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Harry Altman's user avatar
Harry Altman's user avatar
Harry Altman's user avatar
Harry Altman
  • Member for 13 years, 5 months
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Currently studying the complexity of natural numbers in various simple computational models, and occasionally unusual operations on ordinals. See website for more.

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All Questions Answers
Score Newest
answer
69
What are the most attractive Turing undecidable problems in mathematics?
Apr 28, 2010
answer
42
Examples of common false beliefs in mathematics
May 14, 2016
answer
34
Examples of seemingly elementary problems that are hard to solve?
Sep 18, 2011
question
28
Are Minkowski sums of upward closed "convex" sets in $\mathbb{N}^k$ still "convex"? (WAS: Comparing mana costs in Magic: The Gathering)
Oct 18, 2017
answer
28
Axiomatic definition of integers
May 1, 2010
answer
27
Not especially famous, long-open problems which anyone can understand
Jul 26, 2012
question
26
Surreal exponentiation -- are the varying definitions equivalent? If not, is there agreement on which ones are better?
Feb 19, 2012
question
19
What is the fairest order for stage-striking (and is it the Thue-Morse sequence)?
Nov 21, 2018
question
18
What if homotopy were expanded to allow any connected space instead of $[0,1]$?
May 2, 2015
answer
17
Examples of common false beliefs in mathematics
Feb 6, 2011
Top network posts
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122
Continuity of the roots of a polynomial in terms of its coefficients
44
Are all $p$-adic number systems the same?
19
How to show $\ell^2_p$ not isometric to $\ell^2_{p'}$ unless $p\in\{1,2,\infty\}$?
17
Basic counterexample re: preimages of ideals
14
Entire function with $f(z)=\sin(f(z))$ must be constant?

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