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May
27
comment Questions on Fraenkel models
I will accept the answer that contains the most information relevant to my questions. As of now this is your answer even though it doesn't address all of them. The most relevant part in this whole thread being your last paragraph which seems to confirm that ZFA is not all that useful. While sort of contained in Asaf's "Asafian Monolgue", without reading your paragraph first, the information encoded there would not have been accessible to me. I am not saying that Asaf's answer is bad, nor that I am stupid but merely that Asaf and my brain are incompatible.
May
27
comment Questions on Fraenkel models
No problem at all, take all the time you want. I am not planning to accept one of the other two answers and I really appreciate that you would edit your answer for me. (Although I vote for you, seeing this little diamond just now was a bit of a shocker for a second : D)
May
27
comment Questions on Fraenkel models
I'm sorry, my question 2.b) is (rephrased) "does ZF with modified Extensionality imply modified Empty Set". I can't decide from the first part of your answer whether the answer is yes or no. Would you mind rephrasing that part? I will take the absence of your mention of my question 1 as meaning that you don't know. And lastly, can one interpret your second part as "in general, models of ZFA (without transferring) are only useful to give hints about ZF"? Thank you in advance.
May
27
comment Questions on Fraenkel models
@AsafKaragila My question, even though it contains AC, is not actually about AC. I merely used it as an example.
May
27
comment Complete list of Sierpiński's publications
You're very welcome. But don't be so grateful -- it's 10 points for every hour you saved me. Plus I'm still overjoyed about having obtained a digital copy of the 3 volumes of œuvres choisies which I meanwhile have snipped in the middle so that it's now ready to be made into a fully-functional paper copy. : )
May
27
comment Another question about Cohen's article
I certainly find what you say useful! And I apologise again for taking so long to accept your answers. It's a lot of facts about forcing and models to grasp for me at once.
May
26
comment Complete list of Sierpiński's publications
Yeah, I didn't see the sneaky "See other formats" button. The site looked like a scam site to me and then my "filter" set in.
May
26
comment Complete list of Sierpiński's publications
You are awesome and a lifesaver! Thank you so much. (I had ended up here by googling but failed to make sense of it.)
May
26
comment Complete list of Sierpiński's publications
I'm sorry to bother you but do you know how one can access "Sitzungsberichte der Preussischen Akademie der Wissenschaften Phil.-math. 1922, 253–257"? I tried Daivd's suggestion but then I can't seem to view the full article here on Jahrbuch Database.
May
26
comment Out-of-print textbooks that should be reprinted
Awesome idea! How are your business plans making progress?
May
25
comment On Lévy collapsing the reals
@AsafKaragila If you can get hold of Lévy's originals that would be more than super-awesome. With enough time I'll understand it and it'll be interesting to read. (As for my previous comment: on the bright side it means that I'm on the right track albeit several steps behind the asker of the question)
May
25
comment On Lévy collapsing the reals
Now that I dug up the Bell-Fremlin paper I realise that tb must've had all these thoughts already. Oh well.
May
25
comment On Lévy collapsing the reals
@AsafKaragila Thank you for confirming its non-existence. And for the link.
May
25
comment On Lévy collapsing the reals
@AsafKaragila I want to read Levy's paper.
May
25
comment On Lévy collapsing the reals
@AsafKaragila Ah, thanks. If I had access to the original paper...
May
25
comment On Lévy collapsing the reals
@AsafKaragila Sorry, that should have been "a Lévy model". A model in which there exists a bijection between the natural numbers and an $\aleph$ greater than $\aleph_0$.
May
25
comment On Lévy collapsing the reals
@AsafKaragila Do you also know the title of the original paper? As for the properties: I mean which theorems are true and which are false. For example, in Cohen's first model Krein-Milman is false. What if OMT is true in Levy's model? (Probably not, but maybe it is).
May
25
comment On Lévy collapsing the reals
By Kanamori, do you mean his book on the higher infinite?
May
25
comment On Lévy collapsing the reals
@AsafKaragila I want to read about properties of the resulting model. Wouldn't that be in Lévy's original paper? Alas, I don't know the title of it.
May
25
comment On Lévy collapsing the reals
@AsafKaragila And my other question in the post: where can I read about the Levy collapse? Jech's mention of it is minimal.