I have been studying Freyd's algebraic theory of the reals in the past week. I have problems understanding his linear representation theorem (Theorem 8.1) that every scale can be embedded in a prod...| Mathematics Stack Exchange
A covering map $p:C\to X$ is finite when for each $x\in X$ we have $|p^{-1}(x)|<\infty.$ I have to prove that such a covering map has to be closed. I'm having trouble with it. When $p$ is a co...| Mathematics Stack Exchange
The Orbit-Stabilizer says that, given a group $G$ which acts on a set $X$, then there exists a bijection between the orbit of an element $x\in X$ and the set of left cosets of the stabilizer group ...| Mathematics Stack Exchange
Having nothing better to do, I tried multiplying different (but mostly small) permutation matrices with themselves, and so far at some point I'd always run into an identity matrix. Was I just "luc...| Mathematics Stack Exchange
For all $a, m, n \in \mathbb{Z}^+$, $$\gcd(a^n - 1, a^m - 1) = a^{\gcd(n, m)} - 1$$| Mathematics Stack Exchange
I've looked up several related questions, but they do not answer what I am looking for. Please give link if this is a duplicate. What I eventually want to know is why $$\lim_{n\to\infty}\left(1+\| Mathematics Stack Exchange
One of my Fellows asked me whether total induction is applicable to real numbers, too ( or at least all real numbers ≥ 0) . We only used that for natural numbers so far. Of course you have to change| Mathematics Stack Exchange
