New posts in elementary-set-theory

$\wedge,\cap$ and $\vee,\cup$ between Logic and Set Theory always interchangeable?

A set which is not isomorphic to it's proper subset is finite

Meaning of pullback

Are these open sets?

a totally ordered set with small well ordered set has to be small?

How is Russell’s Paradox equal to the universal set?

Subtraction of elements in sets

How do you prove the trichotomy law for cardinal numbers?

Cardinality as "size of a set" [closed]

Question about members in sets

Why does the Axiom of Selection solve Russell's Paradox in Set Theory?

Examples of bijections from $\mathbb Z\to\mathbb Z$ such that their sum is a bijection?

Number of nodes in an infinite binary tree

Bolzano-Weierstrass for sequences of sets

Meaning of "$\exists$" in "$\{y \in Y : \exists x \in X \text{ such that }f(x) = y\}$"

What are your favorite proofs using mathematical induction? [closed]

Notation for unordered product of sets

Is this Partition affirmation correct? [closed]

supremum, infimum, max and min - assistance understanding the difference

The number of families of subsets of $\{1,2,...,n\}$ whose union is not the whole set.