No single axiom stating non-Archimedeanity
37116
Do ordered fields and archimedian ordered fields have the same first-order theory?
86233
A $3 \times 3 \times 3$ cube has no Hamiltonian path starting at the corner.
125161
Why is the Cartesian product of $A$ and $\varnothing$ empty?
74281
Proof there is no largest cardinal number
108488
Why aren't vacuous truths just undefined?
128524
Proving there is no analytic function
4946
Non-existence of irrational numbers?
114650
In Cantor's Diagonalization Argument, why are you allowed to assume you have a bijection from naturals to rationals but not from naturals to reals?
28452
Statement that is provable in $ZFC+CH$ yet unprovable in $ZFC+\lnot CH$
98731
Show that there is no epimorphism from ($\mathbb{Q}$, +) to ($\mathbb{Z}$, +)
53399
Proof of the uncountability of reals using the diagonal argument—problem?
110957
No non-trivial clopen sets in $\mathbb{R}$? How to give a direct proof?
58447
Is axiom of choice required for there to be an infinite linearly independent set in a (non-finite-dimensional) vector space?
88566
Is denying "Paradoxical Partitioning" equivalent to accepting the Axiom of Choice?
52949
If $aRb \land bRc$ never occurs, is a relation considered transitive?
126862
Confused about $x \notin x$ example in Axiom of Specification
38221
What is wrong with this proof there is no $\omega$-th worldly cardinal