Relation between limit ordinals and alephs.
3135
Is a limit ordinal necessarily a cardinal?
109223
For ordinals $\delta$ and $\beta$, if $\delta\in$ or $=\beta$, then there exists $\gamma\in$ or $=\beta$ such that $\beta=\delta+\gamma$
43197
Showing that two definitions of $\limsup$ are equivalent
126516
Under what condition we can interchange order of a limit and a summation?
121860
Number of well-ordering relations on a well-orderable infinite set $A$?
38242
Explicit bijection between the successor of $\alpha$ and $\alpha$ (infinite ordinal).
138713
Alpha and Omega limit sets (dynamical systems)
23076
Proof of limit of quotient sequence property
50043
Limit of sequence in which each term is defined by the average of preceding two terms
131163
There is a well ordering of the class of all finite sequences of ordinals
64500
$\aleph_1 = 2^{\aleph_0}$
146826
Fibonacci Sequence and series limits
67420
Limit of quotient sequence
156663
Interchanging limit with infimum/supremum
83130
How are these definitions of the limit superior and limit inferior equivalent?
19924
Uncountable ordinals without power set axiom
137534
For what ordinals does $1+\alpha=\alpha$ hold? For what ordinals does $2\alpha=\alpha$ hold?