2952: 2941:is nonmeagre in 2940: 2938: 2937: 2932: 2920: 2918: 2917: 2912: 2897: 2895: 2894: 2889: 2875: 2873: 2872: 2867: 2853:is nonmeagre in 2852: 2850: 2849: 2844: 2832: 2830: 2829: 2824: 2810:is nonmeagre in 2809: 2807: 2806: 2801: 2782: 2780: 2779: 2774: 2759: 2757: 2756: 2751: 2739: 2737: 2736: 2731: 2719: 2717: 2716: 2711: 2699: 2697: 2696: 2691: 2676: 2674: 2673: 2668: 2654: 2652: 2651: 2646: 2631: 2629: 2628: 2623: 2611: 2609: 2608: 2603: 2591: 2589: 2588: 2583: 2571: 2569: 2568: 2563: 2548: 2546: 2545: 2540: 2526: 2524: 2523: 2518: 2503: 2501: 2500: 2495: 2483: 2481: 2480: 2475: 2460: 2458: 2457: 2452: 2436: 2434: 2433: 2428: 2413: 2411: 2410: 2405: 2393: 2391: 2390: 2385: 2373: 2371: 2370: 2365: 2346: 2344: 2343: 2338: 2326: 2324: 2323: 2318: 2285:. Dually, all 2273: 2271: 2270: 2265: 2250: 2249: 2239: 2237: 2236: 2231: 2219: 2217: 2216: 2211: 2199: 2197: 2196: 2191: 2179: 2177: 2176: 2171: 2156: 2154: 2153: 2148: 2127: 2125: 2124: 2119: 2097: 2095: 2094: 2089: 2061:are Baire spaces 1999: 1997: 1996: 1991: 1960: 1958: 1957: 1952: 1940: 1938: 1937: 1932: 1899: 1897: 1896: 1893:{\displaystyle } 1891: 1867: 1865: 1864: 1859: 1843: 1841: 1840: 1837:{\displaystyle } 1835: 1811: 1809: 1808: 1803: 1767: 1765: 1764: 1759: 1741: 1739: 1738: 1733: 1715: 1713: 1712: 1707: 1705: 1687: 1685: 1684: 1679: 1677: 1665: 1663: 1662: 1657: 1626:rational numbers 1619: 1617: 1616: 1611: 1609: 1593: 1591: 1590: 1585: 1571: 1559: 1557: 1556: 1551: 1549: 1548: 1543: 1526: 1524: 1523: 1518: 1501: 1487: 1479: 1455: 1453: 1452: 1447: 1442: 1441: 1436: 1423: 1421: 1420: 1415: 1401: 1386: 1384: 1383: 1378: 1376: 1364: 1362: 1361: 1356: 1354: 1342: 1340: 1339: 1334: 1317: 1277: 1275: 1274: 1269: 1264: 1252: 1250: 1249: 1244: 1242: 1224: 1222: 1221: 1216: 1211: 1199: 1197: 1196: 1191: 1189: 1177: 1175: 1174: 1169: 1167: 1155: 1153: 1152: 1147: 1145: 1118: 1116: 1115: 1110: 1086: 1084: 1083: 1080:{\displaystyle } 1078: 1054: 1052: 1051: 1046: 1013: 1011: 1010: 1007:{\displaystyle } 1005: 981: 979: 978: 973: 971: 941: 939: 938: 933: 928: 829: 827: 826: 821: 809: 807: 806: 801: 785: 783: 782: 777: 765: 763: 762: 757: 741: 739: 738: 733: 721: 719: 718: 713: 697: 695: 694: 689: 677: 675: 674: 669: 650: 648: 647: 642: 623: 621: 620: 615: 599: 597: 596: 591: 579: 577: 576: 571: 549: 547: 546: 541: 526: 525: 518: 516: 515: 510: 495: 494: 488: 486: 485: 480: 468: 466: 465: 460: 444: 443: 436: 435: 426: 424: 423: 418: 405: 403: 402: 397: 382: 381: 374: 372: 371: 366: 351: 350: 349:nonmeagre subset 343: 341: 340: 335: 321: 320: 314: 312: 311: 306: 289: 287: 286: 281: 269: 268: 261: 259: 258: 253: 238: 237: 230: 228: 227: 222: 208: 207: 201: 199: 198: 193: 170: 168: 167: 162: 150: 148: 147: 142: 116: 114: 113: 108: 25:general topology 5385: 5384: 5380: 5379: 5378: 5376: 5375: 5374: 5355: 5354: 5340: 5303: 5275: 5244: 5206: 5190: 5185: 5184: 5175: 5171: 5153: 5149: 5136: 5135: 5131: 5123: 5119: 5115:, Theorem 25.2. 5111: 5107: 5099: 5095: 5087: 5078: 5071: 5067: 5060: 5053: 5049:, Theorem 25.5. 5045: 5041: 5011: 5007: 4999: 4982: 4974: 4967: 4940: 4934: 4930: 4914: 4910: 4899: 4895: 4887: 4880: 4875: 4848:Barrelled space 4844: 4823: 4818: 4801: 4798: 4797: 4796:if and only if 4777: 4774: 4773: 4756: 4755: 4753: 4750: 4749: 4745: 4723: 4720: 4719: 4703: 4700: 4699: 4683: 4680: 4679: 4653: 4649: 4640: 4636: 4627: 4623: 4621: 4618: 4617: 4600: 4599: 4597: 4594: 4593: 4574: 4571: 4570: 4554: 4551: 4550: 4527: 4526: 4503: 4500: 4499: 4480: 4477: 4476: 4460: 4457: 4456: 4436: 4435: 4433: 4430: 4429: 4413: 4410: 4409: 4392: 4391: 4389: 4386: 4385: 4369: 4366: 4365: 4358: 4336: 4332: 4330: 4327: 4326: 4303: 4299: 4297: 4294: 4293: 4268: 4264: 4262: 4259: 4258: 4239: 4235: 4233: 4230: 4229: 4225: 4197: 4193: 4184: 4180: 4178: 4175: 4174: 4146: 4130: 4126: 4125: 4116: 4112: 4097: 4081: 4077: 4076: 4067: 4063: 4062: 4058: 4052: 4041: 4031: 4020: 4014: 4011: 4010: 3994: 3991: 3990: 3974: 3972: 3969: 3968: 3937: 3934: 3933: 3905: 3902: 3901: 3870: 3867: 3866: 3850: 3847: 3846: 3818: 3815: 3814: 3798: 3795: 3794: 3776: 3773: 3772: 3744: 3741: 3740: 3724: 3721: 3720: 3704: 3701: 3700: 3693:fat Cantor sets 3665: 3662: 3661: 3641: 3639: 3636: 3635: 3625: 3602: 3599: 3598: 3581: 3577: 3575: 3572: 3571: 3548: 3544: 3535: 3531: 3523: 3520: 3519: 3503: 3500: 3499: 3498:are subsets of 3476: 3472: 3463: 3459: 3457: 3454: 3453: 3437: 3434: 3433: 3411: 3408: 3407: 3388: 3385: 3384: 3368: 3365: 3364: 3348: 3345: 3344: 3328: 3325: 3324: 3310: 3289: 3286: 3285: 3269: 3266: 3265: 3246: 3243: 3242: 3223: 3220: 3219: 3203: 3200: 3199: 3183: 3180: 3179: 3160: 3157: 3156: 3140: 3137: 3136: 3114: 3111: 3110: 3094: 3091: 3090: 3089:if and only if 3074: 3071: 3070: 3054: 3051: 3050: 3031: 3028: 3027: 3011: 3008: 3007: 2986: 2983: 2982: 2966: 2963: 2962: 2961:if and only if 2946: 2943: 2942: 2926: 2923: 2922: 2903: 2900: 2899: 2883: 2880: 2879: 2858: 2855: 2854: 2838: 2835: 2834: 2815: 2812: 2811: 2795: 2792: 2791: 2765: 2762: 2761: 2745: 2742: 2741: 2740:if and only if 2725: 2722: 2721: 2705: 2702: 2701: 2682: 2679: 2678: 2662: 2659: 2658: 2637: 2634: 2633: 2617: 2614: 2613: 2612:if and only if 2597: 2594: 2593: 2577: 2574: 2573: 2554: 2551: 2550: 2534: 2531: 2530: 2509: 2506: 2505: 2489: 2486: 2485: 2466: 2463: 2462: 2446: 2443: 2442: 2419: 2416: 2415: 2399: 2396: 2395: 2379: 2376: 2375: 2356: 2353: 2352: 2332: 2329: 2328: 2297: 2294: 2293: 2256: 2253: 2252: 2245: 2244: 2225: 2222: 2221: 2205: 2202: 2201: 2185: 2182: 2181: 2165: 2162: 2161: 2133: 2130: 2129: 2107: 2104: 2103: 2071: 2068: 2067: 2057:locally compact 2038:Every nonempty 2027:every nonempty 2019:Every nonempty 2017: 1970: 1967: 1966: 1946: 1943: 1942: 1905: 1902: 1901: 1873: 1870: 1869: 1853: 1850: 1849: 1817: 1814: 1813: 1776: 1773: 1772: 1747: 1744: 1743: 1721: 1718: 1717: 1701: 1693: 1690: 1689: 1673: 1671: 1668: 1667: 1651: 1648: 1647: 1622:isolated points 1605: 1603: 1600: 1599: 1567: 1565: 1562: 1561: 1544: 1539: 1538: 1536: 1533: 1532: 1527:is a meagre sub 1497: 1483: 1475: 1464: 1461: 1460: 1437: 1432: 1431: 1429: 1426: 1425: 1397: 1395: 1392: 1391: 1372: 1370: 1367: 1366: 1350: 1348: 1345: 1344: 1313: 1290: 1287: 1286: 1260: 1258: 1255: 1254: 1238: 1236: 1233: 1232: 1207: 1205: 1202: 1201: 1185: 1183: 1180: 1179: 1163: 1161: 1158: 1157: 1141: 1139: 1136: 1135: 1127: 1092: 1089: 1088: 1060: 1057: 1056: 1022: 1019: 1018: 987: 984: 983: 967: 947: 944: 943: 924: 877: 874: 873: 867: 847:second category 815: 812: 811: 795: 792: 791: 788:meagre subspace 771: 768: 767: 751: 748: 747: 727: 724: 723: 707: 704: 703: 683: 680: 679: 663: 660: 659: 633: 630: 629: 609: 606: 605: 585: 582: 581: 559: 556: 555: 532: 529: 528: 523: 522: 501: 498: 497: 492: 491: 474: 471: 470: 454: 451: 450: 441: 440: 438:(respectively, 433: 432: 412: 409: 408: 388: 385: 384: 380:second category 379: 378: 357: 354: 353: 348: 347: 326: 323: 322: 318: 317: 300: 297: 296: 275: 272: 271: 266: 265: 244: 241: 240: 235: 234: 213: 210: 209: 205: 204: 187: 184: 183: 156: 153: 152: 133: 130: 129: 102: 99: 98: 95: 31:(also called a 17: 12: 11: 5: 5383: 5373: 5372: 5367: 5353: 5352: 5338: 5315: 5301: 5279: 5273: 5256: 5242: 5218: 5205:978-1584888666 5204: 5189: 5186: 5183: 5182: 5169: 5147: 5129: 5117: 5105: 5093: 5076: 5065: 5051: 5039: 5026:(1): 174–179. 5005: 4980: 4978:, p. 192. 4965: 4953:(2): 157–166. 4928: 4908: 4893: 4891:, p. 389. 4877: 4876: 4874: 4871: 4870: 4869: 4863: 4860:Negligible set 4857: 4851: 4843: 4840: 4822: 4819: 4805: 4781: 4759: 4740: 4727: 4707: 4687: 4667: 4664: 4661: 4656: 4652: 4648: 4643: 4639: 4635: 4630: 4626: 4603: 4581: 4578: 4558: 4538: 4535: 4530: 4525: 4522: 4519: 4516: 4513: 4510: 4507: 4487: 4484: 4464: 4444: 4439: 4417: 4395: 4373: 4357: 4354: 4339: 4335: 4306: 4302: 4271: 4267: 4242: 4238: 4224: 4221: 4208: 4205: 4200: 4196: 4192: 4187: 4183: 4161: 4155: 4152: 4149: 4144: 4138: 4135: 4129: 4124: 4119: 4115: 4111: 4106: 4103: 4100: 4095: 4089: 4086: 4080: 4075: 4070: 4066: 4061: 4055: 4050: 4047: 4044: 4040: 4034: 4029: 4026: 4023: 4019: 3998: 3977: 3953: 3950: 3947: 3944: 3941: 3921: 3918: 3915: 3912: 3909: 3889: 3886: 3883: 3880: 3877: 3874: 3854: 3834: 3831: 3828: 3825: 3822: 3802: 3780: 3760: 3757: 3754: 3751: 3748: 3728: 3708: 3681: 3678: 3675: 3672: 3669: 3656:need not have 3644: 3624: 3621: 3609: 3606: 3584: 3580: 3559: 3556: 3551: 3547: 3543: 3538: 3534: 3530: 3527: 3507: 3487: 3484: 3479: 3475: 3471: 3466: 3462: 3441: 3421: 3418: 3415: 3392: 3372: 3352: 3332: 3318:barreled space 3309: 3306: 3293: 3273: 3250: 3230: 3227: 3207: 3187: 3167: 3164: 3144: 3133: 3132: 3121: 3118: 3098: 3078: 3058: 3038: 3035: 3015: 3004: 2993: 2990: 2970: 2950: 2930: 2910: 2907: 2887: 2876: 2865: 2862: 2842: 2822: 2819: 2799: 2784: 2783: 2772: 2769: 2749: 2729: 2709: 2689: 2686: 2666: 2655: 2644: 2641: 2621: 2601: 2581: 2561: 2558: 2538: 2527: 2516: 2513: 2493: 2473: 2470: 2450: 2426: 2423: 2403: 2383: 2363: 2360: 2336: 2316: 2313: 2310: 2307: 2304: 2301: 2283:negligible set 2263: 2260: 2229: 2209: 2189: 2169: 2146: 2143: 2140: 2137: 2117: 2114: 2111: 2102:then a subset 2087: 2084: 2081: 2078: 2075: 2016: 2013: 2009:Martin's axiom 1989: 1986: 1983: 1980: 1977: 1974: 1950: 1930: 1927: 1924: 1921: 1918: 1915: 1912: 1909: 1889: 1886: 1883: 1880: 1877: 1857: 1833: 1830: 1827: 1824: 1821: 1801: 1798: 1795: 1792: 1789: 1786: 1783: 1780: 1757: 1754: 1751: 1731: 1728: 1725: 1704: 1700: 1697: 1676: 1655: 1643:is nonmeagre. 1641:discrete space 1637:isolated point 1608: 1597: 1583: 1580: 1577: 1574: 1570: 1547: 1542: 1530: 1516: 1513: 1510: 1507: 1504: 1500: 1496: 1493: 1490: 1486: 1482: 1478: 1474: 1471: 1468: 1445: 1440: 1435: 1413: 1410: 1407: 1404: 1400: 1375: 1353: 1332: 1329: 1326: 1323: 1320: 1316: 1312: 1309: 1306: 1303: 1300: 1297: 1294: 1267: 1263: 1241: 1214: 1210: 1188: 1166: 1144: 1132:isolated point 1125: 1108: 1105: 1102: 1099: 1096: 1076: 1073: 1070: 1067: 1064: 1044: 1041: 1038: 1035: 1032: 1029: 1026: 1003: 1000: 997: 994: 991: 970: 966: 963: 960: 957: 954: 951: 931: 927: 923: 920: 917: 914: 911: 908: 905: 902: 899: 896: 893: 890: 887: 884: 881: 866: 863: 843:first category 819: 799: 775: 755: 731: 711: 687: 667: 640: 637: 613: 589: 569: 566: 563: 539: 536: 508: 505: 478: 458: 416: 395: 392: 364: 361: 333: 330: 304: 279: 267:first category 251: 248: 220: 217: 191: 160: 140: 137: 106: 94: 91: 15: 9: 6: 4: 3: 2: 5382: 5371: 5368: 5366: 5363: 5362: 5360: 5349: 5345: 5341: 5335: 5331: 5327: 5326:Mineola, N.Y. 5323: 5322: 5316: 5312: 5308: 5304: 5298: 5294: 5290: 5289: 5284: 5283:Rudin, Walter 5280: 5276: 5274:0-387-90508-1 5270: 5266: 5262: 5257: 5253: 5249: 5245: 5239: 5235: 5231: 5227: 5223: 5219: 5215: 5211: 5207: 5201: 5197: 5192: 5191: 5179: 5173: 5163: 5158: 5151: 5143: 5139: 5133: 5126: 5121: 5114: 5109: 5103:, p. 62. 5102: 5097: 5091:, p. 43. 5090: 5085: 5083: 5081: 5074: 5069: 5063: 5058: 5056: 5048: 5043: 5034: 5029: 5025: 5022: 5021: 5016: 5009: 5002: 4997: 4995: 4993: 4991: 4989: 4987: 4985: 4977: 4976:Bourbaki 1989 4972: 4970: 4960: 4956: 4952: 4948: 4947: 4939: 4932: 4923: 4919: 4912: 4904: 4897: 4890: 4885: 4883: 4878: 4867: 4864: 4861: 4858: 4855: 4852: 4849: 4846: 4845: 4839: 4836: 4832: 4828: 4817: 4803: 4795: 4779: 4739: 4725: 4705: 4685: 4665: 4662: 4659: 4654: 4650: 4646: 4641: 4637: 4633: 4628: 4624: 4579: 4576: 4556: 4536: 4523: 4520: 4517: 4514: 4508: 4505: 4485: 4482: 4462: 4442: 4415: 4371: 4363: 4353: 4337: 4333: 4324: 4320: 4304: 4300: 4290: 4285: 4269: 4265: 4256: 4240: 4236: 4220: 4206: 4203: 4198: 4194: 4190: 4185: 4181: 4159: 4153: 4150: 4147: 4142: 4136: 4133: 4127: 4122: 4117: 4113: 4109: 4104: 4101: 4098: 4093: 4087: 4084: 4078: 4073: 4068: 4064: 4059: 4048: 4045: 4042: 4038: 4027: 4024: 4021: 4017: 3996: 3989:with measure 3965: 3948: 3945: 3942: 3916: 3913: 3910: 3887: 3881: 3878: 3875: 3852: 3829: 3826: 3823: 3800: 3791: 3778: 3771:with measure 3755: 3752: 3749: 3726: 3706: 3698: 3694: 3676: 3673: 3670: 3659: 3632: 3630: 3620: 3607: 3604: 3582: 3578: 3557: 3554: 3549: 3545: 3541: 3536: 3532: 3528: 3525: 3505: 3485: 3482: 3477: 3473: 3469: 3464: 3460: 3439: 3419: 3416: 3413: 3404: 3390: 3370: 3350: 3330: 3321: 3319: 3315: 3305: 3304:is nonempty. 3291: 3271: 3262: 3248: 3228: 3225: 3205: 3185: 3165: 3162: 3142: 3119: 3116: 3096: 3076: 3056: 3036: 3033: 3013: 3005: 2991: 2988: 2968: 2948: 2928: 2908: 2905: 2885: 2877: 2863: 2860: 2840: 2820: 2817: 2797: 2789: 2788: 2787: 2770: 2767: 2760:is meagre in 2747: 2727: 2720:is meagre in 2707: 2687: 2684: 2664: 2656: 2642: 2639: 2632:is meagre in 2619: 2599: 2592:is meagre in 2579: 2559: 2556: 2536: 2528: 2514: 2511: 2504:is meagre in 2491: 2471: 2468: 2461:is meagre in 2448: 2440: 2439: 2438: 2424: 2421: 2401: 2381: 2361: 2358: 2351:induced from 2350: 2334: 2314: 2311: 2308: 2305: 2302: 2299: 2290: 2288: 2284: 2280: 2275: 2261: 2258: 2248: 2241: 2227: 2207: 2187: 2167: 2158: 2141: 2135: 2115: 2112: 2109: 2101: 2100:homeomorphism 2085: 2079: 2076: 2073: 2064: 2062: 2058: 2055: 2051: 2050:metric spaces 2048: 2045: 2041: 2036: 2034: 2030: 2026: 2022: 2012: 2010: 2006: 2001: 1987: 1981: 1978: 1975: 1964: 1948: 1922: 1919: 1916: 1907: 1884: 1881: 1878: 1855: 1847: 1828: 1825: 1822: 1793: 1790: 1787: 1778: 1771:In the space 1769: 1755: 1749: 1729: 1726: 1723: 1698: 1695: 1653: 1644: 1642: 1638: 1633: 1631: 1627: 1623: 1595: 1578: 1572: 1545: 1528: 1508: 1502: 1491: 1480: 1469: 1466: 1457: 1443: 1438: 1408: 1402: 1388: 1327: 1321: 1310: 1304: 1301: 1298: 1283: 1281: 1265: 1230: 1225: 1212: 1133: 1129: 1120: 1103: 1100: 1097: 1071: 1068: 1065: 1039: 1036: 1033: 1027: 1024: 1015: 998: 995: 992: 964: 958: 955: 952: 921: 915: 912: 909: 900: 894: 891: 888: 882: 879: 870: 862: 860: 856: 852: 848: 844: 839: 837: 833: 817: 797: 789: 773: 753: 746:induced from 745: 742:is given the 729: 709: 700: 685: 665: 656: 655: 651: 638: 635: 627: 611: 603: 587: 580:is meagre in 567: 561: 554: 550: 537: 534: 519: 506: 503: 476: 456: 447: 445: 437: 428: 414: 406: 393: 390: 375: 362: 359: 344: 331: 328: 302: 294: 293:nowhere dense 290: 277: 262: 249: 246: 236:meagre subset 231: 218: 215: 189: 180: 178: 174: 158: 138: 135: 127: 126:nowhere dense 122: 120: 104: 90: 88: 84: 80: 75: 73: 69: 65: 60: 58: 54: 50: 46: 42: 38: 34: 30: 26: 22: 5320: 5287: 5264: 5229: 5225: 5195: 5188:Bibliography 5172: 5150: 5142:MathOverflow 5141: 5132: 5120: 5113:Willard 2004 5108: 5096: 5068: 5047:Willard 2004 5042: 5023: 5020:Studia Math. 5018: 5008: 4950: 4944: 4931: 4921: 4911: 4905:. Macmillan. 4896: 4824: 4741: 4359: 4286: 4226: 3966: 3792: 3633: 3626: 3405: 3322: 3312:A nonmeagre 3311: 3263: 3134: 3026:is dense in 2785: 2677:is dense in 2291: 2276: 2246: 2242: 2159: 2157:is meagre. 2065: 2037: 2018: 2002: 1770: 1645: 1634: 1458: 1389: 1284: 1226: 1122:A countable 1121: 1016: 871: 868: 854: 846: 842: 840: 831: 787: 701: 657: 653: 652: 626:intersection 521: 490: 448: 439: 431: 429: 377: 346: 319:nonmeagre in 316: 264: 233: 203: 182:A subset of 181: 123: 97:Throughout, 96: 76: 61: 56: 52: 36: 32: 28: 21:mathematical 18: 5101:Oxtoby 1980 4924:. 3: 1–123. 4816:is meagre. 3695:, like the 2898:is open in 2549:is open in 2052:as well as 2040:Baire space 2021:Baire space 1716:, the sets 1630:Baire space 295:subsets of 93:Definitions 81:and of the 79:Baire space 5359:Categories 5176:S. Saito, 5162:2206.10754 5125:Rudin 1991 5089:Rudin 1991 4835:involution 3518:such that 3308:Properties 1848:, the set 1598:(that is, 1229:Cantor set 851:René Baire 841:The terms 553:complement 489:is called 376:or of the 263:or of the 202:is called 175:has empty 128:subset of 117:will be a 49:negligible 33:meager set 29:meagre set 5252:246032063 5224:(1989) . 5214:144216834 4926:, page 65 4827:null sets 4663:⋯ 4660:⊇ 4647:⊇ 4634:⊇ 4338:δ 4305:δ 4270:σ 4241:σ 4207:… 4074:− 4054:∞ 4039:⋃ 4033:∞ 4018:⋂ 3558:⋯ 3555:∪ 3542:∪ 3529:⊆ 3486:… 3417:⊆ 2309:⊆ 2303:⊆ 2287:supersets 2113:⊆ 2083:→ 2054:Hausdorff 1753:∖ 1727:∩ 1699:⊆ 1573:× 1503:× 1492:∪ 1481:× 1403:× 1390:The line 1322:∪ 1311:∩ 965:∩ 922:∩ 901:∪ 861:in 1948. 565:∖ 449:A subset 442:nonmeagre 206:meagre in 72:countably 53:nonmeagre 23:field of 5311:21163277 5285:(1991). 4842:See also 4748:For any 4289:interior 2374:The set 2347:has the 2292:Suppose 2047:(pseudo) 2044:complete 1459:The set 1285:The set 1130:without 1055:the set 942:the set 865:Examples 859:Bourbaki 602:cofinite 524:residual 493:comeagre 177:interior 5232:]. 4743:Theorem 4738:wins. 4678:Player 4364:. Let 3452:and if 2279:σ-ideal 2059:spaces 551:if its 173:closure 64:σ-ideal 39:) is a 19:In the 5348:115240 5346:  5336:  5309:  5299:  5271:  5250:  5240:  5212:  5202:  5167:(p.25) 4792:has a 4173:where 3932:since 2327:where 855:meagre 434:meagre 171:whose 41:subset 5228:[ 5157:arXiv 4941:(PDF) 4873:Notes 3316:is a 3049:then 2921:then 2833:then 2700:then 2572:then 2484:then 2098:is a 1596:space 1128:space 68:union 55:, or 43:of a 35:or a 5344:OCLC 5334:ISBN 5307:OCLC 5297:ISBN 5269:ISBN 5248:OCLC 5238:ISBN 5210:OCLC 5200:ISBN 4569:and 4455:and 4323:open 2243:The 2240:). 1742:and 1227:The 845:and 27:, a 5028:doi 4955:doi 4319:set 4255:set 3813:in 3631:. 3406:If 3320:. 3006:If 2878:If 2790:If 2657:If 2529:If 2441:If 1965:on 1632:. 1531:of 1529:set 790:of 527:in 520:or 496:in 469:of 383:in 352:of 270:in 239:of 121:. 70:of 5361:: 5342:. 5332:. 5328:: 5324:. 5305:. 5295:. 5263:. 5246:. 5208:. 5140:. 5079:^ 5054:^ 5017:. 4983:^ 4968:^ 4951:49 4949:. 4943:. 4920:. 4881:^ 4009:: 3779:1. 3707:1. 1282:. 345:a 232:a 89:. 5350:. 5313:. 5277:. 5254:. 5216:. 5165:. 5159:: 5144:. 5036:. 5030:: 5024:3 4961:. 4957:: 4804:X 4780:Q 4758:W 4726:Q 4706:X 4686:P 4666:. 4655:3 4651:W 4642:2 4638:W 4629:1 4625:W 4602:W 4580:, 4577:Q 4557:P 4537:. 4534:) 4529:W 4524:, 4521:Y 4518:, 4515:X 4512:( 4509:Z 4506:M 4486:. 4483:Y 4463:X 4443:, 4438:W 4416:Y 4394:W 4372:Y 4334:G 4301:G 4266:F 4237:F 4204:, 4199:2 4195:r 4191:, 4186:1 4182:r 4160:) 4154:m 4151:+ 4148:n 4143:) 4137:2 4134:1 4128:( 4123:+ 4118:n 4114:r 4110:, 4105:m 4102:+ 4099:n 4094:) 4088:2 4085:1 4079:( 4069:n 4065:r 4060:( 4049:1 4046:= 4043:n 4028:1 4025:= 4022:m 3997:0 3976:R 3952:] 3949:1 3946:, 3943:0 3940:[ 3920:] 3917:1 3914:, 3911:0 3908:[ 3888:, 3885:] 3882:1 3879:, 3876:0 3873:[ 3853:0 3833:] 3830:1 3827:, 3824:0 3821:[ 3801:1 3759:] 3756:1 3753:, 3750:0 3747:[ 3727:1 3680:] 3677:1 3674:, 3671:0 3668:[ 3643:R 3608:. 3605:X 3583:n 3579:S 3550:2 3546:S 3537:1 3533:S 3526:B 3506:X 3483:, 3478:2 3474:S 3470:, 3465:1 3461:S 3440:X 3420:X 3414:B 3391:X 3371:X 3351:X 3331:X 3292:X 3272:X 3249:X 3229:, 3226:X 3206:X 3186:X 3166:. 3163:X 3143:X 3120:. 3117:X 3097:A 3077:Y 3057:A 3037:, 3034:X 3014:Y 2992:. 2989:X 2969:A 2949:Y 2929:A 2909:, 2906:X 2886:Y 2864:. 2861:Y 2841:A 2821:, 2818:X 2798:A 2771:. 2768:X 2748:A 2728:Y 2708:A 2688:, 2685:X 2665:Y 2643:. 2640:X 2620:A 2600:Y 2580:A 2560:, 2557:X 2537:Y 2515:. 2512:X 2492:A 2472:, 2469:Y 2449:A 2425:. 2422:Y 2402:X 2382:A 2362:. 2359:X 2335:Y 2315:, 2312:X 2306:Y 2300:A 2262:, 2259:X 2228:X 2208:X 2188:X 2168:X 2145:) 2142:S 2139:( 2136:h 2116:X 2110:S 2086:X 2080:X 2077:: 2074:h 1988:, 1985:] 1982:1 1979:, 1976:0 1973:[ 1949:A 1929:) 1926:] 1923:1 1920:, 1917:0 1914:[ 1911:( 1908:C 1888:] 1885:1 1882:, 1879:0 1876:[ 1856:A 1832:] 1829:1 1826:, 1823:0 1820:[ 1800:) 1797:] 1794:1 1791:, 1788:0 1785:[ 1782:( 1779:C 1756:H 1750:U 1730:H 1724:U 1703:R 1696:U 1675:R 1654:H 1607:R 1582:} 1579:0 1576:{ 1569:R 1546:2 1541:R 1515:) 1512:} 1509:0 1506:{ 1499:R 1495:( 1489:) 1485:Q 1477:Q 1473:( 1470:= 1467:S 1444:. 1439:2 1434:R 1412:} 1409:0 1406:{ 1399:R 1374:R 1352:R 1331:} 1328:2 1325:{ 1319:) 1315:Q 1308:] 1305:1 1302:, 1299:0 1296:[ 1293:( 1266:. 1262:R 1240:R 1213:. 1209:R 1187:R 1165:R 1143:Q 1126:1 1124:T 1107:] 1104:2 1101:, 1098:1 1095:( 1075:] 1072:1 1069:, 1066:0 1063:[ 1043:] 1040:2 1037:, 1034:0 1031:[ 1028:= 1025:X 1002:] 999:1 996:, 993:0 990:[ 969:Q 962:] 959:3 956:, 953:2 950:[ 930:) 926:Q 919:] 916:3 913:, 910:2 907:[ 904:( 898:] 895:1 892:, 889:0 886:[ 883:= 880:X 818:X 798:X 774:A 754:X 730:X 710:A 686:X 666:X 639:. 636:X 612:X 588:X 568:A 562:X 538:, 535:X 507:, 504:X 477:X 457:A 415:X 394:. 391:X 363:, 360:X 332:, 329:X 303:X 278:X 250:, 247:X 219:, 216:X 190:X 159:X 139:, 136:X 105:X

Index

mathematical
general topology
subset
topological space
negligible
σ-ideal
union
countably
Baire space
Baire category theorem
functional analysis
topological space
nowhere dense
closure
interior
nowhere dense
complement
cofinite
intersection
subspace topology
topological vector spaces
René Baire
Bourbaki
T1 space
isolated point
Cantor set
complete metric space
isolated points
rational numbers
Baire space

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