Cardinality of a finite $\sigma$-algebra
64118
Number of elements in a finite $\sigma$-algebra
50241
Cardinality of the quotient ring $\mathbb Z_5[i]/\langle 1+i\rangle$
10702
Show that $\left\{A\subset\Omega: A~\text{ is countable or }A^C\text{ is countable}\right\}$ is a $\sigma$-algebra
7785
Cardinality of sum-set
78256
Finite additivity in outer measure
103427
When is $\operatorname{Hom}_A(M,N)$ finitely generated?
38946
Show that $\{\cup_{n\in K} (n, n+1]: K \subset \mathbb{Z}\}$ is a $\sigma$-algebra on $\mathbb{R}$
151928
How to prove that $N\setminus A$ is finite?
87203
Preimage of generated $\sigma$-algebra
79974
The cardinality of Lebesgue sets
104744
Can sets of cardinality $\aleph_1$ have nonzero measure?
144735
Possible cardinality of power sets
146951
Every countably generated sigma algebra is generated by a random variable
144787
Show that the set of all infinite subsets of $\mathbb{N}$ has cardinality greater than $\mathbb{N}$
66301
The cardinality of the set of countably infinite subsets of an infinite set
10247
What is the minimum $ \sigma$-algebra that contains open intervals with rational endpoints
155168
Is the collection of finite subsets of $\mathbb{Z}$ countable?