Cardinality/Set Theory
6788
Let $(a,b)$ and $(c,d)$ be intervals in $\Bbb R$, and find an injective and surjective function from $(a,b)$ to $(c,d)$
86988
Cardinality of the Irrationals
121366
Intervals and cardinality
17987
Which of the following sets has the greatest cardinality?(Math subject GRE exam 0568 Q.61 )
109968
Let $X= \{ A \subset \mathbb{N} : \mathbb{N} \backslash A \text{ is finite}\}$. What is the cardinality of $X$? Prove it.
73850
Cardinality of set of functions
34710
Cardinality of Irrational Numbers
144787
Show that the set of all infinite subsets of $\mathbb{N}$ has cardinality greater than $\mathbb{N}$
31318
Cardinality of cartesian square
89167
Cardinality of equivalence relations in $\mathbb{N}$
82947
Undecidable cardinality
83518
Proving Two sets have same cardinality
85099
How many subsets of $\mathbb{N}$ have the same cardinality as $\mathbb{N}$?
81509
The cardinality of a countable union of countable sets, without the axiom of choice
101669
Cardinality of the Set of all finite subset of $\mathbb{R}$
77286
Proving set theory question
18364
When does the set enter set theory?