The "difference" of two ordinals
133870
if $\alpha\leq\beta$ then there is $\gamma$ such as $\alpha+\gamma=\beta$
127233
Cardinality of order types in $\mathbb{N}$
36325
Embedding ordinals in $\mathbb{Q}$
63618
Can all ordinals be obtained by taking successors and countable limits?
147508
Ordinal trends and finding concordant and discordant pairs
26592
The symmetric Difference
131841
Difference of closures and closure of difference
109959
Calculate mean of ordinal variable
16971
Prove that no ordinal is an element of itself
21229
If an element is not in the set difference $A\setminus B \: \:?$
39405
Symmetric difference = Ø
98931
Comparing the values of two generic Numbers
38083
Order of conjugate of an element given the order of its conjugate
2635
equality of two operators...
25713
If $a$ and $b$ commute and $\text{gcd}\left(\text{ord}(a),\text{ord}(b)\right)=1$, then $\text{ord}(ab)=\text{ord}(a)\text{ord}(b)$.
63149
Notation for functions vs. numbers
71272
Scoring predictions of an ordinal variable