trying to prove the characteristic function commutes with limsup
87918
liminf and limsup with characteristic (indicator) function
130916
Proving the identity functions is continuous iff $\tau_1\supseteq\tau_2$
11539
Prove $\limsup\limits_{n \to \infty} (a_n+b_n) \le \limsup\limits_{n \to \infty} a_n + \limsup\limits_{n \to \infty} b_n$
91947
Proof of $ f:I_n \rightarrow I_m \Rightarrow n = m$
66481
Convergence of characteristic functions to $1$ on a neighborhood of $0$ and weak convergence
51302
Show that the operator norm is submultiplicative
96919
Characteristic equation of a recurrence relation
48291
Proof that $\mathrm{ker}(f^*) = \mathrm{im}(f)^{\perp} $
10859
Prove $\sup(f+g) \le \sup f + \sup g$
137890
Diagonalizable Operators and characteristic polynomials
75855
Show that $\det{(A + sxy^*)}$ is linear in $s$
17779
Proving the Limit of a Sequence of without the Dominated Convergence Theorem
13253
Prove $f(S \cup T) = f(S) \cup f(T)$
116811
Proofs with limit superior and limit inferior: $\liminf a_n \leq \limsup a_n$
87239
Prove functions defined by sup and inf are continuous
24126
When functions commute under composition
59872
How to prove $\inf(S)=-\sup(-S)$?