proof that inf(-A)=-sup(A)
67892
Infinum & Supremum: An Analysis on Relatedness
45219
Proving that $C$ is a subset of $f^{-1}[f(C)]$
32929
Questions about proving $\lnot \lnot a = a$
88278
Show $S = f^{-1}(f(S))$ for all subsets $S$ iff $f$ is injective
87239
Prove functions defined by sup and inf are continuous
147627
Relation between condition numbers $\kappa(A^T A)$ and $\kappa(A)$
91947
Proof of $ f:I_n \rightarrow I_m \Rightarrow n = m$
137511
Trying to show that $\sup \{b^p:p\in Q,\;0<p<x\} = \inf\{b^q:q\in Q,\;x<q\}$
149664
Norm is sup of inner products (proof).
84301
Showing that some Function on the Unit Disc is injective
97772
An example of a function which satisfies $\sup_{y}\inf_{x}f(x,y)<\inf_{x}\sup_{y}f(x,y)$
68449
$\operatorname{Supp}(M)=V(\operatorname{Ann}M)$ if $M$ is finitely generated
13696
Proving $\limsup\frac 1 {a_n}=\frac 1 {\liminf a_n}$ and $\limsup a_n\cdot \limsup \frac 1 {a_n} \ge 1$
158862
Show that $a(-1) = (-1)a = -a $.
55018
Prove that $A^*A + I$ is invertible
98855
Prove $aba^{-1}b^{-1}\in{N}$ for all $a,b$
136789
How to prove $a \lt b$ for all $a \in A, b \in B$ implies $\sup A \leq \inf B$?