
What is infinity divided by infinity? - Mathematics Stack Exchange
Aug 11, 2012 · I know that $\\infty/\\infty$ is not generally defined. However, if we have 2 equal infinities divided by each other, would it be 1? if we have an infinity divided by another half-as …
general topology - Infinite compact subset of $\mathbb {Q ...
Nov 6, 2013 · In fact, more is known: Theorem: Every (Hausdorff) countable compact is homeomorphic to a subspace of Q Q. Essentially, it is a consequence of Sierpinski …
Associativity of infinite matrix product. - Mathematics Stack …
A treatise on this can be found in On the associativity of infinite matrix multiplication. However, if x x and v v are infinite vectors, and A A is a semi-infinite matrix, then Does the product x⊺Au x ⊺ …
Isomorphism between infinite dimensional vector spaces
Sep 11, 2011 · the set of all infinitely long sequences of real numbers The first is a finite-dimensional vector space. The next three are infinite-dimensional vector spaces. They're not …
Infinite intersection of open sets - Mathematics Stack Exchange
Oct 2, 2015 · Similarly, to disprove infinite intersection of open sets is open, it is enough to give a particular collection of open sets such that intersection is not open.
real analysis - Prove that an infinite sigma algebra contains an ...
Jan 2, 2015 · I am wondering if we just showed that any infinite set of sets contains an infinite restriction. So that the sigma algebra component isn't needed for the next iteration.
Uncountable vs Countable Infinity - Mathematics Stack Exchange
Nov 5, 2015 · My friend and I were discussing infinity and stuff about it and ran into some disagreements regarding countable and uncountable infinity. As far as I understand, the list of …
discrete mathematics - Countably Infinite, Uncountable or Finite ...
Dec 5, 2015 · I am having trouble with the following terms: countably infinite, uncountable, and finite. In addition, for the following problems I need to select which category they fall into. $1)$ …
Partitioning an infinite set - Mathematics Stack Exchange
Dec 1, 2010 · Can you partition an infinite set, into an infinite number of infinite sets?
permutations - Normal subgroups of infinite symmetric group ...
Sep 16, 2017 · Here "infinite grade" refers to infiniteness of the complement. He proves (§110, p108) that the only subgroup of the group of permutations of I I that is infinitely transitive of …