转向
发表于 2025-3-23 10:18:41
http://reply.papertrans.cn/16/1552/155124/155124_11.png
Euphonious
发表于 2025-3-23 17:23:22
The Fundamental Group,path components. The functor to be constructed in this chapter takes values in ., the category of (not necessarily abelian) groups. The basic idea is that one can “multiply” two paths . and . if . ends where . begins.
萤火虫
发表于 2025-3-23 21:00:44
http://reply.papertrans.cn/16/1552/155124/155124_13.png
Influx
发表于 2025-3-24 01:51:12
Homotopy Groups,s from S. into .. It is thus quite natural to consider (pointed) maps of . into a space .; their homotopy classes will be elements of the . .(., x.). This chapter gives the basic properties of the homotopy groups; in particular, it will be seen that they satisfy every Eilenberg-Steenrod axiom save excision.
救护车
发表于 2025-3-24 06:26:47
http://reply.papertrans.cn/16/1552/155124/155124_15.png
引水渠
发表于 2025-3-24 08:49:27
http://reply.papertrans.cn/16/1552/155124/155124_16.png
锯齿状
发表于 2025-3-24 14:33:57
Jan van Deth,Hans Rattinger,Edeltraud Rollerhether a union of .-simplexes in a space . that “ought” to be the boundary of some union of (. + 1)-simplexes in X actually is such a boundary. Consider the case . = 0; a 0-simplex in . is a point. Given two points x., x. ∈ ., they “ought” to be the endpoints of a 1-simplex; that is, there ought to
Interdict
发表于 2025-3-24 16:11:01
http://reply.papertrans.cn/16/1552/155124/155124_18.png
吹牛需要艺术
发表于 2025-3-24 19:08:22
https://doi.org/10.1007/978-3-658-10138-1few cases in which we could compute these groups. At this point, however, we would have difficulty computing the homology groups of a space as simple as the torus . = . x .; indeed .(.) is uncountable for every . ≥ 0, so it is conceivable that .(.) is uncountable for every . (we shall soon see that
中国纪念碑
发表于 2025-3-25 01:29:58
Ellen Banzhaf,Sigrun Kabisch,Dieter Rinkor it will allow us to compare different functors; in particular, it will make precise the question whether two functors are isomorphic. The notion of an adjoint pair of functors, though intimately involved with naturality, will not be discussed until Chapter 11, where it will be used.