23/12/22 06:28:27.08 iJJua0Zv.net
>>715 ID:ABgxLQki
>なお、下記を再録しておきますね
Manifolds in dimension 4 and above cannot be effectively classified: given two n-manifolds (n≥ 4) presented as CW complexes or handlebodies, there is no algorithm for determining if they are isomorphic (homeomorphic, diffeomorphic).
This is due to the unsolvability of the word problem for groups, or more precisely, the triviality problem (given a finite presentation for a group, is it the trivial group?).
Any finite presentation of a group can be realized as a 2-complex, and can be realized as the 2-skeleton of a 4-manifold (or higher).
Thus one cannot even compute the fundamental group of a given high-dimensional manifold, much less a classification.
>>716 ID:QAjEA2yI
>自分で検索した文章の意味もわかってない
>>717 ID:waV4YpI2
>引用だけして理解もしてないのは数学徒とは言えない
>>718 ID:R0bvGUBP
>相手が言ってる事とそっくり同じ内容の文章を
>引っ張ってくるってどういう頭してんだか
ナニワヤンキー＆ミーハー君は中卒だから
「語の問題」なんて知らんし一生理解できないんだよ