Is ZFC not foundation of mathematics?
58474
When we say, "ZFC can found most of mathematics," what do we really mean?
23837
Why is $\mathbb{R}/{\sim}$ not first countable at $[0]$, where $x \sim y \Leftrightarrow x = y\text{ or }x,y \in \mathbb{Z}$?
34674
Does the proof of Bolzano-Weierstrass theorem require axiom of choice?
42095
Existence in ZF of a set with countable power set
111723
Can it be proven in $\sf ZF^{\neg\infty}$ that the sets $x_n=\{x_{n+1}\}$ do not exist?
143138
All models of $\mathsf{ZFC}$ between $V$ and $V[G]$ are generic extensions of $V$
157187
Why $\omega+1$ and $\omega^2$ are not cardinal numbers?
149926
ZFC with class terms: is any set also a class?
75970
$\mathbb Z[1/2]$ is not finitely generated?
16796
Zermelo-Fraenkel set theory and Hilbert's axioms for geometry
101453
Existence of a Boolean algebra with a unique ultrafilter in ZF
5964
Are there areas of mathematics (current or future) that cannot be formalized in set theory?
57021
Is the set of all functions $f:Z_+\rightarrow Z_+$ that are eventually constant countable.
9535
Why $f(z)=\frac{az+b}{cz+d}$, $a,b,c,d \in \mathbb C$, is a linear transformation?
24413
Why is $\mathbb{Z}[\sqrt{-n}], n\ge 3$ not a UFD?
38221
What is wrong with this proof there is no $\omega$-th worldly cardinal
128989
Is ${\bf Z} \times {\bf Z}$ elementarily equivalent to ${\bf Z}$?