Knowledge (XXG)

Functor

Source πŸ“

6574: 5714: 187: 179: 6821: 6841: 6831: 129: 2058: 1514: 1374: 1239: 3064:. Composition of functors is associative where defined. Identity of composition of functors is the identity functor. This shows that functors can be considered as morphisms in categories of categories, for example in the 2370: 3075:: the morphisms of a one-object category can be thought of as elements of the monoid, and composition in the category is thought of as the monoid operation. Functors between one-object categories correspond to monoid 1948: 4479: 2239: 2180: 2894: 3861: 2006: 958: 519: 4276: 4361: 1808: 4862:. In the category of topological spaces (without distinguished point), one considers homotopy classes of generic curves, but they cannot be composed unless they share an endpoint. Thus one has the 2756: 2121: 1908: 1685: 1641: 1049: 610: 3617: 4082: 2832: 2794: 80:
maps between spaces. Nowadays, functors are used throughout modern mathematics to relate various categories. Thus, functors are important in all areas within mathematics to which
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There are many constructions in mathematics that would be functors but for the fact that they "turn morphisms around" and "reverse composition". We then define a
1757: 4584: 4564: 4544: 4003: 3983: 2654: 2602: 2582: 2530: 2478: 2458: 978: 747: 539: 305: 248: 228: 208: 1134: 1843:β€”as "covariant". This terminology originates in physics, and its rationale has to do with the position of the indices ("upstairs" and "downstairs") in 6218: 3079:. So in a sense, functors between arbitrary categories are a kind of generalization of monoid homomorphisms to categories with more than one object. 2307: 2258: 5240:. Functions get mapped to group homomorphisms between free groups. Free constructions exist for many categories based on structured sets. See 6033: 6004: 5935: 5896: 5779: 6092: 4365: 6126: 1913: 2185: 2126: 6877: 2841: 5857: 165: 3773: 893: 454: 5660: 6190: 4192: 5691: 1953: 6928: 5670: 4981:, a covariant functor from the category of pointed differentiable manifolds to the category of real vector spaces. Likewise, 4683: 4280: 1766: 2705: 2095: 6211: 6117: 6059: 3469: 6415: 6370: 3065: 5847: 6844: 6784: 6054: 5681: 1850: 2182:β€”whereas it acts "in the opposite way" on the "vector coordinates" (but "in the same way" as on the basis covectors: 1646: 1602: 6943: 6834: 6620: 6484: 6392: 5301: 5282:. This is a functor which is contravariant in the first and covariant in the second argument, i.e. it is a functor 5015: 3206: 3144: 6793: 6437: 6375: 6298: 5172:
to its underlying function of sets is a functor. Functors like these, which "forget" some structure, are termed
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in order to distinguish them from contravariant ones. Note that one can also define a contravariant functor as a
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assigns to each functor its limit. The existence of this functor can be proved by realizing that it is the
6870: 6587: 6353: 6333: 6256: 6168: 6096: 5915: 5666: 5610: 262: 61: 2241:). This terminology is contrary to the one used in category theory because it is the covectors that have 6958: 6469: 6308: 5625: 5577: 5044: 3236: 615: 5975: 5713: 4136: 2607: 2535: 2483: 2407: 2375: 2053:{\displaystyle {\boldsymbol {\omega }}'={\boldsymbol {\omega }}{\boldsymbol {\Lambda }}^{\textsf {T}}.} 1538: 2063: 6908: 6281: 6276: 6172: 5919: 4906: 4821: 4608:
its dual or transpose is a contravariant functor from the category of all vector spaces over a fixed
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which is contravariant in the first argument and covariant in the second, i.e. it is a functor
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Going in the opposite direction of forgetful functors are free functors. The free functor
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can be considered as a category with a single object whose morphisms are the elements of
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is a covariant functor from the category of differentiable manifolds to the category of
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is a contravariant functor, essentially the composition of the tangent space with the
1234:{\displaystyle \mathrm {Covariant} \circ \mathrm {Covariant} \to \mathrm {Covariant} } 6978: 6933: 6688: 6520: 6397: 6323: 6193:
which generates examples of categorical constructions in the category of finite sets.
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is a natural example; it is contravariant in one argument, covariant in the other.
1698: 6703: 4858:. We thus obtain a functor from the category of pointed topological spaces to the 6025: 6683: 6555: 6425: 6160: 5411: 5241: 5084: 2999: 2939: 2917: 2123:) acts on the "covector coordinates" "in the same way" as on the basis vectors: 108: 45: 6187:
of recorded talks relevant to categories, logic and the foundations of physics.
6114: 6735: 6673: 6286: 5732: 5727: 5709: 5674: 5233: 4970: 4966: 4891:) of all real-valued continuous functions on that space. Every continuous map 4601: 2365:{\displaystyle F^{\mathrm {op} }\colon C^{\mathrm {op} }\to D^{\mathrm {op} }} 17: 6729: 6420: 6142: 5080: 3497: 96: 6178: 4622:, i.e. topological spaces with distinguished points. The objects are pairs 2060:
In this formalism it is observed that the coordinate transformation symbol
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It's not entirely clear that Haskell datatypes truly form a category. See
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Note that contravariant functors reverse the direction of composition.
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instead of the fundamental group, and this construction is functorial.
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of groups or vector spaces, construction of free groups and modules,
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https://wiki.haskell.org/Category_theory/Functor#Functors_in_Haskell
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This article is about the mathematical concept. For other uses, see
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Sheaves in geometry and logic: a first introduction to topos theory
4474:{\displaystyle \{0,1\}\mapsto f(\{0,1\})=\{f(0),f(1)\}=\{\{\},X\}.} 6645: 6196: 2969: 1943:{\displaystyle \mathbf {x} '={\boldsymbol {\Lambda }}\mathbf {x} } 185: 177: 2234:{\displaystyle \mathbf {e} ^{i}=\Lambda _{j}^{i}\mathbf {e} ^{j}} 2175:{\displaystyle \mathbf {e} _{i}=\Lambda _{i}^{j}\mathbf {e} _{j}} 6855: 6071: 6014:
Simmons, Harold (2011), "Functors and natural transformations",
5962: 2889:{\displaystyle \left(F^{\mathrm {op} }\right)^{\mathrm {op} }=F} 6859: 6585: 6238: 6200: 6136: 5097:
denotes the category of vector spaces over a fixed field, with
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variables. So, for example, a bifunctor is a multifunctor with
122: 3856:{\displaystyle F(X)={\mathcal {P}}(X)=\{\{\},\{0\},\{1\},X\}} 3071:
A small category with a single object is the same thing as a
953:{\displaystyle F(\mathrm {id} _{X})=\mathrm {id} _{F(X)}\,\!} 514:{\displaystyle F(\mathrm {id} _{X})=\mathrm {id} _{F(X)}\,\!} 76:, and maps between these algebraic objects are associated to 4879:(with continuous maps as morphisms) to the category of real 3794: 3595: 3547: 3367:
A functor that maps a category to that same category; e.g.,
6084: 4271:{\displaystyle \{0\}\mapsto f(\{0\})=\{f(0)\}=\{\{\}\},\ } 3243:) under inclusion. Like every partially ordered set, Open( 182:
A category with objects X, Y, Z and morphisms f, g, g ∘ f
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maps objects and morphisms in the identical way as does
2001:{\displaystyle \omega '_{i}=\Lambda _{i}^{j}\omega _{j}} 5420:
We can generalize the previous example to any category
4356:{\displaystyle \{1\}\mapsto f(\{1\})=\{f(1)\}=\{X\},\ } 1803:{\displaystyle \Gamma {\mathord {\left(T^{*}M\right)}}} 143: 6149:" An informal introduction to higher order categories. 2751:{\displaystyle G\colon C_{1}^{\mathrm {op} }\to C_{2}} 2116:{\displaystyle {\boldsymbol {\Lambda }}^{\textsf {T}}} 1697:
There is a convention which refers to "vectors"β€”i.e.,
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were borrowed by mathematicians from the philosophers
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is a group, then this action is a group homomorphism.
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Universal constructions often give rise to pairs of
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Contravariant functors are also occasionally called
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The composite of two functors of opposite variance:
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The composite of two functors of the same variance:
6748: 6712: 6660: 6653: 6604: 6513: 6455: 6406: 6361: 6352: 6249: 6133:" β€” by Jean-Pierre Marquis. Extensive bibliography. 5597:be categories. The collection of all functors from 138:
may be too technical for most readers to understand
5122: 4578: 4558: 4538: 4514: 4473: 4355: 4270: 4181: 4125: 4096: 4076: 4026: 3997: 3977: 3957: 3928: 3893: 3855: 3762: 3724: 3673: 3647: 3611: 3563: 3524: 3275: 3247:) forms a small category by adding a single arrow 3189: 3133: 2888: 2826: 2788: 2750: 2694: 2648: 2628: 2596: 2576: 2556: 2524: 2504: 2472: 2452: 2428: 2396: 2364: 2293: 2233: 2174: 2115: 2084: 2052: 2000: 1942: 1902: 1835: 1802: 1751: 1725: 1679: 1635: 1591: 1559: 1508: 1368: 1233: 1107: 1075: 1043: 972: 952: 876: 813: 774: 741: 670: 638: 604: 533: 513: 437: 374: 332: 299: 242: 222: 202: 6077:and the variations discussed and linked to there. 4883:is given by assigning to every topological space 4820:. This operation is compatible with the homotopy 949: 635: 510: 6115:Abstract and Concrete Categories-The Joy of Cats 4776:, with the group operation of concatenation. If 1903:{\displaystyle {x'}^{\,i}=\Lambda _{j}^{i}x^{j}} 706:Covariance and contravariance (computer science) 6137:List of academic conferences on category theory 4977:. Doing this constructions pointwise gives the 3297:. For instance, by assigning to every open set 2949:is a generalization of the functor concept to 1680:{\displaystyle F\colon C\to D^{\mathrm {op} }} 1636:{\displaystyle F\colon C^{\mathrm {op} }\to D} 1599:is a contravariant functor, they simply write 6871: 6212: 6163:. Manipulation and visualization of objects, 4875:A contravariant functor from the category of 1759:β€”as "contravariant" and to "covectors"β€”i.e., 888:such that the following two conditions hold: 449:such that the following two conditions hold: 8: 4506: 4494: 4465: 4456: 4453: 4450: 4444: 4414: 4405: 4393: 4381: 4369: 4344: 4338: 4332: 4317: 4308: 4302: 4290: 4284: 4259: 4256: 4253: 4250: 4244: 4229: 4220: 4214: 4202: 4196: 4176: 4173: 4164: 4161: 4071: 4068: 4059: 4056: 4044: 4041: 3888: 3885: 3850: 3841: 3835: 3829: 3823: 3817: 3814: 3811: 3757: 3745: 5846:Popescu, Nicolae; Popescu, Liliana (1979). 4824:and the composition of loops, and we get a 4566:in this example mapped to the power set of 210:must preserve the composition of morphisms 6878: 6864: 6856: 6840: 6830: 6657: 6601: 6582: 6358: 6246: 6235: 6219: 6205: 6197: 6181:, a YouTube channel about category theory. 3472:. This requires a suitable version of the 2968:Two important consequences of the functor 1044:{\displaystyle F(g\circ f)=F(f)\circ F(g)} 605:{\displaystyle F(g\circ f)=F(g)\circ F(f)} 6100: 5774:, New York: Springer-Verlag, p. 30, 5669:. For instance, the programming language 5109: 4571: 4551: 4531: 4486: 4367: 4282: 4194: 4138: 4109: 4089: 4039: 4010: 3990: 3970: 3941: 3906: 3868: 3793: 3792: 3775: 3737: 3695: 3689: 3660: 3628: 3612:{\displaystyle f(U)\in {\mathcal {P}}(Y)} 3594: 3593: 3576: 3546: 3545: 3537: 3505: 3262: 3170: 3114: 2870: 2869: 2855: 2854: 2843: 2808: 2807: 2801: 2776: 2775: 2763: 2742: 2725: 2724: 2719: 2707: 2686: 2673: 2661: 2641: 2616: 2615: 2609: 2589: 2569: 2544: 2543: 2537: 2517: 2492: 2491: 2485: 2465: 2445: 2416: 2415: 2409: 2384: 2383: 2377: 2352: 2351: 2334: 2333: 2316: 2315: 2309: 2274: 2225: 2220: 2213: 2208: 2195: 2190: 2187: 2166: 2161: 2154: 2149: 2136: 2131: 2128: 2107: 2106: 2105: 2100: 2097: 2076: 2071: 2065: 2041: 2040: 2039: 2034: 2028: 2016: 2013: 1992: 1982: 1977: 1961: 1955: 1935: 1930: 1918: 1915: 1894: 1884: 1879: 1866: 1865: 1855: 1852: 1824: 1818: 1784: 1774: 1773: 1768: 1741: 1706: 1667: 1666: 1648: 1617: 1616: 1604: 1572: 1547: 1546: 1540: 1465: 1421: 1389: 1387: 1337: 1293: 1249: 1247: 1202: 1170: 1138: 1136: 1088: 1056: 991: 965: 948: 933: 925: 912: 904: 895: 830: 794: 758: 734: 651: 634: 617: 552: 526: 509: 494: 486: 473: 465: 456: 391: 355: 316: 292: 235: 215: 195: 166:Learn how and when to remove this message 150:, without removing the technical details. 5949: 5833: 5809: 5800:, Routledge & Kegan, pp. 13–14. 5772:Categories for the Working Mathematician 4077:{\displaystyle \{\}\mapsto f(\{\})=\{\}} 3309:, one obtains a presheaf of algebras on 3046:then one can form the composite functor 2827:{\displaystyle G^{\mathrm {op} }\circ F} 2789:{\displaystyle G\circ F^{\mathrm {op} }} 2259:Covariance and contravariance of vectors 5821: 5759: 4586:, that need not be the case in general. 4546:. Also note that although the function 3965:is the function which sends any subset 3419:to the constant functor at that object. 3305:of real-valued continuous functions on 2834:. Note that, following the property of 2029: 2017: 877:{\displaystyle F(f)\colon F(Y)\to F(X)} 438:{\displaystyle F(f)\colon F(X)\to F(Y)} 68:, where algebraic objects (such as the 5585:Relation to other categorical concepts 4986: 3564:{\displaystyle U\in {\mathcal {P}}(X)} 3201:, the category of sets and functions, 2695:{\displaystyle F\colon C_{0}\to C_{1}} 39:Langlands program Β§ Functoriality 5999:, vol. 2 (2nd ed.), Dover, 5605:forms the objects of a category: the 5262:one can assign the abelian group Hom( 5144:which is covariant in both arguments. 3725:{\displaystyle f^{-1}(V)\subseteq X.} 3450:is complete), then the limit functor 3216:Presheaves (over a topological space) 148:make it understandable to non-experts 64:. Functors were first considered in 7: 6113:J. Adamek, H. Herrlich, G. Stecker, 5061:can be considered as an "action" of 1763:, elements of the space of sections 1701:, elements of the space of sections 6127:Stanford Encyclopedia of Philosophy 5852:. Dordrecht: Springer. p. 12. 4133:, so this could also be written as 6017:An Introduction to Category Theory 5079:Assigning to every real (complex) 3022:One can compose functors, i.e. if 2874: 2871: 2859: 2856: 2812: 2809: 2780: 2777: 2729: 2726: 2620: 2617: 2548: 2545: 2496: 2493: 2420: 2417: 2388: 2385: 2356: 2353: 2338: 2335: 2320: 2317: 2205: 2146: 2068: 1974: 1876: 1770: 1708: 1671: 1668: 1621: 1618: 1551: 1548: 1524:Ordinary functors are also called 1502: 1499: 1496: 1493: 1490: 1487: 1484: 1481: 1478: 1475: 1472: 1469: 1466: 1458: 1455: 1452: 1449: 1446: 1443: 1440: 1437: 1434: 1431: 1428: 1425: 1422: 1414: 1411: 1408: 1405: 1402: 1399: 1396: 1393: 1390: 1362: 1359: 1356: 1353: 1350: 1347: 1344: 1341: 1338: 1330: 1327: 1324: 1321: 1318: 1315: 1312: 1309: 1306: 1303: 1300: 1297: 1294: 1286: 1283: 1280: 1277: 1274: 1271: 1268: 1265: 1262: 1259: 1256: 1253: 1250: 1227: 1224: 1221: 1218: 1215: 1212: 1209: 1206: 1203: 1195: 1192: 1189: 1186: 1183: 1180: 1177: 1174: 1171: 1163: 1160: 1157: 1154: 1151: 1148: 1145: 1142: 1139: 929: 926: 908: 905: 639:{\displaystyle f\colon X\to Y\,\!} 490: 487: 469: 466: 25: 5644:generalize several of the above. 5609:. Morphisms in this category are 5576:. Functors like these are called 5178:. Another example is the functor 4182:{\displaystyle (F(f))(\{\})=\{\}} 3283:. Contravariant functors on Open( 2934:. It can be seen as a functor in 2912:) is a functor whose domain is a 2629:{\displaystyle F^{\mathrm {op} }} 2584:as a category, and similarly for 2557:{\displaystyle C^{\mathrm {op} }} 2505:{\displaystyle F^{\mathrm {op} }} 2429:{\displaystyle D^{\mathrm {op} }} 2397:{\displaystyle C^{\mathrm {op} }} 2249:, whereas vectors in general are 1560:{\displaystyle C^{\mathrm {op} }} 103:, respectively. The latter used 6839: 6829: 6820: 6819: 6572: 5712: 5661:Functor (functional programming) 2221: 2191: 2162: 2132: 2101: 2085:{\displaystyle \Lambda _{i}^{j}} 2035: 1936: 1931: 1919: 1125:Variance of functor (composite) 688:That is, functors must preserve 127: 5026:-set. Likewise, a functor from 4872:Algebra of continuous functions 4596:The map which assigns to every 3621:contravariant power set functor 3407:is defined as the functor from 3197:.In the special case when J is 3145:(Category theoretical) presheaf 5916:Gubareni, Nadezhda MikhaΔ­lovna 5798:The Logical Syntax of Language 5616:Functors are often defined by 5348:, then the group homomorphism 5304:with group homomorphisms). If 5208:(abelian group homomorphisms). 4509: 4491: 4441: 4435: 4426: 4420: 4408: 4390: 4384: 4329: 4323: 4311: 4299: 4293: 4241: 4235: 4223: 4211: 4205: 4167: 4158: 4155: 4152: 4146: 4140: 4120: 4114: 4091: 4062: 4053: 4047: 4021: 4015: 3952: 3946: 3917: 3911: 3879: 3873: 3805: 3799: 3786: 3780: 3710: 3704: 3648:{\displaystyle f\colon X\to Y} 3639: 3606: 3600: 3587: 3581: 3558: 3552: 3525:{\displaystyle f\colon X\to Y} 3516: 3190:{\displaystyle D\colon C\to J} 3181: 3134:{\displaystyle D\colon J\to C} 3125: 2987:into a commutative diagram in 2735: 2679: 2656:. For example, when composing 2344: 2294:{\displaystyle F\colon C\to D} 2285: 1720: 1711: 1659: 1627: 1592:{\displaystyle F\colon C\to D} 1583: 1462: 1334: 1199: 1108:{\displaystyle g\colon Y\to Z} 1099: 1076:{\displaystyle f\colon X\to Y} 1067: 1038: 1032: 1023: 1017: 1008: 996: 943: 937: 918: 900: 871: 865: 859: 856: 850: 841: 835: 814:{\displaystyle f\colon X\to Y} 805: 769: 763: 671:{\displaystyle g\colon Y\to Z} 662: 628: 599: 593: 584: 578: 569: 557: 504: 498: 479: 461: 432: 426: 420: 417: 411: 402: 396: 375:{\displaystyle f\colon X\to Y} 366: 327: 321: 1: 5963:https://wiki.haskell.org/Hask 5665:Functors sometimes appear in 5065:on an object in the category 4992:Group actions/representations 4954:Tangent and cotangent bundles 4720:. To every topological space 3470:Freyd adjoint functor theorem 3349:. Such a functor is called a 700:Covariance and contravariance 6026:10.1017/CBO9780511863226.004 5456:. This defines a functor to 5168:to its underlying set and a 5022:on a particular set, i.e. a 3674:{\displaystyle V\subseteq Y} 3619:. One can also consider the 3345:to the identity morphism on 3276:{\displaystyle U\subseteq V} 3066:category of small categories 2900:Bifunctors and multifunctors 6514:Constructions on categories 6055:Encyclopedia of Mathematics 5928:Algebras, rings and modules 5192:to its underlying additive 4641:is a topological space and 4522:consequently generates the 4034:, which in this case means 3415:which sends each object in 3329:which maps every object of 3165:is a contravariant functor 1726:{\displaystyle \Gamma (TM)} 7001: 6621:Higher-dimensional algebra 5658: 5302:category of abelian groups 5123:{\displaystyle V\otimes W} 4957:The map which sends every 4769:classes of loops based at 4620:pointed topological spaces 4515:{\displaystyle f(\{0,1\})} 4104:denotes the mapping under 703: 36: 29: 27:Mapping between categories 6894: 6815: 6594: 6581: 6570: 6245: 6234: 5032:category of vector spaces 4724:with distinguished point 4618:Consider the category of 3894:{\displaystyle f(0)=\{\}} 3763:{\displaystyle X=\{0,1\}} 2092:(representing the matrix 1687:) and call it a functor. 789:associates each morphism 6167:, categories, functors, 5655:Computer implementations 5640:limits. The concepts of 5051:. In general, a functor 4097:{\displaystyle \mapsto } 3411:to the functor category 2758:, one should use either 2245:in general and are thus 32:Functor (disambiguation) 6431:Cokernels and quotients 6354:Universal constructions 6169:natural transformations 6091:Hillman, Chris (2001). 5924:Kirichenko, Vladimir V. 5611:natural transformations 5436:one can assign the set 5101:as morphisms, then the 4959:differentiable manifold 4189:. For the other values, 3655:to the map which sends 3532:to the map which sends 3109:is a covariant functor 3014:) is an isomorphism in 2564:does not coincide with 729:associates each object 6929:Essentially surjective 6588:Higher category theory 6334:Natural transformation 6093:"A Categorical Primer" 5667:functional programming 5578:representable functors 5417:Representable functors 5204:) become morphisms in 5124: 5014:is then nothing but a 4580: 4560: 4540: 4516: 4475: 4357: 4272: 4183: 4127: 4098: 4078: 4028: 3999: 3979: 3959: 3930: 3929:{\displaystyle f(1)=X} 3895: 3857: 3764: 3726: 3675: 3649: 3613: 3565: 3526: 3482:The power set functor 3341:and every morphism in 3277: 3191: 3135: 2890: 2828: 2790: 2752: 2696: 2650: 2636:is distinguished from 2630: 2598: 2578: 2558: 2526: 2506: 2474: 2454: 2430: 2398: 2366: 2295: 2235: 2176: 2117: 2086: 2054: 2002: 1944: 1904: 1837: 1836:{\displaystyle T^{*}M} 1804: 1753: 1727: 1681: 1637: 1593: 1561: 1510: 1370: 1235: 1109: 1077: 1045: 974: 954: 878: 815: 776: 743: 672: 640: 606: 535: 515: 439: 376: 334: 301: 250: 244: 224: 204: 183: 5978:for more information. 5125: 5045:linear representation 4805:can be composed with 4794:, then every loop in 4731:, one can define the 4581: 4561: 4541: 4517: 4476: 4358: 4273: 4184: 4128: 4099: 4079: 4029: 4000: 3980: 3960: 3931: 3896: 3858: 3765: 3727: 3676: 3650: 3614: 3566: 3527: 3496:maps each set to its 3278: 3237:partially ordered set 3192: 3136: 2891: 2829: 2791: 2753: 2697: 2651: 2631: 2599: 2579: 2559: 2527: 2507: 2475: 2455: 2431: 2399: 2367: 2296: 2236: 2177: 2118: 2087: 2055: 2003: 1945: 1905: 1838: 1805: 1754: 1728: 1682: 1638: 1594: 1562: 1511: 1371: 1236: 1110: 1078: 1046: 975: 955: 879: 816: 777: 744: 712:contravariant functor 673: 641: 607: 536: 516: 440: 377: 335: 302: 245: 225: 205: 189: 181: 6457:Algebraic categories 6191:Interactive Web page 6173:universal properties 5849:Theory of categories 5618:universal properties 5270:) consisting of all 5108: 4907:algebra homomorphism 4881:associative algebras 4822:equivalence relation 4570: 4550: 4530: 4485: 4366: 4281: 4193: 4137: 4126:{\displaystyle F(f)} 4108: 4088: 4038: 4027:{\displaystyle f(U)} 4009: 3989: 3969: 3958:{\displaystyle F(f)} 3940: 3905: 3867: 3774: 3736: 3688: 3659: 3627: 3575: 3536: 3504: 3261: 3169: 3113: 3101:, a diagram of type 2842: 2800: 2762: 2706: 2660: 2640: 2608: 2588: 2568: 2536: 2516: 2484: 2464: 2444: 2408: 2376: 2308: 2273: 2186: 2127: 2096: 2064: 2012: 1954: 1914: 1851: 1817: 1767: 1740: 1705: 1647: 1603: 1571: 1539: 1386: 1246: 1135: 1087: 1055: 990: 964: 894: 829: 793: 775:{\displaystyle F(X)} 757: 733: 650: 616: 551: 525: 455: 390: 354: 333:{\displaystyle F(X)} 315: 291: 234: 214: 194: 72:) are associated to 6626:Homotopy hypothesis 6304:Commutative diagram 6020:, pp. 72–107, 5912:Hazewinkel, Michiel 5620:; examples are the 5272:group homomorphisms 5247:Homomorphism groups 5083:its real (complex) 4809:to yield a loop in 3432:, if every functor 3303:associative algebra 2981:commutative diagram 2916:. For example, the 2734: 2438:opposite categories 2218: 2159: 2081: 1987: 1969: 1889: 6339:Universal property 6141:Baez, John, 1996," 6120:2015-04-21 at the 5881:Mac Lane, Saunders 5812:, p. 19, def. 1.2. 5768:Mac Lane, Saunders 5720:Mathematics portal 5688:polytypic function 5613:between functors. 5448:of morphisms from 5202:ring homomorphisms 5175:forgetful functors 5170:group homomorphism 5147:Forgetful functors 5130:defines a functor 5120: 5087:defines a functor. 4877:topological spaces 4860:category of groups 4826:group homomorphism 4652:. A morphism from 4576: 4556: 4536: 4512: 4471: 4353: 4268: 4179: 4123: 4094: 4074: 4024: 3995: 3975: 3955: 3926: 3891: 3853: 3760: 3722: 3671: 3645: 3609: 3561: 3522: 3500:and each function 3479:Power sets functor 3369:polynomial functor 3333:to a fixed object 3273: 3187: 3131: 3038:is a functor from 3026:is a functor from 2886: 2824: 2786: 2748: 2715: 2692: 2646: 2626: 2594: 2574: 2554: 2522: 2502: 2470: 2450: 2426: 2394: 2362: 2291: 2253:since they can be 2231: 2204: 2172: 2145: 2113: 2082: 2067: 2050: 1998: 1973: 1957: 1940: 1900: 1875: 1833: 1800: 1752:{\displaystyle TM} 1749: 1723: 1677: 1633: 1589: 1557: 1526:covariant functors 1506: 1366: 1231: 1105: 1073: 1051:for all morphisms 1041: 970: 950: 874: 811: 772: 739: 725:as a mapping that 690:identity morphisms 668: 636: 612:for all morphisms 602: 531: 511: 435: 372: 330: 297: 280:is a mapping that 251: 240: 220: 200: 184: 74:topological spaces 66:algebraic topology 6972: 6971: 6944:Full and faithful 6853: 6852: 6811: 6810: 6807: 6806: 6789:monoidal category 6744: 6743: 6616:Enriched category 6568: 6567: 6564: 6563: 6541:Quotient category 6536:Opposite category 6451: 6450: 6035:978-1-107-01087-1 6006:978-0-486-47187-7 5965:for more details. 5937:978-1-4020-2690-4 5898:978-0-387-97710-2 5836:, pp. 19–20. 5824:, Exercise 3.1.4. 5781:978-3-540-90035-1 5642:limit and colimit 5514:are morphisms in 5344:are morphisms in 5006:. A functor from 4790:is a morphism of 4733:fundamental group 4615:Fundamental group 4591:Dual vector space 4579:{\displaystyle X} 4559:{\displaystyle f} 4539:{\displaystyle X} 4352: 4267: 3998:{\displaystyle X} 3978:{\displaystyle U} 3468:and invoking the 3446:(for instance if 3225:topological space 2908:(also known as a 2836:opposite category 2649:{\displaystyle F} 2597:{\displaystyle D} 2577:{\displaystyle C} 2525:{\displaystyle F} 2480:. By definition, 2473:{\displaystyle D} 2453:{\displaystyle C} 2109: 2043: 1534:opposite category 973:{\displaystyle X} 960:for every object 742:{\displaystyle X} 534:{\displaystyle X} 521:for every object 300:{\displaystyle X} 243:{\displaystyle f} 223:{\displaystyle g} 203:{\displaystyle F} 176: 175: 168: 70:fundamental group 16:(Redirected from 6992: 6880: 6873: 6866: 6857: 6843: 6842: 6833: 6832: 6823: 6822: 6658: 6636:Simplex category 6611:Categorification 6602: 6583: 6576: 6546:Product category 6531:Kleisli category 6526:Functor category 6371:Terminal objects 6359: 6294:Adjoint functors 6247: 6236: 6221: 6214: 6207: 6198: 6110: 6105:. Archived from 6104: 6063: 6038: 6009: 5993:Jacobson, Nathan 5979: 5972: 5966: 5959: 5953: 5947: 5941: 5940: 5920:Gubareni, Nadiya 5908: 5902: 5901: 5877: 5871: 5870: 5868: 5866: 5843: 5837: 5831: 5825: 5819: 5813: 5807: 5801: 5791: 5785: 5784: 5764: 5738:Functor category 5722: 5717: 5716: 5684: 5679: 5649:adjoint functors 5607:functor category 5575: 5557: 5513: 5493: 5473: 5447: 5424:. To every pair 5409: 5391: 5359: 5343: 5323: 5295: 5228:sends every set 5227: 5187: 5163: 5143: 5129: 5127: 5126: 5121: 5060: 4942: 4923: 4904: 4857: 4842: 4813:with base point 4798:with base point 4789: 4760: 4719: 4699: 4681: 4666: 4636: 4593: 4592: 4585: 4583: 4582: 4577: 4565: 4563: 4562: 4557: 4545: 4543: 4542: 4537: 4524:trivial topology 4521: 4519: 4518: 4513: 4480: 4478: 4477: 4472: 4362: 4360: 4359: 4354: 4350: 4277: 4275: 4274: 4269: 4265: 4188: 4186: 4185: 4180: 4132: 4130: 4129: 4124: 4103: 4101: 4100: 4095: 4083: 4081: 4080: 4075: 4033: 4031: 4030: 4025: 4004: 4002: 4001: 3996: 3984: 3982: 3981: 3976: 3964: 3962: 3961: 3956: 3935: 3933: 3932: 3927: 3900: 3898: 3897: 3892: 3862: 3860: 3859: 3854: 3798: 3797: 3769: 3767: 3766: 3761: 3732:For example, if 3731: 3729: 3728: 3723: 3703: 3702: 3680: 3678: 3677: 3672: 3654: 3652: 3651: 3646: 3618: 3616: 3615: 3610: 3599: 3598: 3570: 3568: 3567: 3562: 3551: 3550: 3531: 3529: 3528: 3523: 3495: 3466:diagonal functor 3459: 3441: 3405:diagonal functor 3400:Diagonal functor 3377:Identity functor 3328: 3316:Constant functor 3282: 3280: 3279: 3274: 3256: 3196: 3194: 3193: 3188: 3140: 3138: 3137: 3132: 3055: 2979:transforms each 2959: 2933: 2914:product category 2895: 2893: 2892: 2887: 2879: 2878: 2877: 2868: 2864: 2863: 2862: 2833: 2831: 2830: 2825: 2817: 2816: 2815: 2795: 2793: 2792: 2787: 2785: 2784: 2783: 2757: 2755: 2754: 2749: 2747: 2746: 2733: 2732: 2723: 2701: 2699: 2698: 2693: 2691: 2690: 2678: 2677: 2655: 2653: 2652: 2647: 2635: 2633: 2632: 2627: 2625: 2624: 2623: 2603: 2601: 2600: 2595: 2583: 2581: 2580: 2575: 2563: 2561: 2560: 2555: 2553: 2552: 2551: 2531: 2529: 2528: 2523: 2511: 2509: 2508: 2503: 2501: 2500: 2499: 2479: 2477: 2476: 2471: 2459: 2457: 2456: 2451: 2435: 2433: 2432: 2427: 2425: 2424: 2423: 2403: 2401: 2400: 2395: 2393: 2392: 2391: 2371: 2369: 2368: 2363: 2361: 2360: 2359: 2343: 2342: 2341: 2325: 2324: 2323: 2303:opposite functor 2300: 2298: 2297: 2292: 2265:Opposite functor 2240: 2238: 2237: 2232: 2230: 2229: 2224: 2217: 2212: 2200: 2199: 2194: 2181: 2179: 2178: 2173: 2171: 2170: 2165: 2158: 2153: 2141: 2140: 2135: 2122: 2120: 2119: 2114: 2112: 2111: 2110: 2104: 2091: 2089: 2088: 2083: 2080: 2075: 2059: 2057: 2056: 2051: 2046: 2045: 2044: 2038: 2032: 2024: 2020: 2007: 2005: 2004: 1999: 1997: 1996: 1986: 1981: 1965: 1949: 1947: 1946: 1941: 1939: 1934: 1926: 1922: 1909: 1907: 1906: 1901: 1899: 1898: 1888: 1883: 1871: 1870: 1864: 1863: 1842: 1840: 1839: 1834: 1829: 1828: 1812:cotangent bundle 1809: 1807: 1806: 1801: 1799: 1798: 1797: 1793: 1789: 1788: 1758: 1756: 1755: 1750: 1732: 1730: 1729: 1724: 1686: 1684: 1683: 1678: 1676: 1675: 1674: 1642: 1640: 1639: 1634: 1626: 1625: 1624: 1598: 1596: 1595: 1590: 1566: 1564: 1563: 1558: 1556: 1555: 1554: 1515: 1513: 1512: 1507: 1505: 1461: 1417: 1375: 1373: 1372: 1367: 1365: 1333: 1289: 1240: 1238: 1237: 1232: 1230: 1198: 1166: 1114: 1112: 1111: 1106: 1082: 1080: 1079: 1074: 1050: 1048: 1047: 1042: 979: 977: 976: 971: 959: 957: 956: 951: 947: 946: 932: 917: 916: 911: 883: 881: 880: 875: 825:with a morphism 820: 818: 817: 812: 781: 779: 778: 773: 748: 746: 745: 740: 677: 675: 674: 669: 645: 643: 642: 637: 611: 609: 608: 603: 540: 538: 537: 532: 520: 518: 517: 512: 508: 507: 493: 478: 477: 472: 444: 442: 441: 436: 381: 379: 378: 373: 347:associates each 339: 337: 336: 331: 306: 304: 303: 298: 284:associates each 249: 247: 246: 241: 229: 227: 226: 221: 209: 207: 206: 201: 171: 164: 160: 157: 151: 131: 130: 123: 21: 7000: 6999: 6995: 6994: 6993: 6991: 6990: 6989: 6975: 6974: 6973: 6968: 6890: 6884: 6854: 6849: 6803: 6773: 6740: 6717: 6708: 6665: 6649: 6600: 6590: 6577: 6560: 6509: 6447: 6416:Initial objects 6402: 6348: 6241: 6230: 6228:Category theory 6225: 6157:category theory 6131:Category Theory 6122:Wayback Machine 6090: 6048: 6045: 6036: 6013: 6007: 5991: 5988: 5983: 5982: 5973: 5969: 5960: 5956: 5952:, p. 20, ex. 2. 5950:Jacobson (2009) 5948: 5944: 5938: 5910: 5909: 5905: 5899: 5879: 5878: 5874: 5864: 5862: 5860: 5845: 5844: 5840: 5834:Jacobson (2009) 5832: 5828: 5820: 5816: 5810:Jacobson (2009) 5808: 5804: 5792: 5788: 5782: 5766: 5765: 5761: 5756: 5718: 5711: 5708: 5682: 5677: 5663: 5657: 5587: 5559: 5555: 5548: 5541: 5534: 5519: 5518:, then the map 5512: 5505: 5495: 5492: 5485: 5475: 5461: 5437: 5393: 5389: 5382: 5375: 5368: 5361: 5349: 5342: 5335: 5325: 5322: 5315: 5305: 5283: 5215: 5196:. Morphisms in 5179: 5151: 5131: 5106: 5105: 5090:Tensor products 5052: 5042: 4983:cotangent space 4925: 4909: 4892: 4855: 4844: 4840: 4829: 4819: 4804: 4777: 4775: 4758: 4747: 4743: 4741: 4730: 4718: 4711: 4701: 4687: 4679: 4668: 4664: 4653: 4647: 4634: 4623: 4590: 4589: 4568: 4567: 4548: 4547: 4528: 4527: 4483: 4482: 4364: 4363: 4279: 4278: 4191: 4190: 4135: 4134: 4106: 4105: 4086: 4085: 4036: 4035: 4007: 4006: 3987: 3986: 3967: 3966: 3938: 3937: 3903: 3902: 3865: 3864: 3772: 3771: 3734: 3733: 3691: 3686: 3685: 3657: 3656: 3625: 3624: 3573: 3572: 3534: 3533: 3502: 3501: 3483: 3474:axiom of choice 3451: 3433: 3396: 3390: 3378: 3364: 3320: 3259: 3258: 3257:if and only if 3248: 3167: 3166: 3149:For categories 3111: 3110: 3093:For categories 3085: 3047: 2966: 2954: 2938:arguments. The 2921: 2920:is of the type 2902: 2850: 2846: 2845: 2840: 2839: 2803: 2798: 2797: 2771: 2760: 2759: 2738: 2704: 2703: 2682: 2669: 2658: 2657: 2638: 2637: 2611: 2606: 2605: 2586: 2585: 2566: 2565: 2539: 2534: 2533: 2514: 2513: 2487: 2482: 2481: 2462: 2461: 2442: 2441: 2411: 2406: 2405: 2379: 2374: 2373: 2347: 2329: 2311: 2306: 2305: 2271: 2270: 2267: 2219: 2189: 2184: 2183: 2160: 2130: 2125: 2124: 2099: 2094: 2093: 2062: 2061: 2033: 2015: 2010: 2009: 1988: 1952: 1951: 1917: 1912: 1911: 1890: 1856: 1854: 1849: 1848: 1820: 1815: 1814: 1780: 1779: 1775: 1765: 1764: 1738: 1737: 1703: 1702: 1662: 1645: 1644: 1612: 1601: 1600: 1569: 1568: 1542: 1537: 1536: 1532:functor on the 1384: 1383: 1244: 1243: 1133: 1132: 1085: 1084: 1053: 1052: 988: 987: 962: 961: 924: 903: 892: 891: 827: 826: 791: 790: 755: 754: 753:with an object 731: 730: 708: 702: 648: 647: 614: 613: 549: 548: 523: 522: 485: 464: 453: 452: 388: 387: 352: 351: 313: 312: 289: 288: 232: 231: 212: 211: 192: 191: 172: 161: 155: 152: 144:help improve it 141: 132: 128: 121: 82:category theory 50:category theory 48:, specifically 42: 35: 28: 23: 22: 15: 12: 11: 5: 6998: 6996: 6988: 6987: 6977: 6976: 6970: 6969: 6967: 6966: 6961: 6956: 6951: 6946: 6941: 6936: 6931: 6926: 6921: 6916: 6911: 6906: 6901: 6895: 6892: 6891: 6885: 6883: 6882: 6875: 6868: 6860: 6851: 6850: 6848: 6847: 6837: 6827: 6816: 6813: 6812: 6809: 6808: 6805: 6804: 6802: 6801: 6796: 6791: 6777: 6771: 6766: 6761: 6755: 6753: 6746: 6745: 6742: 6741: 6739: 6738: 6733: 6722: 6720: 6715: 6710: 6709: 6707: 6706: 6701: 6696: 6691: 6686: 6681: 6670: 6668: 6663: 6655: 6651: 6650: 6648: 6643: 6641:String diagram 6638: 6633: 6631:Model category 6628: 6623: 6618: 6613: 6608: 6606: 6599: 6598: 6595: 6592: 6591: 6586: 6579: 6578: 6571: 6569: 6566: 6565: 6562: 6561: 6559: 6558: 6553: 6551:Comma category 6548: 6543: 6538: 6533: 6528: 6523: 6517: 6515: 6511: 6510: 6508: 6507: 6497: 6487: 6485:Abelian groups 6482: 6477: 6472: 6467: 6461: 6459: 6453: 6452: 6449: 6448: 6446: 6445: 6440: 6435: 6434: 6433: 6423: 6418: 6412: 6410: 6404: 6403: 6401: 6400: 6395: 6390: 6389: 6388: 6378: 6373: 6367: 6365: 6356: 6350: 6349: 6347: 6346: 6341: 6336: 6331: 6326: 6321: 6316: 6311: 6306: 6301: 6296: 6291: 6290: 6289: 6284: 6279: 6274: 6269: 6264: 6253: 6251: 6243: 6242: 6239: 6232: 6231: 6226: 6224: 6223: 6216: 6209: 6201: 6195: 6194: 6188: 6182: 6176: 6150: 6139: 6134: 6124: 6111: 6109:on 1997-05-03. 6102:10.1.1.24.3264 6088: 6078: 6064: 6044: 6043:External links 6041: 6040: 6039: 6034: 6011: 6005: 5987: 5984: 5981: 5980: 5967: 5954: 5942: 5936: 5903: 5897: 5885:Moerdijk, Ieke 5872: 5858: 5838: 5826: 5822:Simmons (2011) 5814: 5802: 5794:Carnap, Rudolf 5786: 5780: 5758: 5757: 5755: 5752: 5751: 5750: 5745: 5740: 5735: 5730: 5724: 5723: 5707: 5704: 5659:Main article: 5656: 5653: 5630:direct product 5622:tensor product 5586: 5583: 5582: 5581: 5553: 5546: 5539: 5532: 5510: 5503: 5490: 5483: 5432:of objects in 5418: 5415: 5387: 5380: 5373: 5366: 5340: 5333: 5320: 5313: 5260:abelian groups 5250:To every pair 5248: 5245: 5212: 5209: 5148: 5145: 5119: 5116: 5113: 5103:tensor product 5091: 5088: 5077: 5074: 5038: 4993: 4990: 4975:vector bundles 4963:tangent bundle 4955: 4952: 4887:the algebra C( 4873: 4870: 4853: 4838: 4817: 4802: 4792:pointed spaces 4773: 4761:. This is the 4756: 4745: 4739: 4728: 4716: 4709: 4682:is given by a 4677: 4662: 4648:is a point in 4645: 4632: 4616: 4613: 4594: 4587: 4575: 4555: 4535: 4511: 4508: 4505: 4502: 4499: 4496: 4493: 4490: 4470: 4467: 4464: 4461: 4458: 4455: 4452: 4449: 4446: 4443: 4440: 4437: 4434: 4431: 4428: 4425: 4422: 4419: 4416: 4413: 4410: 4407: 4404: 4401: 4398: 4395: 4392: 4389: 4386: 4383: 4380: 4377: 4374: 4371: 4349: 4346: 4343: 4340: 4337: 4334: 4331: 4328: 4325: 4322: 4319: 4316: 4313: 4310: 4307: 4304: 4301: 4298: 4295: 4292: 4289: 4286: 4264: 4261: 4258: 4255: 4252: 4249: 4246: 4243: 4240: 4237: 4234: 4231: 4228: 4225: 4222: 4219: 4216: 4213: 4210: 4207: 4204: 4201: 4198: 4178: 4175: 4172: 4169: 4166: 4163: 4160: 4157: 4154: 4151: 4148: 4145: 4142: 4122: 4119: 4116: 4113: 4093: 4073: 4070: 4067: 4064: 4061: 4058: 4055: 4052: 4049: 4046: 4043: 4023: 4020: 4017: 4014: 3994: 3974: 3954: 3951: 3948: 3945: 3925: 3922: 3919: 3916: 3913: 3910: 3890: 3887: 3884: 3881: 3878: 3875: 3872: 3852: 3849: 3846: 3843: 3840: 3837: 3834: 3831: 3828: 3825: 3822: 3819: 3816: 3813: 3810: 3807: 3804: 3801: 3796: 3791: 3788: 3785: 3782: 3779: 3759: 3756: 3753: 3750: 3747: 3744: 3741: 3721: 3718: 3715: 3712: 3709: 3706: 3701: 3698: 3694: 3670: 3667: 3664: 3644: 3641: 3638: 3635: 3632: 3608: 3605: 3602: 3597: 3592: 3589: 3586: 3583: 3580: 3560: 3557: 3554: 3549: 3544: 3541: 3521: 3518: 3515: 3512: 3509: 3480: 3477: 3427:index category 3423: 3420: 3401: 3398: 3392: 3386: 3379: 3376: 3374: 3372: 3365: 3362: 3360: 3358: 3317: 3314: 3272: 3269: 3266: 3217: 3214: 3186: 3183: 3180: 3177: 3174: 3147: 3142: 3130: 3127: 3124: 3121: 3118: 3091: 3084: 3081: 3020: 3019: 2992: 2965: 2962: 2910:binary functor 2901: 2898: 2885: 2882: 2876: 2873: 2867: 2861: 2858: 2853: 2849: 2823: 2820: 2814: 2811: 2806: 2782: 2779: 2774: 2770: 2767: 2745: 2741: 2737: 2731: 2728: 2722: 2718: 2714: 2711: 2689: 2685: 2681: 2676: 2672: 2668: 2665: 2645: 2622: 2619: 2614: 2593: 2573: 2550: 2547: 2542: 2521: 2498: 2495: 2490: 2469: 2449: 2422: 2419: 2414: 2390: 2387: 2382: 2358: 2355: 2350: 2346: 2340: 2337: 2332: 2328: 2322: 2319: 2314: 2290: 2287: 2284: 2281: 2278: 2269:Every functor 2266: 2263: 2255:pushed forward 2228: 2223: 2216: 2211: 2207: 2203: 2198: 2193: 2169: 2164: 2157: 2152: 2148: 2144: 2139: 2134: 2103: 2079: 2074: 2070: 2049: 2037: 2031: 2027: 2023: 2019: 1995: 1991: 1985: 1980: 1976: 1972: 1968: 1964: 1960: 1938: 1933: 1929: 1925: 1921: 1897: 1893: 1887: 1882: 1878: 1874: 1869: 1862: 1859: 1832: 1827: 1823: 1796: 1792: 1787: 1783: 1778: 1772: 1748: 1745: 1735:tangent bundle 1722: 1719: 1716: 1713: 1710: 1673: 1670: 1665: 1661: 1658: 1655: 1652: 1643:(or sometimes 1632: 1629: 1623: 1620: 1615: 1611: 1608: 1588: 1585: 1582: 1579: 1576: 1553: 1550: 1545: 1519: 1518: 1517: 1516: 1504: 1501: 1498: 1495: 1492: 1489: 1486: 1483: 1480: 1477: 1474: 1471: 1468: 1464: 1460: 1457: 1454: 1451: 1448: 1445: 1442: 1439: 1436: 1433: 1430: 1427: 1424: 1420: 1416: 1413: 1410: 1407: 1404: 1401: 1398: 1395: 1392: 1378: 1377: 1376: 1364: 1361: 1358: 1355: 1352: 1349: 1346: 1343: 1340: 1336: 1332: 1329: 1326: 1323: 1320: 1317: 1314: 1311: 1308: 1305: 1302: 1299: 1296: 1292: 1288: 1285: 1282: 1279: 1276: 1273: 1270: 1267: 1264: 1261: 1258: 1255: 1252: 1241: 1229: 1226: 1223: 1220: 1217: 1214: 1211: 1208: 1205: 1201: 1197: 1194: 1191: 1188: 1185: 1182: 1179: 1176: 1173: 1169: 1165: 1162: 1159: 1156: 1153: 1150: 1147: 1144: 1141: 1123: 1122: 1121: 1120: 1104: 1101: 1098: 1095: 1092: 1072: 1069: 1066: 1063: 1060: 1040: 1037: 1034: 1031: 1028: 1025: 1022: 1019: 1016: 1013: 1010: 1007: 1004: 1001: 998: 995: 985: 969: 945: 942: 939: 936: 931: 928: 923: 920: 915: 910: 907: 902: 899: 873: 870: 867: 864: 861: 858: 855: 852: 849: 846: 843: 840: 837: 834: 810: 807: 804: 801: 798: 787: 771: 768: 765: 762: 738: 701: 698: 696:of morphisms. 686: 685: 684: 683: 667: 664: 661: 658: 655: 633: 630: 627: 624: 621: 601: 598: 595: 592: 589: 586: 583: 580: 577: 574: 571: 568: 565: 562: 559: 556: 546: 530: 506: 503: 500: 497: 492: 489: 484: 481: 476: 471: 468: 463: 460: 434: 431: 428: 425: 422: 419: 416: 413: 410: 407: 404: 401: 398: 395: 386:to a morphism 371: 368: 365: 362: 359: 345: 329: 326: 323: 320: 296: 239: 219: 199: 174: 173: 135: 133: 126: 120: 117: 26: 24: 14: 13: 10: 9: 6: 4: 3: 2: 6997: 6986: 6983: 6982: 6980: 6965: 6962: 6960: 6959:Representable 6957: 6955: 6952: 6950: 6947: 6945: 6942: 6940: 6937: 6935: 6932: 6930: 6927: 6925: 6922: 6920: 6917: 6915: 6912: 6910: 6907: 6905: 6902: 6900: 6897: 6896: 6893: 6888: 6881: 6876: 6874: 6869: 6867: 6862: 6861: 6858: 6846: 6838: 6836: 6828: 6826: 6818: 6817: 6814: 6800: 6797: 6795: 6792: 6790: 6786: 6782: 6778: 6776: 6774: 6767: 6765: 6762: 6760: 6757: 6756: 6754: 6751: 6747: 6737: 6734: 6731: 6727: 6724: 6723: 6721: 6719: 6711: 6705: 6702: 6700: 6697: 6695: 6692: 6690: 6689:Tetracategory 6687: 6685: 6682: 6679: 6678:pseudofunctor 6675: 6672: 6671: 6669: 6667: 6659: 6656: 6652: 6647: 6644: 6642: 6639: 6637: 6634: 6632: 6629: 6627: 6624: 6622: 6619: 6617: 6614: 6612: 6609: 6607: 6603: 6597: 6596: 6593: 6589: 6584: 6580: 6575: 6557: 6554: 6552: 6549: 6547: 6544: 6542: 6539: 6537: 6534: 6532: 6529: 6527: 6524: 6522: 6521:Free category 6519: 6518: 6516: 6512: 6505: 6504:Vector spaces 6501: 6498: 6495: 6491: 6488: 6486: 6483: 6481: 6478: 6476: 6473: 6471: 6468: 6466: 6463: 6462: 6460: 6458: 6454: 6444: 6441: 6439: 6436: 6432: 6429: 6428: 6427: 6424: 6422: 6419: 6417: 6414: 6413: 6411: 6409: 6405: 6399: 6398:Inverse limit 6396: 6394: 6391: 6387: 6384: 6383: 6382: 6379: 6377: 6374: 6372: 6369: 6368: 6366: 6364: 6360: 6357: 6355: 6351: 6345: 6342: 6340: 6337: 6335: 6332: 6330: 6327: 6325: 6324:Kan extension 6322: 6320: 6317: 6315: 6312: 6310: 6307: 6305: 6302: 6300: 6297: 6295: 6292: 6288: 6285: 6283: 6280: 6278: 6275: 6273: 6270: 6268: 6265: 6263: 6260: 6259: 6258: 6255: 6254: 6252: 6248: 6244: 6237: 6233: 6229: 6222: 6217: 6215: 6210: 6208: 6203: 6202: 6199: 6192: 6189: 6186: 6185:Video archive 6183: 6180: 6177: 6174: 6170: 6166: 6162: 6158: 6154: 6151: 6148: 6146: 6140: 6138: 6135: 6132: 6128: 6125: 6123: 6119: 6116: 6112: 6108: 6103: 6098: 6094: 6089: 6086: 6082: 6079: 6076: 6074: 6069: 6065: 6061: 6057: 6056: 6051: 6047: 6046: 6042: 6037: 6031: 6027: 6023: 6019: 6018: 6012: 6008: 6002: 5998: 5997:Basic algebra 5994: 5990: 5989: 5985: 5977: 5971: 5968: 5964: 5958: 5955: 5951: 5946: 5943: 5939: 5933: 5929: 5925: 5921: 5917: 5913: 5907: 5904: 5900: 5894: 5890: 5886: 5882: 5876: 5873: 5861: 5859:9789400995505 5855: 5851: 5850: 5842: 5839: 5835: 5830: 5827: 5823: 5818: 5815: 5811: 5806: 5803: 5799: 5795: 5790: 5787: 5783: 5777: 5773: 5769: 5763: 5760: 5753: 5749: 5748:Pseudofunctor 5746: 5744: 5743:Kan extension 5741: 5739: 5736: 5734: 5731: 5729: 5726: 5725: 5721: 5715: 5710: 5705: 5703: 5701: 5697: 5693: 5689: 5685: 5676: 5672: 5668: 5662: 5654: 5652: 5650: 5645: 5643: 5639: 5635: 5631: 5627: 5623: 5619: 5614: 5612: 5608: 5604: 5600: 5596: 5592: 5584: 5579: 5574: 5570: 5566: 5562: 5552: 5545: 5538: 5531: 5528:) : Hom( 5527: 5523: 5517: 5509: 5502: 5498: 5489: 5482: 5478: 5472: 5468: 5464: 5459: 5455: 5451: 5445: 5441: 5435: 5431: 5427: 5423: 5419: 5416: 5413: 5408: 5404: 5400: 5396: 5386: 5379: 5372: 5365: 5357: 5353: 5347: 5339: 5332: 5328: 5319: 5312: 5308: 5303: 5299: 5294: 5290: 5286: 5281: 5277: 5273: 5269: 5265: 5261: 5257: 5253: 5249: 5246: 5243: 5239: 5236:generated by 5235: 5231: 5226: 5222: 5218: 5213: 5211:Free functors 5210: 5207: 5203: 5199: 5195: 5194:abelian group 5191: 5188:which maps a 5186: 5182: 5177: 5176: 5171: 5167: 5164:which maps a 5162: 5158: 5154: 5149: 5146: 5142: 5138: 5134: 5117: 5114: 5111: 5104: 5100: 5096: 5092: 5089: 5086: 5082: 5078: 5075: 5072: 5068: 5064: 5059: 5055: 5050: 5046: 5041: 5037: 5033: 5029: 5025: 5021: 5017: 5013: 5009: 5005: 5001: 4998: 4994: 4991: 4988: 4984: 4980: 4979:tangent space 4976: 4972: 4968: 4964: 4960: 4956: 4953: 4950: 4946: 4941: 4937: 4933: 4929: 4921: 4917: 4913: 4908: 4903: 4899: 4895: 4890: 4886: 4882: 4878: 4874: 4871: 4868: 4867: 4861: 4852: 4848: 4837: 4833: 4827: 4823: 4816: 4812: 4808: 4801: 4797: 4793: 4788: 4784: 4780: 4772: 4768: 4764: 4755: 4751: 4738: 4734: 4727: 4723: 4715: 4708: 4704: 4698: 4694: 4690: 4685: 4676: 4672: 4661: 4657: 4651: 4644: 4640: 4631: 4627: 4621: 4617: 4614: 4611: 4607: 4604:and to every 4603: 4599: 4595: 4588: 4573: 4553: 4533: 4525: 4503: 4500: 4497: 4488: 4468: 4462: 4459: 4447: 4438: 4432: 4429: 4423: 4417: 4411: 4402: 4399: 4396: 4387: 4378: 4375: 4372: 4347: 4341: 4335: 4326: 4320: 4314: 4305: 4296: 4287: 4262: 4247: 4238: 4232: 4226: 4217: 4208: 4199: 4170: 4149: 4143: 4117: 4111: 4065: 4050: 4018: 4012: 4005:to its image 3992: 3972: 3949: 3943: 3923: 3920: 3914: 3908: 3882: 3876: 3870: 3847: 3844: 3838: 3832: 3826: 3820: 3808: 3802: 3789: 3783: 3777: 3754: 3751: 3748: 3742: 3739: 3719: 3716: 3713: 3707: 3699: 3696: 3692: 3684: 3683:inverse image 3668: 3665: 3662: 3642: 3636: 3633: 3630: 3622: 3603: 3590: 3584: 3578: 3571:to its image 3555: 3542: 3539: 3519: 3513: 3510: 3507: 3499: 3494: 3490: 3486: 3481: 3478: 3475: 3471: 3467: 3463: 3462:right-adjoint 3458: 3454: 3449: 3445: 3440: 3436: 3431: 3428: 3424: 3422:Limit functor 3421: 3418: 3414: 3410: 3406: 3402: 3399: 3395: 3389: 3384: 3380: 3375: 3373: 3370: 3366: 3361: 3359: 3356: 3352: 3348: 3344: 3340: 3336: 3332: 3327: 3323: 3318: 3315: 3312: 3308: 3304: 3300: 3296: 3292: 3291: 3287:) are called 3286: 3270: 3267: 3264: 3255: 3251: 3246: 3242: 3238: 3234: 3230: 3226: 3222: 3218: 3215: 3212: 3208: 3204: 3200: 3184: 3178: 3175: 3172: 3164: 3161:-presheaf on 3160: 3156: 3152: 3148: 3146: 3143: 3128: 3122: 3119: 3116: 3108: 3104: 3100: 3096: 3092: 3090: 3087: 3086: 3082: 3080: 3078: 3077:homomorphisms 3074: 3069: 3067: 3063: 3059: 3054: 3050: 3045: 3041: 3037: 3033: 3029: 3025: 3017: 3013: 3009: 3005: 3001: 2997: 2993: 2990: 2986: 2982: 2978: 2975: 2974: 2973: 2971: 2963: 2961: 2957: 2952: 2948: 2943: 2941: 2937: 2932: 2928: 2924: 2919: 2915: 2911: 2907: 2899: 2897: 2883: 2880: 2865: 2851: 2847: 2837: 2821: 2818: 2804: 2772: 2768: 2765: 2743: 2739: 2720: 2716: 2712: 2709: 2687: 2683: 2674: 2670: 2666: 2663: 2643: 2612: 2591: 2571: 2540: 2519: 2488: 2467: 2447: 2439: 2412: 2380: 2348: 2330: 2326: 2312: 2304: 2288: 2282: 2279: 2276: 2264: 2262: 2260: 2256: 2252: 2248: 2247:contravariant 2244: 2226: 2214: 2209: 2201: 2196: 2167: 2155: 2150: 2142: 2137: 2077: 2072: 2047: 2025: 2021: 1993: 1989: 1983: 1978: 1970: 1966: 1962: 1958: 1927: 1923: 1895: 1891: 1885: 1880: 1872: 1867: 1860: 1857: 1846: 1830: 1825: 1821: 1813: 1794: 1790: 1785: 1781: 1776: 1762: 1746: 1743: 1736: 1717: 1714: 1700: 1699:vector fields 1695: 1693: 1688: 1663: 1656: 1653: 1650: 1630: 1613: 1609: 1606: 1586: 1580: 1577: 1574: 1543: 1535: 1531: 1527: 1522: 1418: 1382: 1381: 1379: 1290: 1242: 1167: 1131: 1130: 1128: 1127: 1126: 1118: 1102: 1096: 1093: 1090: 1070: 1064: 1061: 1058: 1035: 1029: 1026: 1020: 1014: 1011: 1005: 1002: 999: 993: 986: 983: 967: 940: 934: 921: 913: 897: 890: 889: 887: 868: 862: 853: 847: 844: 838: 832: 824: 808: 802: 799: 796: 788: 785: 766: 760: 752: 736: 728: 727: 726: 724: 720: 716: 713: 707: 699: 697: 695: 691: 681: 665: 659: 656: 653: 631: 625: 622: 619: 596: 590: 587: 581: 575: 572: 566: 563: 560: 554: 547: 544: 528: 501: 495: 482: 474: 458: 451: 450: 448: 429: 423: 414: 408: 405: 399: 393: 385: 369: 363: 360: 357: 350: 346: 343: 324: 318: 311:to an object 310: 294: 287: 283: 282: 281: 279: 275: 271: 268: 264: 260: 256: 237: 217: 197: 188: 180: 170: 167: 159: 156:November 2023 149: 145: 139: 136:This article 134: 125: 124: 118: 116: 114: 113:function word 111:context; see 110: 106: 102: 101:Rudolf Carnap 98: 94: 90: 85: 83: 79: 75: 71: 67: 63: 59: 55: 51: 47: 40: 33: 19: 18:Functoriality 6909:Conservative 6886: 6769: 6750:Categorified 6654:n-categories 6605:Key concepts 6443:Direct limit 6426:Coequalizers 6344:Yoneda lemma 6318: 6250:Key concepts 6240:Key concepts 6179:The catsters 6159:package for 6147:-categories. 6144: 6143:The Tale of 6107:the original 6072: 6053: 6016: 5996: 5970: 5957: 5945: 5930:, Springer, 5927: 5906: 5891:, Springer, 5888: 5875: 5863:. Retrieved 5848: 5841: 5829: 5817: 5805: 5797: 5789: 5771: 5762: 5699: 5695: 5690:used to map 5664: 5646: 5615: 5602: 5598: 5594: 5590: 5588: 5572: 5568: 5564: 5560: 5558:is given by 5550: 5543: 5536: 5529: 5525: 5521: 5515: 5507: 5500: 5496: 5487: 5480: 5476: 5470: 5466: 5462: 5457: 5453: 5449: 5443: 5439: 5433: 5429: 5425: 5421: 5406: 5402: 5398: 5394: 5392:is given by 5384: 5377: 5370: 5363: 5355: 5351: 5345: 5337: 5330: 5326: 5317: 5310: 5306: 5300:denotes the 5297: 5292: 5288: 5284: 5279: 5275: 5267: 5263: 5255: 5251: 5237: 5229: 5224: 5220: 5216: 5205: 5197: 5184: 5180: 5173: 5160: 5156: 5152: 5150:The functor 5140: 5136: 5132: 5094: 5076:Lie algebras 5070: 5066: 5062: 5057: 5053: 5048: 5039: 5035: 5027: 5023: 5019: 5016:group action 5011: 5007: 5003: 4999: 4948: 4944: 4939: 4935: 4931: 4927: 4924:by the rule 4919: 4915: 4911: 4901: 4897: 4893: 4888: 4884: 4864:fundamental 4863: 4850: 4846: 4835: 4831: 4814: 4810: 4806: 4799: 4795: 4786: 4782: 4778: 4770: 4753: 4749: 4736: 4725: 4721: 4713: 4706: 4702: 4696: 4692: 4688: 4674: 4670: 4659: 4655: 4649: 4642: 4638: 4629: 4625: 4598:vector space 3623:which sends 3620: 3492: 3488: 3484: 3456: 3452: 3447: 3438: 3434: 3429: 3425:For a fixed 3416: 3412: 3408: 3393: 3387: 3382: 3381:In category 3354: 3350: 3346: 3342: 3338: 3334: 3330: 3325: 3321: 3319:The functor 3310: 3306: 3298: 3294: 3288: 3284: 3253: 3249: 3244: 3240: 3232: 3220: 3210: 3205:is called a 3202: 3198: 3162: 3158: 3154: 3150: 3106: 3102: 3098: 3094: 3070: 3061: 3057: 3052: 3048: 3043: 3039: 3035: 3031: 3027: 3023: 3021: 3015: 3011: 3007: 3003: 2995: 2988: 2984: 2976: 2967: 2955: 2950: 2947:multifunctor 2946: 2944: 2935: 2930: 2926: 2922: 2909: 2905: 2903: 2302: 2301:induces the 2268: 2254: 2250: 2246: 2242: 1696: 1691: 1689: 1529: 1525: 1523: 1520: 1124: 1116: 981: 885: 822: 783: 750: 722: 718: 714: 711: 709: 687: 679: 542: 446: 383: 341: 308: 277: 273: 269: 266: 258: 254: 252: 162: 153: 137: 104: 92: 88: 86: 84:is applied. 53: 43: 6718:-categories 6694:Kan complex 6684:Tricategory 6666:-categories 6556:Subcategory 6314:Exponential 6282:Preadditive 6277:Pre-abelian 6161:Mathematica 6081:AndrΓ© Joyal 5412:Hom functor 5242:free object 5099:linear maps 5085:Lie algebra 4914:) : C( 4905:induces an 3385:, written 1 3363:Endofunctor 3227:, then the 3000:isomorphism 2940:Hom functor 2918:Hom functor 2257:. See also 1845:expressions 694:composition 46:mathematics 6736:3-category 6726:2-category 6699:∞-groupoid 6674:Bicategory 6421:Coproducts 6381:Equalizers 6287:Bicategory 5986:References 5733:Profunctor 5728:Anafunctor 5626:direct sum 5234:free group 4987:dual space 4971:derivative 4967:smooth map 4965:and every 4943:for every 4742:, denoted 4684:continuous 4612:to itself. 4606:linear map 4602:dual space 4481:Note that 3863:. Suppose 3290:presheaves 2964:Properties 1692:cofunctors 704:See also: 263:categories 119:Definition 109:linguistic 87:The words 78:continuous 62:categories 6939:Forgetful 6785:Symmetric 6730:2-functor 6470:Relations 6393:Pullbacks 6165:morphisms 6097:CiteSeerX 6060:EMS Press 6050:"Functor" 5696:morphisms 5692:functions 5115:⊗ 5081:Lie group 4735:based at 4385:↦ 4294:↦ 4206:↦ 4092:↦ 4048:↦ 3714:⊆ 3697:− 3666:⊆ 3640:→ 3634:: 3591:∈ 3543:∈ 3517:→ 3511:: 3498:power set 3355:selection 3268:⊆ 3229:open sets 3182:→ 3176:: 3126:→ 3120:: 2906:bifunctor 2819:∘ 2769:∘ 2736:→ 2713:: 2680:→ 2667:: 2345:→ 2327:: 2286:→ 2280:: 2251:covariant 2243:pullbacks 2206:Λ 2147:Λ 2102:Λ 2069:Λ 2036:Λ 2030:ω 2018:ω 1990:ω 1975:Λ 1959:ω 1932:Λ 1877:Λ 1826:∗ 1786:∗ 1771:Γ 1709:Γ 1660:→ 1654:: 1628:→ 1610:: 1584:→ 1578:: 1530:covariant 1463:→ 1419:∘ 1335:→ 1291:∘ 1200:→ 1168:∘ 1100:→ 1094:: 1068:→ 1062:: 1027:∘ 1003:∘ 860:→ 845:: 806:→ 800:: 663:→ 657:: 629:→ 623:: 588:∘ 564:∘ 421:→ 406:: 367:→ 361:: 97:Aristotle 6985:Functors 6979:Category 6954:Monoidal 6924:Enriched 6919:Diagonal 6899:Additive 6845:Glossary 6825:Category 6799:n-monoid 6752:concepts 6408:Colimits 6376:Products 6329:Morphism 6272:Concrete 6267:Additive 6257:Category 6153:WildCats 6118:Archived 5995:(2009), 5926:(2004), 5887:(1992), 5865:23 April 5796:(1937). 5770:(1971), 5706:See also 5542:) β†’ Hom( 5499: : 5479: : 5376:) β†’ Hom( 5329: : 5309: : 5219: : 5155: : 4896: : 4866:groupoid 4781: : 4767:homotopy 4691: : 4637:, where 4084:, where 3487: : 3357:functor. 3351:constant 3207:presheaf 3083:Examples 2532:. Since 2436:are the 2372:, where 2022:′ 1967:′ 1924:′ 1861:′ 1847:such as 349:morphism 190:Functor 89:category 60:between 6949:Logical 6914:Derived 6904:Adjoint 6887:Functor 6835:Outline 6794:n-group 6759:2-group 6714:Strict 6704:∞-topos 6500:Modules 6438:Pushout 6386:Kernels 6319:Functor 6262:Abelian 6070:at the 6068:functor 6062:, 2001 5678:Functor 5671:Haskell 5638:inverse 5296:(where 5232:to the 5043:, is a 5030:to the 4969:to its 4961:to its 3936:. Then 3681:to its 3464:to the 3235:form a 3089:Diagram 3006:, then 1761:1-forms 267:functor 142:Please 105:functor 93:functor 58:mapping 54:functor 6964:Smooth 6781:Traced 6764:2-ring 6494:Fields 6480:Groups 6475:Magmas 6363:Limits 6099:  6085:CatLab 6032:  6003:  5934:  5895:  5856:  5778:  5680:where 5673:has a 5634:direct 5624:, the 5410:. See 4995:Every 4989:above. 4918:) β†’ C( 4351:  4266:  3442:has a 3073:monoid 2998:is an 2970:axioms 286:object 6934:Exact 6889:types 6775:-ring 6662:Weak 6646:Topos 6490:Rings 6155:is a 5754:Notes 5686:is a 5675:class 5474:. If 5274:from 5166:group 5069:. If 4997:group 4947:in C( 4828:from 4763:group 4700:with 4610:field 3770:then 3444:limit 3391:or id 3239:Open( 3223:is a 3056:from 2972:are: 2702:with 1810:of a 1733:of a 717:from 272:from 107:in a 56:is a 6465:Sets 6066:see 6030:ISBN 6001:ISBN 5974:See 5932:ISBN 5893:ISBN 5867:2016 5854:ISBN 5776:ISBN 5700:Hask 5683:fmap 5636:and 5628:and 5593:and 5589:Let 5520:Hom( 5494:and 5438:Hom( 5362:Hom( 5350:Hom( 5324:and 5190:ring 5036:Vect 4934:) = 4712:) = 4686:map 4600:its 3901:and 3403:The 3301:the 3157:, a 3153:and 3097:and 3034:and 2460:and 2404:and 2008:for 1910:for 1083:and 692:and 646:and 265:. A 257:and 253:Let 230:and 99:and 91:and 52:, a 6309:End 6299:CCC 6129:: " 6075:Lab 6022:doi 5698:on 5601:to 5471:Set 5458:Set 5452:to 5278:to 5258:of 5225:Grp 5221:Set 5198:Rng 5181:Rng 5161:Set 5157:Grp 5093:If 5047:of 5018:of 5012:Set 5010:to 4843:to 4765:of 4667:to 4526:on 3985:of 3493:Set 3489:Set 3353:or 3337:in 3293:on 3231:in 3219:If 3209:on 3199:Set 3105:in 3060:to 3042:to 3030:to 3002:in 2994:if 2983:in 2958:= 2 2936:two 2931:Set 2796:or 2440:to 1950:or 1115:in 980:in 884:in 821:in 782:in 749:in 721:to 678:in 541:in 445:in 382:in 340:in 307:in 276:to 261:be 146:to 44:In 6981:: 6787:) 6783:)( 6171:, 6095:. 6083:, 6058:, 6052:, 6028:, 5922:; 5918:; 5914:; 5883:; 5651:. 5571:∘ 5567:∘ 5563:↦ 5549:, 5535:, 5524:, 5506:β†’ 5486:β†’ 5469:β†’ 5465:Γ— 5442:, 5428:, 5405:∘ 5401:∘ 5397:↦ 5383:, 5369:, 5360:: 5354:, 5346:Ab 5336:β†’ 5316:β†’ 5298:Ab 5293:Ab 5291:β†’ 5289:Ab 5287:Γ— 5285:Ab 5266:, 5254:, 5223:β†’ 5206:Ab 5185:Ab 5183:β†’ 5159:β†’ 5139:β†’ 5135:Γ— 5056:β†’ 5034:, 4951:). 4938:∘ 4930:)( 4926:C( 4910:C( 4900:β†’ 4849:, 4845:Ο€( 4834:, 4830:Ο€( 4785:β†’ 4752:, 4695:β†’ 4673:, 4658:, 4628:, 3491:β†’ 3455:β†’ 3437:β†’ 3324:β†’ 3252:β†’ 3068:. 3051:∘ 2960:. 2945:A 2929:β†’ 2925:Γ— 2904:A 2896:. 2838:, 2604:, 2261:. 1694:. 115:. 6879:e 6872:t 6865:v 6779:( 6772:n 6770:E 6732:) 6728:( 6716:n 6680:) 6676:( 6664:n 6506:) 6502:( 6496:) 6492:( 6220:e 6213:t 6206:v 6175:. 6145:n 6073:n 6024:: 6010:. 5869:. 5694:( 5603:D 5599:C 5595:D 5591:C 5573:f 5569:Ο† 5565:g 5561:Ο† 5556:) 5554:2 5551:Y 5547:1 5544:X 5540:1 5537:Y 5533:2 5530:X 5526:g 5522:f 5516:C 5511:2 5508:Y 5504:1 5501:Y 5497:g 5491:2 5488:X 5484:1 5481:X 5477:f 5467:C 5463:C 5454:Y 5450:X 5446:) 5444:Y 5440:X 5434:C 5430:Y 5426:X 5422:C 5414:. 5407:f 5403:Ο† 5399:g 5395:Ο† 5390:) 5388:2 5385:B 5381:1 5378:A 5374:1 5371:B 5367:2 5364:A 5358:) 5356:g 5352:f 5341:2 5338:B 5334:1 5331:B 5327:g 5321:2 5318:A 5314:1 5311:A 5307:f 5280:B 5276:A 5268:B 5264:A 5256:B 5252:A 5244:. 5238:X 5230:X 5217:F 5200:( 5153:U 5141:C 5137:C 5133:C 5118:W 5112:V 5095:C 5071:C 5067:C 5063:G 5058:C 5054:G 5049:G 5040:K 5028:G 5024:G 5020:G 5008:G 5004:G 5000:G 4949:Y 4945:Ο† 4940:f 4936:Ο† 4932:Ο† 4928:f 4922:) 4920:X 4916:Y 4912:f 4902:Y 4898:X 4894:f 4889:X 4885:X 4856:) 4854:0 4851:y 4847:Y 4841:) 4839:0 4836:x 4832:X 4818:0 4815:y 4811:Y 4807:f 4803:0 4800:x 4796:X 4787:Y 4783:X 4779:f 4774:0 4771:x 4759:) 4757:0 4754:x 4750:X 4748:( 4746:1 4744:Ο€ 4740:0 4737:x 4729:0 4726:x 4722:X 4717:0 4714:y 4710:0 4707:x 4705:( 4703:f 4697:Y 4693:X 4689:f 4680:) 4678:0 4675:y 4671:Y 4669:( 4665:) 4663:0 4660:x 4656:X 4654:( 4650:X 4646:0 4643:x 4639:X 4635:) 4633:0 4630:x 4626:X 4624:( 4574:X 4554:f 4534:X 4510:) 4507:} 4504:1 4501:, 4498:0 4495:{ 4492:( 4489:f 4469:. 4466:} 4463:X 4460:, 4457:} 4454:{ 4451:{ 4448:= 4445:} 4442:) 4439:1 4436:( 4433:f 4430:, 4427:) 4424:0 4421:( 4418:f 4415:{ 4412:= 4409:) 4406:} 4403:1 4400:, 4397:0 4394:{ 4391:( 4388:f 4382:} 4379:1 4376:, 4373:0 4370:{ 4348:, 4345:} 4342:X 4339:{ 4336:= 4333:} 4330:) 4327:1 4324:( 4321:f 4318:{ 4315:= 4312:) 4309:} 4306:1 4303:{ 4300:( 4297:f 4291:} 4288:1 4285:{ 4263:, 4260:} 4257:} 4254:{ 4251:{ 4248:= 4245:} 4242:) 4239:0 4236:( 4233:f 4230:{ 4227:= 4224:) 4221:} 4218:0 4215:{ 4212:( 4209:f 4203:} 4200:0 4197:{ 4177:} 4174:{ 4171:= 4168:) 4165:} 4162:{ 4159:( 4156:) 4153:) 4150:f 4147:( 4144:F 4141:( 4121:) 4118:f 4115:( 4112:F 4072:} 4069:{ 4066:= 4063:) 4060:} 4057:{ 4054:( 4051:f 4045:} 4042:{ 4022:) 4019:U 4016:( 4013:f 3993:X 3973:U 3953:) 3950:f 3947:( 3944:F 3924:X 3921:= 3918:) 3915:1 3912:( 3909:f 3889:} 3886:{ 3883:= 3880:) 3877:0 3874:( 3871:f 3851:} 3848:X 3845:, 3842:} 3839:1 3836:{ 3833:, 3830:} 3827:0 3824:{ 3821:, 3818:} 3815:{ 3812:{ 3809:= 3806:) 3803:X 3800:( 3795:P 3790:= 3787:) 3784:X 3781:( 3778:F 3758:} 3755:1 3752:, 3749:0 3746:{ 3743:= 3740:X 3720:. 3717:X 3711:) 3708:V 3705:( 3700:1 3693:f 3669:Y 3663:V 3643:Y 3637:X 3631:f 3607:) 3604:Y 3601:( 3596:P 3588:) 3585:U 3582:( 3579:f 3559:) 3556:X 3553:( 3548:P 3540:U 3520:Y 3514:X 3508:f 3485:P 3457:C 3453:C 3448:C 3439:C 3435:J 3430:J 3417:D 3413:D 3409:D 3394:C 3388:C 3383:C 3371:. 3347:X 3343:C 3339:D 3335:X 3331:C 3326:D 3322:C 3313:. 3311:X 3307:U 3299:U 3295:X 3285:X 3271:V 3265:U 3254:V 3250:U 3245:X 3241:X 3233:X 3221:X 3213:. 3211:C 3203:D 3185:J 3179:C 3173:D 3163:C 3159:J 3155:J 3151:C 3141:. 3129:C 3123:J 3117:D 3107:C 3103:J 3099:J 3095:C 3062:C 3058:A 3053:F 3049:G 3044:C 3040:B 3036:G 3032:B 3028:A 3024:F 3018:. 3016:D 3012:f 3010:( 3008:F 3004:C 2996:f 2991:; 2989:D 2985:C 2977:F 2956:n 2951:n 2927:C 2923:C 2884:F 2881:= 2875:p 2872:o 2866:) 2860:p 2857:o 2852:F 2848:( 2822:F 2813:p 2810:o 2805:G 2781:p 2778:o 2773:F 2766:G 2744:2 2740:C 2730:p 2727:o 2721:1 2717:C 2710:G 2688:1 2684:C 2675:0 2671:C 2664:F 2644:F 2621:p 2618:o 2613:F 2592:D 2572:C 2549:p 2546:o 2541:C 2520:F 2497:p 2494:o 2489:F 2468:D 2448:C 2421:p 2418:o 2413:D 2389:p 2386:o 2381:C 2357:p 2354:o 2349:D 2339:p 2336:o 2331:C 2321:p 2318:o 2313:F 2289:D 2283:C 2277:F 2227:j 2222:e 2215:i 2210:j 2202:= 2197:i 2192:e 2168:j 2163:e 2156:j 2151:i 2143:= 2138:i 2133:e 2108:T 2078:j 2073:i 2048:. 2042:T 2026:= 1994:j 1984:j 1979:i 1971:= 1963:i 1937:x 1928:= 1920:x 1896:j 1892:x 1886:i 1881:j 1873:= 1868:i 1858:x 1831:M 1822:T 1795:) 1791:M 1782:T 1777:( 1747:M 1744:T 1721:) 1718:M 1715:T 1712:( 1672:p 1669:o 1664:D 1657:C 1651:F 1631:D 1622:p 1619:o 1614:C 1607:F 1587:D 1581:C 1575:F 1552:p 1549:o 1544:C 1503:t 1500:n 1497:a 1494:i 1491:r 1488:a 1485:v 1482:a 1479:r 1476:t 1473:n 1470:o 1467:C 1459:t 1456:n 1453:a 1450:i 1447:r 1444:a 1441:v 1438:a 1435:r 1432:t 1429:n 1426:o 1423:C 1415:t 1412:n 1409:a 1406:i 1403:r 1400:a 1397:v 1394:o 1391:C 1363:t 1360:n 1357:a 1354:i 1351:r 1348:a 1345:v 1342:o 1339:C 1331:t 1328:n 1325:a 1322:i 1319:r 1316:a 1313:v 1310:a 1307:r 1304:t 1301:n 1298:o 1295:C 1287:t 1284:n 1281:a 1278:i 1275:r 1272:a 1269:v 1266:a 1263:r 1260:t 1257:n 1254:o 1251:C 1228:t 1225:n 1222:a 1219:i 1216:r 1213:a 1210:v 1207:o 1204:C 1196:t 1193:n 1190:a 1187:i 1184:r 1181:a 1178:v 1175:o 1172:C 1164:t 1161:n 1158:a 1155:i 1152:r 1149:a 1146:v 1143:o 1140:C 1119:. 1117:C 1103:Z 1097:Y 1091:g 1071:Y 1065:X 1059:f 1039:) 1036:g 1033:( 1030:F 1024:) 1021:f 1018:( 1015:F 1012:= 1009:) 1006:f 1000:g 997:( 994:F 984:, 982:C 968:X 944:) 941:X 938:( 935:F 930:d 927:i 922:= 919:) 914:X 909:d 906:i 901:( 898:F 886:D 872:) 869:X 866:( 863:F 857:) 854:Y 851:( 848:F 842:) 839:f 836:( 833:F 823:C 809:Y 803:X 797:f 786:, 784:D 770:) 767:X 764:( 761:F 751:C 737:X 723:D 719:C 715:F 682:. 680:C 666:Z 660:Y 654:g 632:Y 626:X 620:f 600:) 597:f 594:( 591:F 585:) 582:g 579:( 576:F 573:= 570:) 567:f 561:g 558:( 555:F 545:, 543:C 529:X 505:) 502:X 499:( 496:F 491:d 488:i 483:= 480:) 475:X 470:d 467:i 462:( 459:F 447:D 433:) 430:Y 427:( 424:F 418:) 415:X 412:( 409:F 403:) 400:f 397:( 394:F 384:C 370:Y 364:X 358:f 344:, 342:D 328:) 325:X 322:( 319:F 309:C 295:X 278:D 274:C 270:F 259:D 255:C 238:f 218:g 198:F 169:) 163:( 158:) 154:( 140:. 41:. 34:. 20:)

Index

Functoriality
Functor (disambiguation)
Langlands program Β§ Functoriality
mathematics
category theory
mapping
categories
algebraic topology
fundamental group
topological spaces
continuous
category theory
Aristotle
Rudolf Carnap
linguistic
function word
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categories
object
morphism
identity morphisms
composition
Covariance and contravariance (computer science)
opposite category
vector fields
tangent bundle

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