Difficulty in understanding the proof : S must have infinitely many accumulation points.
99854
Must an uncountable subset of R have uncountably many accumulation points?
140364
Covering ten dots on a table with ten equal-sized coins: explanation of proof
105107
How to explain the following definition of $\lim\sup s_n$ intuitively?
66301
The cardinality of the set of countably infinite subsets of an infinite set
111449
Prove there is an increasing sequence ($s_n$) of points in $S$ such that $\lim s_n = \sup S$.
6478
Prove that for any infinite poset there is an infinite subset which is either linearly ordered or antichain.
32524
Flawed proof that all positive integers are equal
41298
Understanding proof of completeness of $L^{\infty}$
137990
Justify each step in the following proof of Proposition 3.9 (a). I like to know if I'm in the right track and I'm also missing a few of them
81682
Proving the algebraic set corresponding to a polynomial is infinite.
107381
Understanding the proof of infinitely many primes $\equiv 3\pmod{\!4}$
102202
The smallest infinity and the axiom of choice
137308
If an IVP does not enjoy uniqueness, then it possesses infinitely many solutions
120599
Points of a Measure Zero Sets Covered by Intervals Infinitely Many Times
48278
Inequality about infinite cardinals
81124
Infinite product problem: $\sum p_n0$
155777
Show that infinite Cartesian product is uncountable