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seen May 10 at 18:00

May
5
comment A question about simple closed curves in finite dimensional Euclidean spaces
Thanks for the clarification
May
3
comment A question about simple closed curves in finite dimensional Euclidean spaces
Many thanks for such a complete answer. I am not too familiar with homology theory so it may take me awhile to fully understand your proof.
May
3
accepted A question about simple closed curves in finite dimensional Euclidean spaces
May
2
asked A question about simple closed curves in finite dimensional Euclidean spaces
May
1
comment A question about Cantor's Power Set theorem without the Axiom of Choice
You are right. I was finally able to digest all the steps of your proof. Proving theorems about all infinite cardinal numbers can be quite tricky when the Axiom of Choice is not available.
Apr
30
comment A question about Cantor's Power Set theorem without the Axiom of Choice
In ZF set theory without the Axiom of Choice, there exist infinite sets X which are neither Alephs nor Dedekind-finite. Is it still true for such sets that CARD(2^X) is greater than 2*CARD(X)?
Apr
29
comment A question about Cantor's Power Set theorem without the Axiom of Choice
Thanks for the neat proof-in ZF without the Axiom of Choice-that CARD(X(I)) is greater than CARD(X) when X is infinite.
Apr
29
accepted A question about Cantor's Power Set theorem without the Axiom of Choice
Apr
28
asked A question about Cantor's Power Set theorem without the Axiom of Choice
Apr
4
awarded  Popular Question
Mar
6
awarded  Yearling
Mar
3
comment Questions about a possible way of representing construcive ordinal numbers
I was trying to work out whether any useful notation systems for a segment of the countable ordinal numbers could be developed, using recursive functions-or even just primitive recursive functions-as the notations. When you pointed out the existence of subsets of K which are densely ordered by "<", I saw what was wrong with this idea and why Hardy (who, I believe, first investigated the ordering "<") never went very far with it.
Mar
2
accepted Questions about a possible way of representing construcive ordinal numbers
Mar
1
comment Questions about a possible way of representing construcive ordinal numbers
Please disregard this last comment
Mar
1
comment Questions about a possible way of representing construcive ordinal numbers
I seem to have lost most of my question
Mar
1
asked Questions about a possible way of representing construcive ordinal numbers
Feb
28
comment A question about open subsets of Hilbert space whose complements are compact sets
V is a G-delta set (an intersection of a countable sequence of open sets). Since you have shown V to be both connected and locally connected, it follows that V is also arc-wise connected.
Feb
27
comment A question about open subsets of Hilbert space whose complements are compact sets
Many thanks for the proof which I was not quite able to find for myself
Feb
27
accepted A question about open subsets of Hilbert space whose complements are compact sets
Feb
26
asked A question about open subsets of Hilbert space whose complements are compact sets