Stack Exchange

Henno Brandsma

the Netherlands

http://at.yorku.ca/cgi-bin/bbqa

Dutch topologist, now working in other fields.
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Top Questions
Top Answers
104
Elementary proof that $\mathbb{R}^n$ is not homeomorphic to $\mathbb{R}^m$
math.stackexchange.com

97
A map is continuous if and only if for every set, the image of closure is contained in the closure of image
math.stackexchange.com

92
How secure is Chrome storing a password?
security.stackexchange.com

83
Projection map being a closed map
math.stackexchange.com

72
Is $\mathbb R^3$ the square of some topological space?
mathoverflow.net

55
Prove $\limsup\limits_{n \to \infty} (a_n+b_n) \le \limsup\limits_{n \to \infty} a_n + \limsup\limits_{n \to \infty} b_n$
math.stackexchange.com

51
Show that the countable product of metric spaces is metrizable
math.stackexchange.com

47
Proof that product topology of subspace is same as induced product topology
math.stackexchange.com

33
Quick proofs of hard theorems
mathoverflow.net

31
Locally Constant Functions on Connected Spaces are Constant
math.stackexchange.com

30
Why do we need topological spaces?
math.stackexchange.com

28
What are the issues in modern set theory?
math.stackexchange.com

26
Continuous image of a locally connected space which is not locally connected
math.stackexchange.com

25
Perfect set without rationals
math.stackexchange.com

25
A topology that is finer than a metrizable topology is also metrizable?
math.stackexchange.com

24
What is the reason for the term "zero dimensional" in the context of topology?
math.stackexchange.com

24
Any open subset of $\Bbb R$ is a countable union of disjoint open intervals
math.stackexchange.com

23
Topology vs Borel sigma-algebra on a set $X$
math.stackexchange.com

23
No. of possible dense subsets of a metric space
math.stackexchange.com

22
Why is the lower limit topology not metrizable?
math.stackexchange.com

22
A quotient of a locally connected space is locally connected
math.stackexchange.com

21
Is every manifold a metric space?
math.stackexchange.com

21
$f$ is Continuous if and only if its Graph is Closed in $X \times Y$
math.stackexchange.com

21
Are the rationals minus a point homeomorphic to the rationals?
math.stackexchange.com

21
What is your favorite proof of Tychonoff's Theorem?
mathoverflow.net

21
Definitions of Baire first and second category sets
math.stackexchange.com

21
Make $2^8 + 2^{11} + 2^n$ a perfect square
math.stackexchange.com

20
Locally compact Hausdorff space that is not normal
mathoverflow.net

20
Proving that a Banach space is separable if its dual is separable
math.stackexchange.com

19
Can Cantor set be the zero set of a continuous function?
mathoverflow.net

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