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bio website thales.doa.fmph.uniba.sk/…
location Bratislava, Slovakia
age 36
visits member for 4 years, 9 months
seen 14 hours ago

1d
comment A book for problems in Functional Analysis
Also Fabian, Habala, Hájek, Montesinos, Zizler: Banach Space Theory, The Basis for Linear and Nonlinear Analysis has a lot of exercises.
1d
revised A book for problems in Functional Analysis
minor typo
May
17
comment On the independence of lower and upper asymptotic and Banach densities
Changing a set $A$ to $B=\{\lfloor ca \rfloor; cA\}$ for $c\in(0,1)$ changes all four densities with factor $c$. So it is sufficient to prove the case $\delta=1$. (Which is not much of a simplification, but perhaps it helps at least a bit.)
May
16
comment On the independence of lower and upper asymptotic and Banach densities
I just want to confirm that I cannot find a reference you ask for and I have probably seen result for some other kind of densities. (Which means the my answer back then was partially misleading. Although, this was probably not the most important part of that answer.)
May
16
revised Density of a set of natural numbers whose differences are not bounded.
added 243 characters in body
May
1
revised Which popular games are the most mathematical?
old link to an image was not working; I replaced it by imgur link converted from https://upload.wikimedia.org/wikipedia/commons/4/4b/Sokoban_ani.gif
Feb
19
revised Uniqueness of minimal completions of a partially ordered set
typos: MacNielle -> MacNeille; added links
Feb
19
suggested approved edit on Uniqueness of minimal completions of a partially ordered set
Jan
15
comment name for “solid” subset of a partially ordered set?
It is probably not worth bumping 5 years old post with such a trivial edit, but for the sake of better readability, the condition is: If $a,c\in S$ and $b\in P$ and $a\le b\le c$ then $b\in S$.
Jan
10
revised Best online mathematics videos?
added (online-resources) tag; this tag was discussed here: http://chat.stackexchange.com/rooms/10243/conversation/online-resources-tag
Dec
28
comment Subset of the plane that intersects every line exactly twice
There is also freely available paper Erdös, P., and Bagemihl, F.. "Intersections of prescribed power, type, or measure." Fundamenta Mathematicae, eudml.org/doc/213347, matwbn.icm.edu.pl/ksiazki/fm/fm41/fm4119.pdf
Dec
28
revised Subset of the plane that intersects every line exactly twice
minor typo; added jstor link
Dec
28
suggested approved edit on Subset of the plane that intersects every line exactly twice
Dec
12
revised How prove this polynomial inequality from a book
minor typos
Dec
12
comment How prove this polynomial inequality from a book
Here is Google Books link to the reference given by Lucia. I would be quite curious to know the name of the book where you saw this problem.
Dec
12
suggested approved edit on How prove this polynomial inequality from a book
Dec
3
comment Hausdorff spaces with trivial automorphism group
There is also a series of papers by Kannan and Rajagopalan on the topic of rigid spaces. You can find there some further constructions and references. They also study strongly rigid spaces, which you mention in another question.
Nov
18
comment Stone-Cech compatification and ultrafilter
You can also have a look at these notes of mine which include proofs of some facts about ultrafiter construction of $\beta\mathbb N$. I would say the proofs there are quite detailed.
Nov
18
comment Stone-Cech compatification and ultrafilter
If you can be more specific, perhaps you could make a suitable question for math.SE from this. Asking not so specific question seems to be more suitable for chat. Over there at math.SE we have General Topology chatroom which is rather inactive these days. However, you need at least 20 reputation points to talk in chat. I am not sure whether you need 20 points on math.SE or 20 points on any site would suffice.
Nov
2
comment “a shape that … lies halfway between a square and a circle”
Since my suggested edit was rejected, I'll just point out in a comment that it is preferred to embed images using the editor/imgur instead of using external links to prevent link rot (as discussed on meta).