Example of infinite field of characteristic $p\neq 0$
May 11, 2023 · Can you give me an example of infinite field of characteristic $p\\neq0$? Thanks.
Prove that the union of countably many countable sets is countable.
Dec 12, 2013 · I am doing some homework exercises and stumbled upon this question. I don't know where to start. Prove that the union of countably many countable sets is countable. Just …
What is the difference between "infinite" and "transfinite"?
Jun 6, 2020 · 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 …
elementary set theory - What do finite, infinite, countable, not ...
What do finite, infinite, countable, not countable, countably infinite mean? [duplicate] Ask Question Asked 13 years, 2 months ago Modified 13 years, 2 months ago
general topology - Why is the infinite sphere contractible ...
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...
real analysis - Meaning of Infinite Union/Intersection of sets ...
Meaning of Infinite Union/Intersection of sets Ask Question Asked 8 years, 8 months ago Modified 4 years, 1 month ago
An infinite union of closed sets is a closed set?
Apr 24, 2013 · An infinite union of closed sets is a closed set? Ask Question Asked 12 years, 6 months ago Modified 9 months ago
Infinite-dimensional manifolds: Fréchet, Banach and Hilbert …
Jul 15, 2022 · Essentially, it is sought that these manifolds with infinite dimension are homeomorphic, as these topological spaces, to vector spaces of infinite dimension, and this …
Why is tangent infinite sometimes? - Mathematics Stack Exchange
Sep 5, 2016 · The math textbook says it is because when cosine is 0 tangent becomes infinite. The intuition I have is that when one of adjacent or opposite is 0, then tangent is infinite. But …
If $S$ is an infinite $\sigma$ algebra on $X$ then $S$ is not …
6 Show that if a $\sigma$-algebra is infinite, that it contains a countably infinite collection of disjoint subsets. An immediate consequence is that the $\sigma$-algebra is uncountable.