Given an ordinal $(\alpha,\in)$, how do I find a subset of rationals which is isomorphic to it?
36325
Embedding ordinals in $\mathbb{Q}$
84374
Rational function with absolute value $1$ on unit circle
86015
$\mathbb Q[x]/(x^2+1)$ is not isomorphic to $\mathbb Q[x]/(x^2+2)$
42810
Is $(\mathbb{Q},+)$ isomorphic to $(\mathbb{Q}^n,+)$?
29160
How can one convert rational matrices into integer ones?
70409
Rational Equivalence Relation and Measure
154230
In $\mathsf{ZF}$, for each set $A$ exists an ordinal $\alpha$ such that no surjection $A\to \alpha$ exists
105146
$M$ contains all ordinals
109223
For ordinals $\delta$ and $\beta$, if $\delta\in$ or $=\beta$, then there exists $\gamma\in$ or $=\beta$ such that $\beta=\delta+\gamma$
153652
Countable ordinals are embeddable in the rationals $\Bbb Q$ -- proofs and their use of AC
136081
Indecomposable limit ordinals
132778
All distances are rational prove the set is countable
96025
Showing there is only one isomorphism between well ordered sets using transfinite induction
132298
How do you find the smallest of homeomorphic ordinals?
41846
$(\mathbb{R}^n,\|\cdot\|_{p})$ is isometrically isomorphic to $(\mathbb{R}^n,\|\cdot\|_{q})$ iff $p=q,$
63115
If $\alpha$ is an indecomposable ordinal, why $\Gamma(\alpha\times{\alpha})=\alpha$?
116594
Finite fields are isomorphic