u/mandemting03

Is this a good book to learn about logic in general?

Not necessarily looking to go super deep into formal logic but just get a good idea of logic.

Copi's(which I know is a standard formal logic book) vs Kreeft

Thanks

I'm trying to get accurate historical data.

I always hear about Dukascopy. But when I go on the website there are fairly restricting limits and the export doesn't even allow daily data.

Do I have to sign up to Dukascopy and go through a KYC just to access the data? Are there any other reputable free sources?

In addition. What are some reputable PAID sources for accurate historical FX data (But not ridiculously expensive)

Thank you very much.

Hello. I'm still getting very confused about "if" and "only if" when it comes to introductory formal logic.

The sentences linguistically are making it very hard to accept the definitions.

1. If A then B (otherwise said as "B if A"): A--->B

This one is simple to grasp. A will always be followed by B but not vice versa. From this we can also deduce "if not B then not A"

Although sometimes I get into this idea that if A happens and then B happens means B happened with A so why can't we say "If B then A" as well? Is it a time order thing?

2. Only if A then B (B only if A): B ---> A

This is the one I still can't accept. Linguistically, the word "then" always gives me the impression that B comes after A(like in a time sequence), as in A must happen in order for B to happen and thus it should A--->B. The explanation of a necessary condition doesn't seem to override my intuition which makes it a bit difficult to accept the definition of "only if".

Any suggestions on how to override this incorrect intuition?

Thanks

I have very recently been introduced to the world of "intelligence maxing"(so the internet calls it these days)

So I decided to go down this rabbit hole and other than the generic advice of exercise,sleep and eat well, these are the 3 techniques that are consistently mentioned: Quad-N-back, Syllogimous(RFT) & Logic Grid Puzzles

I decided to check what experience people have with these and it's quite interesting to see where some people swear by it whereas others are very adamant it's pointless.

But I haven't seen anyone actually compare which techniques seem to be the best so I wanted to ask those of you that have tried at least 2 of these techniques what are your experiences? And are they worth the struggle

Thanks

This question popped up in my head after I posted this thread about differential vs derivative so it's more like a follow up.

Is an integral the opposite of a derivative? It seems like it isn't now that I think about it.

Take

1. dy=f'(x) * dx

Integrate it you end up with

2. y=f(x)

Then take the derivative of 2) and you end up with

3. dy/dx = f'(x)

But 3) isn't the same as the original equation 1)

That is we somehow went from having differentials(dy & dx in the 1st equation) to only ending up with a derivative in the 3) equation.

AI is telling me that we must carry out a differential operation and not a derivative operation on equation 2 to end up back at the original equation, but I don't trust AI too much on these logical confusions.

My understanding is that derivatives come first and then the differential equation can be defined.

For example, the following equation

1. dy = dy/dx * dx also written as 2) dy = f'(x) * dx

the dxs don't actually cancel out since dy/dx is not a fraction but rather a notation for the derivative.

So it would be more clear to define the equation as

dy(differential) = dy/dx(derivative) * dx(differential)

Is my understanding correct? Thank you

Hello. I have been meditating for the last couple of months, but I'm not sure I'm doing it completely right still. I would like someone to explain it a bit more so I don't overthink the whole thing.

From my understanding when one meditates the idea is to concentrate on a primary object(Usually the breath is the most common example) and whenever one notices that the mind is wandering away into its own random pop-up thoughts to bring the attention/focus back to the primary object.

I do this. However, what's interesting is that in just observing my own breath, I no longer become just an observer but rather an interrupter of a natural involuntary process hence in a way, unwillingly I influence my own breath by observing it (but this also proves that I am indeed focused on it). This leads to sometimes unsatisfactory fragmented breathing(where either I overbreathe or underbreathe and just experience mild "air-hunger") but for the most part it's fine.

Another thing I've noticed is that as I meditate and enter a deeper semi-sleepy/relaxed state(but always keeping focus on the breath so as to not actually drift to sleep) the rate of my breathing naturally decreases and thus there are long stretches between breaths where my breath just totally stops naturally and to try to force myself back into breath goes against the meditative process and is just uncomfortable.

However, it Is precisely when the body is completely still and not breathing that I catch my brain wandering, but since I am not breathing there is nothing to focus on(and again to try to force myself to breathe is uncomfortable so I let my body be) so what I naturally do is just say "No" repeatedly in my mind whenever I notice that my mind begins to wander into its own thoughts.

What is one supposed to do in these cases? And am I correct in understanding that as you go deeper into meditation you enter a semi-sleepy state(but never actually sleeping because you're still focused on your breath).

Thank you very much.

https://asker1997.github.io/posts/ceo.html

Just wanted to ask if this is a decent start for a project for someone who is interested in quant/trading.

Thanks

I'm trying to navigate the KTEL Bus website but it's very confusing since they don't write the intermediate stops and nor do they write the times for the reverse line (i.e. Agios Ioannis-Ornos-Fabrika and not just Fabrika-Ornos-Agios Ioannis) so I can't trust it too much.

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Also what does Ornos even mean? There are 3 bus stops in Ornos(One near Pasaji beach club, one on the other side of Ornos, and one near Erato Hotel Mykonos)

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The website says the last bus from Fabrika to Ornos is 1:30 AM whereas everywhere else it says it's 23:30.

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If anyone could help me out or even direct me to a better timetable(unlikely since KTEL is the official website but I'm asking on the offchance someone might know), i'd be grateful.

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Thanks

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Hello

I would like to start learning about logical thinking(I enjoy the brain teases). I came across a book by Siu Fan Lee.

I checked online to see any reviews and came across a thread where they say that some of the things that are written are completely wrong.

Logic is quite tricky to begin with (let alone for someone who has never studied it). So I want to be sure I'm studying accurate/correct explanations and not running around in circles scratching my head trying to figure out something just because the author made mistakes in their explanations OR even worse I accept incorrect information as the logical truth(no pun intended)

If you have a book that is accurate/correct in its explanations and that deals in an introductory manner with the topics of categorical logic, propositional and predicate logic(The main ones in Siu Fan Lee's book from my understanding) I'd be grateful

Thank you very much