chain A s.t. $|X|<|A|\leq |P(X)|$
109054
Given an infinite set of cardinality $X$, is there a chain in $\mathcal P(X)$ of the same cardinalty of $\mathcal P(X)$?
36485
$H_n(X,A) \not \approx \tilde{H}_n(X/A)$
49240
$\forall x,y \in \mathbb{R}:\vert\cos x- \cos y\vert\leq\vert x-y\vert$
93165
A projection satisfying $\| Px \| \leq \|x\|$ for all $x$ is an orthogonal projection
150385
The use of the Axiom of Choice in this proof of the sequence lemma
37183
Show that the set of all $x$ such that $x \in P$ and $x \notin Q$ exists
41477
Prove $f(S \cap T) \subseteq f(S) \cap f(T)$
155974
Show $||Tx||_2 \leq ||(v_n)||_2 \cdot ||x||_{\infty}$
76863
How to show $ \sup \inf g(x,y) \leq \inf \sup g(x,y)$?
81618
Prove $||a|-|b| | \leq |a-b|$
106767
$|p(z)| \leq M$ for $|z| \leq 1$ Show that $|p(z)| \leq M|z|^n$ for $|z| \geq 1$
46760
To show that $P(|X-Y| \leq 2) \leq 3P(|X-Y| \leq 1)$
126165
Prove $|\arctan x - \arctan y|\leq |x-y|$
42150
Prove that $\forall x \neg P(x) \iff \neg \exists x P(x)$
64075
Prove that a set of connectives is inadequate
4498
Proof that $\|fx\| \leq \|f\|\cdot\|x\|$
3896
A closed set in $(A, \mathcal T_A)$ that is not closed in $(X, \mathcal T)$