Does $dist(x, \partial A) \leq dist(x, \partial B)$ if $x \in A \subset B$?
93157
If $A \subseteq B$, does $\mbox{dist}(x,\partial A) \le \mbox{dist}(x, \partial B)$ hold for all $x \in A$
141318
$\subset$ vs $\subseteq$ when *not* referring to strict inclusion
70278
$A\subseteq B\to C\setminus B\subseteq C\setminus A\,$ -- how to prove this?
107215
Is $\emptyset \in \emptyset$ or $\emptyset \subseteq \emptyset$?
43462
Disprove $\mathcal{P}(A\Delta B) \setminus \{\emptyset\} = \mathcal{P}(A) \Delta\mathcal{P}(B) $. Is my proof good?
64320
Prove that if $0<a<Pr(A)$ then there exists $B\subset A$ such that $Pr(B)=a$
41099
If $A \subseteq C$ and $B \subseteq D$ then $A \times B \subseteq C \times D$
122271
A subset of a transitive set is transitive
16550
Is $ d(X) \le s(X)? $
139537
Show that $x\subseteq y \Leftrightarrow \mathcal{P}(x)\subseteq\mathcal{P}(y)$.
134770
For sets $A,B$, $A \cap (B \setminus A) \subseteq \varnothing$
20040
shorter proof of generalized mediant inequality?
155929
Let $A, B$ be sets. Show that $\mathcal P(A ∩ B) = \mathcal P(A) ∩ \mathcal P(B)$.
31846
Does $\neg(x > y)$ imply that $y \geq x$?
122326
Proving $|P(A\cap B)-P(A)P(B)|\leq \frac{1}4$
33543
is "y1 < x < y2" an inequality or inequalities?
78463
Prove that $\sup \{-x \mid x \in A\} = -\inf\{x\mid x \in A\}$