current community
chat
MathOverflow
MathOverflow Meta
your communities
Sign up
or
log in
to customize your list.
more stack exchange communities
company blog
Stack Exchange
Inbox
Reputation and Badges
sign up
log in
tour
help
Tour
Start here for a quick overview of the site
Help Center
Detailed answers to any questions you might have
Meta
Discuss the workings and policies of this site
About Us
Learn more about Stack Overflow the company
Business
Learn more about hiring developers or posting ads with us
MathOverflow
Questions
Tags
Users
Badges
Unanswered
Ask Question
Profile
Activity
Andreas Blass
Meta User
Network Profile
Reputation
47,391
47.4k
35.3k
23.2k
2013
2014
2015
2016
Next tag badge:
ultrafilters
124/100 score
19/20 answers
Badges
6
96
179
Newest
Enlightened
Next badge
0/1
Excavator
Impact
~
861k
people reached
24 posts edited
19 helpful flags
557 votes cast
summary
answers
questions
tags
badges
favorites
bounties
reputation
all actions
629
Answers
newest
activity
votes
167
What are some examples of colorful language in serious mathematics papers?
Apr 24 '10 at 21:26
102
Mathematical “urban legends”
Jan 25 '11 at 16:26
60
Categories First Or Categories Last In Basic Algebra?
Oct 4 '10 at 22:23
40
Why can't proofs have infinitely many steps?
Aug 29 '10 at 18:54
38
Is Euclid dead?
Dec 19 '13 at 18:59
35
Set theories without “junk” theorems?
Mar 11 '12 at 22:37
35
What is Realistic Mathematics?
Aug 7 '10 at 20:22
33
When factors may be cancelled in homeomorphic products?
May 30 '10 at 4:12
32
Kuratowski's definition of ordered pairs
Apr 24 '11 at 0:09
29
Do the algebraic integers form a free abelian group?
Dec 22 '11 at 19:43
28
Historical (personal) examples of teaching-based research
Apr 1 '15 at 19:29
28
Mathematicians who made important contributions outside their own field?
Jul 4 '14 at 17:29
28
Can the symmetric groups on sets of different cardinalities be isomorphic?
Apr 23 '12 at 13:56
28
What the heck is the Continuum Hypothesis doing in Weibel's Homological Algebra?
Jun 22 '11 at 13:54
27
Unprovable statements S where the only way to prove S is to assume S
Nov 8 '12 at 15:13
27
What can be proven in Peano arithmetic but not Heyting arithmetic?
Feb 12 '12 at 2:40
27
Interpretation of the Second Incompleteness Theorem
Sep 9 '10 at 17:59
27
Is there a name for a family of finite sequences that block all infinite sequences?
Jun 27 '10 at 6:34
26
Is Monsky's theorem depending on axiom of choice ?
Sep 12 '12 at 21:17
26
Set theories without “junk” theorems?
Mar 10 '12 at 16:38
26
Arguments against large cardinals
Oct 30 '10 at 15:12
25
When does Cantor-Bernstein hold?
Jul 18 '10 at 22:08
25
Why is the fibered coproduct of affine schemes not affine?
Jun 24 '10 at 2:12
24
About the proof of the proposition “there exists irrational numbers a, b such that a^b is rational”
Feb 28 '11 at 22:37
23
Direct product of filters
Aug 10 '11 at 23:54
23
Is PA consistent? do we know it?
May 27 '11 at 1:46
23
Is P=NP relevant to finding proofs of everyday mathematical propositions?
Dec 2 '10 at 18:51
22
Why is there a need for ordinal analysis?
Dec 3 '15 at 11:20
22
What defines a “short proof”?
Apr 28 '15 at 1:01
22
Research topics restricted to students at top universities?
Jun 7 '13 at 0:40
MathOverflow works best with JavaScript enabled