
Thm. Every vector space has a basis. (even in the case of infinite dimension) proof) Let V be a vector space other than {0}. Pick a vector x≠0 from V. Consider the set X={S⊆V|x∈S,S is linearly independent}. Then (X,⊆) is an ordered set. Obviously X is nonempty because {x}∈X. By Hausdorff maximal principle (see below), X has a maximal..
mathe
2024. 8. 10. 03:02