D1, D2, D3.

D4, D5, D6.

D7, D8, D9.

D10, D11, D12.

D13, D14, D15.

C1, C2, C3.

C4, C5, C6.

C7, C8, C9.

This question is missing a close vote, and so is this one.

@darijgrinberg Please don't be disingenuous. At the time the question was closed, it looked like this: math.stackexchange.com/revisions/3372688/1

What does the asker mean by a "decomposition"?

What does it mean for a manifold to be "prime"?

What kind of manifolds are we discussing (topological manifolds, smooth manifolds, etc.)?

What is the context of the question (if mathematical physics, one might assume one set of tools; if algebraic topology, one might assume another set of tools)?

The current version of the question is much improved, though it is not at all clear to me that the current version actually addresses the original asker's concern.

Personally, I would have preferred it if Moishe Kohan had left the original question alone, and asked the question they produced as a new question, rather than hijacking someone else's question.

They could have then attached their answer to the new question, and allowed the original question to be deleted or clarified by the original asker.

Ah, another post-mortem edit. Well, I think it's still worth keeping now that it has been fixed

@darijgrinberg I don't disagree. As I said, the current version of the question is much improved.

If Moishe had asked and answered that version of the question, I may have gone so far as to upvote both question an answer.

However, I am concerned that the original asker will come back, say "That wasn't what I meant", make some destructive edits, and invalidate the answer.

As that seems like a narrow possibility, I have no problem leaving the question as-is.

Here you go if you have any good and easy ideas for masters theses that you want to get rid of math.stackexchange.com/q/3389069/29335

[ SmokeDetector | MS ] No whitespace in body (98): Series series series series ✏️ by user243851 on math.SE

The notion of "prime decomposition of manifolds" is completely standard. Just because you are not familiar enough with the field to understand a question does not mean it is lacking in context.

@EricWofsey The notion of an open set is completely standard. The $\varepsilon$-$\delta$ definition of continuity is completely standard. The ratio test for the convergence of a series is completely standard. I would still expect an asker to define these terms if they were central to the question being asked.

If the question boils down to "Can a foo be understood as a kind of bar?", then I would expect both foo and bar to be defined in the question. At the very least, the asker should provide a reference for the definition.

@XanderHenderson FWIW I'm actually quite ok in radically editing an advanced question. I think I advocated the practice in meta. Mind you, I would prefer the edit to be done by somebody other than the answerer, but on a relatively advanced question it may be difficult to find another editor who can confidently do it. Of course, an edit does not salvage a duplicate.

@JyrkiLahtonen My objection to hijacking a question is a fairly mild one. I don't think that it is "best practices," but I'm also not going to raise a stink about it, in general. There are those who frequent this room who are more militant about it. :)

With respect to the question which prompted this discussion, I think that the current version is fine; I just think that there may have been, in principle, a better way of handling things. But, lacking a time machine, the current state of the universe is hunky-dory.

@user170039 More about the difference between type 3 and type 5. I would make a distinction, if the user also actively participates in site maintenance: searches for dupes, votes to close accordingly, etc.

Even that is not clear-cut. Some type 5s indulge in what I internally call "stunning displays of banality", basically reproducing definitions and such. I'm unhappy with that. I have seen many students get confused with a definition, but such questions don't make for good content IMO. "Too localized". Admittedly this aversion may say more about me than about the site.

We have a few operators who have made me allergic to answers composed with under 10 minutes of thought. That's a low hanging fruit.

Attitude to low hanging fruits may be the main peeve.

@JyrkiLahtonen I am not aware of a single user who fits that definition. More projection on your part? The site would be much more pleasant if some users (esp. you) refrained from making unfounded wild guesses about the motivations of others.