Equal supremes in the open right half plane
9748
Maximum modulus principle for an unbounded function in the half right plane
62936
Proving equivalencies of two versions of the Axiom of Choice
141101
Russia (2000) contest:Prove the existence of a pair of rows and columns with intersections differently coloured
123242
Half exact functor which is neither right exact nor left exact
132595
$\sup_{0 \leq M \leq I_{\mathcal{H}_1}} \frac{\operatorname{Tr}[\rho M]}{\operatorname{Tr}[\sigma M]}$ satisfies Data Processing Inequality
115597
Almost universal class
12291
Two envelope problem revisited
121593
Symmetric and exterior power of representation
56512
Divisibility is transitive: $\ a\mid b\mid c\,\Rightarrow\ a\mid c$
132287
Axiom of Choice and Right Inverse
132532
Things around $(\forall x)(\Psi \Rightarrow \Phi) \Leftrightarrow ((\exists z)\Psi) \Rightarrow \Phi)$
158727
Leg bisectors in a trapezoid and angle equality
139743
Necessary condition for have same rank
131475
Example of the equality of an inequality
71497
An inequality from Littlewood's Miscellany
41044
Equivalence of $a \rightarrow b$ and $\lnot a \vee b$
111057
On the position of multiple sub and superindices