Question at the end of the chapter on Functions in Halmos's naive set theory
3101
Meaning of a set in the exponent
12436
The cardinality of the set of all finite subsets of an infinite set
22804
Interpretation of limsup-liminf of sets
48804
Enumeration of rationals from Stein-Shakarchi's Real Analysis (Chapter 1, Exercise 24)
63701
An example of a regular function over an open set
40121
Asymptotes of function
155063
Is Cl(f(A)) a subset of f(Cl(A))?
141299
Alternative set theories
40604
Is this proof correct for : Does $F(A)\cap F(B)\subseteq F(A\cap B) $ for all functions $F$?
45878
Elementary Set Theory: Ordinals, Well Orderings and Isomorphisms
109173
Why the Sets defined in the Cumulative Hierarchy transitive?
16225
Set-theoretical definition of function evaluation
63146
Proof of properties of injective and surjective functions.
89712
For every set $A$, the empty set is a subset of $A$. The empty set is a set. Therefore, the empty set has a cardinality $\geq 1\ldots$
144899
Do We Need the Axiom of Choice for Finite Sets?
48765
Let $S$ and $T$ be finite non-empty sets such that $|S| = |T|$. Show that the function $f : S\to T$ is onto if and only if it is one-to-one.
25553
elementary set theory (cartesian product and symmetric difference proof)