$A \subset B$ and $A \subseteq B$, what is the difference?
47562
Confusion in symbol of subset.
3072
If the empty set is a subset of every set, why isn't $\{\emptyset,\{a\}\}=\{\{a\}\}$?
153823
$|\text{rank}A-\text{rank}B|\leq \text{rank}(A+B)$
40604
Is this proof correct for : Does $F(A)\cap F(B)\subseteq F(A\cap B) $ for all functions $F$?
86926
Why isn't this a well ordering of $\{A\subseteq\mathbb N\mid A\text{ is infinite}\}$?
137707
How to prove that $(A\cup B) \cap C \subseteq A\cup (B\cap C)$
147237
If $A$ and $B$ are compact subsets of $\mathbb R$, then so is $\frac{A}B$.
85099
How many subsets of $\mathbb{N}$ have the same cardinality as $\mathbb{N}$?
130297
$A$ be a subset of $[0,1]$ with non-empty interior ; then is it true that $\mathbb Q+A=\mathbb R$?
67709
Stuck with proof for $\forall A\forall B(\mathcal{P}(A)\cup\mathcal{P}(B)=\mathcal{P}(A\cup B)\rightarrow A\subseteq B \vee B\subseteq A)$
72256
Prove there exists two sub-sets of indices $I,J\subseteq [2n]$ such that $\sum_{i\in I}a_i=\sum_{j\in J}b_j$
16056
Is empty set element of every set if it is subset of every set?
110485
Nested sequence of non-empty compact subsets - intersection differs from empty set
135694
Proving $\kappa^{\lambda} = |\{X: X \subseteq \kappa, |X|=\lambda\}|$
106564
Suppose $A,B,C$ are sets. Prove that $A\mathbin\triangle B\subseteq C \iff A\cup C=B\cup C$.
79367
Understanding the difference between two theorems related to $|G\,:\,K|=|H\,:\,K|\cdot|G\,:\,H|$.
96845
Question: Compare the cardinality between the sets $\Bbb R$ and $\Bbb N^{\Bbb N}$