What do finite, infinite, countable, not countable, countably infinite mean? [duplicate] Ask Question Asked 13 years ago Modified 13 years ago

2023年5月11日 · Can you give me an example of infinite field of characteristic $p\\neq0$? Thanks.

Why is the infinite sphere contractible? I know a proof from Hatcher p. 88, but I don't understand how this is possible. I really understand the statement and the proof, but in my imagination this...

Meaning of Infinite Union/Intersection of sets Ask Question Asked 8 years, 5 months ago Modified 3 years, 11 months ago

The dual space of an infinite-dimensional vector space is always strictly larger than the original space, so no to both questions. This was discussed on MO but I can't find the thread.

2020年6月6日 · The reason being, especially in the non-standard analysis case, that "infinite number" is sort of awkward and can make people think about $\infty$ or infinite cardinals …

57 Why are box topology and product topology different on infinite products of topological spaces ? I'm reading Munkres's topology. He mentioned that fact but I can't see why it's true that they …

The infinite manifold of two or three dimensions, the mathematical beings which depend on a number of variables greater even than three, any number in fact, still have no greater power …

De Morgan's law on infinite unions and intersections Ask Question Asked 14 years, 3 months ago Modified 4 years, 8 months ago

2015年1月26日 · Linear Transformations on Infinite Dimensional Vector Spaces Ask Question Asked 10 years, 6 months ago Modified 10 years, 6 months ago