user525966

since I do not believe there is a PM feature directly

I was just unaware how much was visible, not visible, and who could see it, etc.

or just mods?

to regular users?

If I ask a question and then edit it out or delete it later, people can still see the history right?

Yeah I don't think there is any way for me to ask it here, even bringing up the nature of the question is too much lol

I have a question but it's rather incendiary, don't know how else to ask it

Hmmm I don't suppose there is a PM feature on this thing

I don't know if people actually stuck to their guns on that or not, haven't really kept up

I was wondering if it was related to that big walk-out a while back

I see

why are mods inactive?

would you all say math is a happy or unhappy pursuit?

unfortunately not many!

@MatheinBoulomenos I agree, sort of the point I am trying to make

i'm speaking in the context of self-learning outside a school

not everyone has a teacher

becomes a challenge to sift through all the material and learn how to identify good material

there are many free resources but it's also very unstructured, not everything standardized / quality-checked, could learn bad habits or slightly incorrect things conceptually, end up with gaps, unchecked assumptions, having a lot of available material doesn't always make it easier

i understand, just saying it would be nice to see more textbooks that aren't intended for a classroom / grading setting, where practice problems and answers are provided

part of me also feels like if someone wants to cheat, they only cheat themselves

the problem is that it makes the material a lot less accessible to people unless they have the means to attend a good school with professors they can talk to and ask questions to etc, being able to talk to informed people on a regular basis is invaluable

unfortunately seems to be the case for most textbooks, very hard to get answer guides

so it takes foorrreeevvverrrr to learn anything

For someone like me (a non-student, self-learner) it's pretty infuriating because there's no way to check that my understanding is on track or that I'm doing things correctly

@TedShifrin Unfortunately most math texts don't include answer guides

unfortunately I do have to get to sleep, good night!

like nothing about it makes sense to me and I don't see what it's trying to do or what it's permitting

I don't like blindly using things I don't understand / I have no idea what E in S means or why it's needed, or how this is meant to convolve with the other conditions -- if you say it's a term and not just a variable or constant symbol, and so on, that honestly confuses me more

might be a difference of system but every other system I have come across permits this

I literally use forall elim on the next line after the header

Where once you have a for-all statement you can remove it and replace the variable with some constant to indicate that you're taking an instance

In that other system (and most that I see online) it permits things like this: chat.stackexchange.com/transcript/message/49124613#49124613

Problem is I still have absolutely no idea what that means -- I don't know what all "E" can look like, or what all "P(E)" can look like, or how this differs necessarily from "P(x)" and so on

Are these both equally valid? Does "restating" a header somehow make it a "real" instance I now have to avoid conflict with?

If ∀x ∈ S (∀y ∈ S (Q(x,y) → P(x))):
    ∀x ∈ S (∀y ∈ S (Q(x,y) → P(x)))    [restate]

    Given x ∈ S:
        ...

and then, what about:

If ∀x ∈ S (∀y ∈ S (Q(x,y) → P(x))):

    Given x ∈ S:
        ...

I know you mention that "sometimes the x's are different / not the same" because they're sort of wrapped up in their own functions, but we can always restate things in-context and at this point I don't see how it differs from declaring a variable and then needing to avoid reusing/redeclaring it

@user21820 From "∀x∈S ( P(x) )" to "P(t)" I think I get that t is already an object we have in current context, as in, we have all the objects in S and we're just taking one, but aren't we still coming up with the label "t" to describe this? Shouldn't this "t" not conflict with anything? Just because I have some_list = [4, 6, 9, 10] if I want to take one I still have to ensure that t = some_list[i] is not in conflict with another t

good night

brain is mush / about to fall asleep at my desk, calling it a night, thanks again @user21820

@XanderHenderson I'd agree with that rephrasing

He appears to be asking how many values satisfy largestPrimeFactor(primeSum(n)) = the {(n+1)/2}nd prime but for so few values I am unsure how he came about this question or why he's asking it. So I agree with your conclusion, I just wouldn't call it "borderline numerology" which is a fairly charged term.

I agree though that the post is unclear and lacks context... hard to tell what's being asked

Whether or not a pattern ends up existing or being useful, in my opinion, is something we can only really figure out by asking the question, looking for an answer, and seeing over time how the result ends up being used

@XanderHenderson To counter: One classic example is how one might notice that the number of moves involved in the Tower of Hanoi problem is 1, 3, 7, 15, 31, ... which looks like a pattern 2^n-1, but maybe you can't compute the next value to see if the pattern holds because the game starts to take too long. You don't actually know if it's a pattern, or if your pattern even holds. (And then someone can answer, "It actually does hold and you can prove it with induction..." and so forth).