/sci/ - Science & Math » Thread #14394923

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i can't believe it

Anonymous Thu 14 Apr 16:19:03 2022 No.14394923 View Reply Original Report

i'm getting filtered by logical implication

i simply do not understand how if a premise is false and the conclusion is true, that means the premise implies the conclusion (meaning p-> q is true). Even worse, if there is a false premise and a false conclusion, how is it that the premise imply the conclusion???

Anonymous

Anonymous Thu 14 Apr 2022 16:24:00 No.14394947 Report

Quoted By: >>14394995 >>14394999 >>14395016 >>14395461 >>14396866

im a sales man, i promise you that if you get my product your dick become hard

p = you get my product
q = your dick become hard

you get the product and your dick become hard.
you get the product but your dick is not hard.
you dont get the product but your dick become hard.
you dont get my product and your dick is not hard.

Anonymous

Anonymous Thu 14 Apr 2022 16:24:14 No.14394949 Report

Quoted By: >>14395195 >>14400293 >>14400733

>>14394923
To give you an example for p = T and q = F

If all niggers commit crimes, then all niggers should be sent to Africa.

first proposition: all niggers commit crimes
second proposition: all niggers should be sent to Africa

While the first is false, and the second is true, how does the first imply the second? It doesn't make sense to me. Isn't this what they call non sequitur?

Example for p = F and q = F

If all weebs like moe, then all weebs like shonen.

first proposition: all weebs like moe
second proposition: all weebs like shonen

Why does the first proposition imply the second, though both are false?

Anonymous

Anonymous Thu 14 Apr 2022 16:29:31 No.14394974 Report

Quoted By:

>>14394923
It's a consequence of accepting contraction of hypotheses.

Anonymous

Anonymous Thu 14 Apr 2022 16:36:37 No.14394995 Report

Quoted By:

>>14394947
That means your product is sufficient but not necessary to stiffen my willy.

Anonymous

Anonymous Thu 14 Apr 2022 16:37:17 No.14394999 Report

Quoted By: >>14395041

>>14394947
>you get the product and your dick become hard.
Therefore the product implies erection, good

>you get the product but your dick is not hard.
Therefore the product doesn't imply erection, good

>you dont get the product but your dick become hard.
Therefore not getting the product (ie p = F) implies erection?

>you dont get my product and your dick is not hard
Therefore not getting the product implies non erection (ie p and q = F)?

I think I get it, the key to understand the last two cases is to negate the propositions

Anonymous

Anonymous Thu 14 Apr 2022 16:45:27 No.14395016 Report

Quoted By:

>>14394947
25-50-25
something failed - dick power - everything failed

Anonymous

Anonymous Thu 14 Apr 2022 16:46:21 No.14395019 Report

Quoted By:

>>14394923
Normally, when we say that X implies Y, we mean there's a necessary logical connection between X and Y; but as you've discovered, that's simply not what the -> operator in boolean logic means, even though it's called "implication".

Anonymous

Anonymous Thu 14 Apr 2022 16:53:16 No.14395040 Report

Quoted By: >>14395062 >>14395211

>>14394923
The other tards make it complex. Simple answer is logic in math has no correspondence to the real world. There is absolutely no causal relationship between p and q. Its clearer if it's nonsense.

My dick is loud implies taxes are pink.

If my dick isn't loud, it implies nothing, so the statement is true regardless of what color taxes are.

Anonymous

Anonymous Thu 14 Apr 2022 16:53:37 No.14395041 Report

Quoted By: >>14395050 >>14395062

>>14394999
you really overthink this, the key to understand that this logic is compatible with cases like promises.
i promise you that if you do y you get x, but no one says that if you do not do y you will not get x, however if you do not do y and not get the x it means that i keep my promise

Anonymous

Anonymous Thu 14 Apr 2022 16:57:39 No.14395050 Report

Quoted By:

>>14395041
I make dinner, promise to get Bass
After dinner, i get sad trombone
Blame instruments

Anonymous

Anonymous Thu 14 Apr 2022 17:01:59 No.14395057 Report

Quoted By: >>14395060

>>14394923
Normally, when we say that P implies Q, we mean there's a necessary logical connection between P and Q; but as you've discovered, that's simply not what the -> operator in boolean logic means, even though it's called "implication". It's actually just saying that "if P is true, then Q is true" always holds up if P is false, regardless of Q: either Q is true independently from P, or both Q and P are false, which is still consistent.

Anonymous

Anonymous Thu 14 Apr 2022 17:05:00 No.14395060 Report

Quoted By:

>>14394923
>>14395057
Another way to look at it is that "if P is true, then Q is true" is only demonstrably false when P is true but Q is not; in all other cases, it holds up.

Anonymous

Anonymous Thu 14 Apr 2022 17:05:51 No.14395062 Report

Quoted By: >>14395089 >>14395100

>>14395040
this is what I'm getting at now, but it seems like it will take a week for me to fully grasp what's happening

https://en.wikipedia.org/wiki/Material_conditional
https://en.wikipedia.org/wiki/Strict_conditional
https://en.wikipedia.org/wiki/Indicative_conditional
https://en.wikipedia.org/wiki/Paradoxes_of_material_implication
https://en.m.wikipedia.org/wiki/Counterfactual_conditional#Variably_strict_conditional

>>14395041
>i promise you that if you do y you get x, but no one says that if you do not do y you will not get x, however if you do not do y and not get the x it means that i keep my promise
ok that explains the last case (p F and q F), but if I don't do y but still get x, that says not doing y implied x, therefore your promise is still correct?

Anonymous

Anonymous Thu 14 Apr 2022 17:12:55 No.14395089 Report

Quoted By:

>>14395062
>therefore your promise is still correct?
yes because as i said, i only promise that i you do y you will get the x, i did not say that you cant get the x in other ways...
the only point of failure in my promise is if you do y but not get the x

Anonymous

Anonymous Thu 14 Apr 2022 17:16:08 No.14395100 Report

Quoted By: >>14395128 >>14396861 >>14400293

>>14395062
Don't bother trying to grasp it, or find some deeper meaning. It's just one of the divergences in language reasoning and mathematical reasoning. It's amusing to think about, but it just leads to the conclusion that definitions are important

Anonymous

Anonymous Thu 14 Apr 2022 17:24:22 No.14395128 Report

Quoted By: >>14400293

>>14395100
>Don't bother trying to grasp it, or find some deeper meaning. It's just one of the divergences in language reasoning and mathematical reasoning
There is a simple language-reasoning way to make sense of it: if I claim "when P is true, Q is true", no causal relationship is implied between the two; only that whenever P is true, Q is also true. That statement can only be false if P is true but Q is false. It's just named in a very unfortunate way that suggests a causal relationship.

Anonymous

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Anonymous Thu 14 Apr 2022 17:28:50 No.14395144 Report

Quoted By: >>14395209

>>14394923

Anonymous

Anonymous Thu 14 Apr 2022 17:43:38 No.14395174 Report

Quoted By:

>>14394923
formal logic is bullshit, dont overthink something thats wrongly objectivized by midwits and redditors

Anonymous

Anonymous Thu 14 Apr 2022 17:48:20 No.14395195 Report

Quoted By:

>>14394949
Were you in my discrete math class? Those are the exact same examples my teacher used

Anonymous

Anonymous Thu 14 Apr 2022 17:48:56 No.14395199 Report

Quoted By:

>>14394923

Propositional logic isn't the best way of understanding logic.

What you are really trying to say with this truth table is that (p) and (not q) are mutually exclusive statements.

The first line of the table translates to "p is true, therefore q is true."
The last line of the table translates to the contrapositive.

However, the second to last line is the difference between logical implication and a logical biconditional (in a logical biconditional, it is impossible for (not p) and (q) to coexist, but they will coexist in single directional logical implication).

This works in propositional logic because logical implication and logical biconditionals are distinct concepts, however, we don't use logic that way. We have an additional concept of "soundness," that is, we can still work with logical implication even if we don't know the entire truth table.

Anonymous

Anonymous Thu 14 Apr 2022 17:51:22 No.14395209 Report

Quoted By:

>>14395144
glowie mad that the CIA is no longer a chartered entity

Anonymous

Anonymous Thu 14 Apr 2022 17:52:36 No.14395211 Report

Quoted By: >>14400296

>>14395040
>that means the premise implies the conclusion
You're not evaluating if the premise implies the conclusion, you're evaluating if the entire statement is true. P->Q doesn't mean there's a causal link between P and Q. It just means that it isn't possible for P to be truth and Q to be false.

Here's a simple example. Let's say last Monday I told you:
>If it's sunny on Wednesday, then I will go jogging
Wednesday already came so one of the following happened:
>It was sunny and I went jogging
>It was sunny and I didn't go jogging
>It wasn't sunny and I went jogging
>It wasn't sunny and I didn't go jogging
Under which of those scenarios would you be able to say I lied to you?

Anonymous

Anonymous Thu 14 Apr 2022 17:55:00 No.14395216 Report

Quoted By:

>>14394923
If p is true, then q has to be true. But if p is false, q can be true or false, both are acceptable. Focus on the variable p and focus on its trueness.
I also had the same problem. Especially the third row of the table was very confusing to me.

Anonymous

Anonymous Thu 14 Apr 2022 17:58:31 No.14395226 Report

Quoted By:

>>14394923
=
or(not(p), q)
=
not( and(not(q), p) )

Anonymous

Anonymous Thu 14 Apr 2022 18:02:59 No.14395236 Report

Quoted By: >>14397105

Penquins and quarks = party
Penquins without quarks = lame
No peqnuins, only quarks = nice
No peqnnuus, no quarks = serenity

Anonymous

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Anonymous Thu 14 Apr 2022 18:30:49 No.14395305 Report

Quoted By: >>14395318

>>14394923
One way to eliminate the confusion is to consider the truthness of $P\rightarrow Q$ to mean "if we know $P$ then $Q$ is within possibility". If have no knowledge, then every speculation remains a possibility. If we gain knowledge, we realize that, knowing P, some of our speculations remain possible, while others become impossible.

Let's say $P$ symbolizes whether we know microbial life exists Europa and $Q$ symbolizes what we can say about that life.

Since we don't know whether life on Europa is microbial (i.e. P is false) all speculations about alien life are a possibility
>Q = "aliens have DNA" (possible, so P->Q is true)
>Q = "aliens are fish-like" (possible, so P->Q is true)
>Q = "aliens have a megastructure" (possible, so P->Q is true)

Now let's say we after sending a mission and we find out life on Europa is, in fact, microbial (P is true). Now only those speculations that can be possible for microbial life in particular may come into consideration as a possibility
>Q = "aliens have DNA" (possible for microbial life, so P->Q is true)
>Q = "aliens are fish-like" (not possible for microbial life, so P->Q is false)
>Q = "aliens have a megastructure" (not possible for microbial life, so P->Q is false)

If we send a probe and we don't find microbial life on Europa (P remains false) then those wild speculations about alien life must still remain a possibility.

In addition, let's say we prove life on Europa is microbial and you say we didn't (false premise). With a false premise, you may claim that all kind schizo theories about alien megastructure to be within the range of possibility, which makes P->Q true.

Finally, let's say you start from something nonsensical or unrelated to aliens such as "Traps are hot". Because this gave you no knowledge about whether life on Europa is microbial, every speculation about life on Europa remains a possibility, which also makes P->Q true for every Q.

Anonymous

Anonymous Thu 14 Apr 2022 18:35:13 No.14395318 Report

Quoted By: >>14396718

>>14395305
Hooooooly pseud bullshit. Imagine writing all this only to be so wrong.

Anonymous

Anonymous Thu 14 Apr 2022 18:37:13 No.14395322 Report

Quoted By: >>14395857

Reduce to CNF, it becomes (~p v q)

Anonymous

Anonymous Thu 14 Apr 2022 19:06:34 No.14395389 Report

Quoted By:

>>14394923
You can think of it like this:
All P -> Q states is that when P is true, Q is true. Nothing else. Thus, when P is false, P -> Q conveys no information about Q.
In those cases, is saying P implies Q false? Certainly not, because P -> Q doesn't say anything at all when P is false. Therefore it must be true.

See the following example:
P = you study
Q = you will pass the class
P -> Q : If you study, you will pass the class.
Now suppose P is false, you don't study, yet you manage to pass the class regardless.
Was P -> Q a lie?
Same if you don't pass the class and don't study.

Anonymous

Anonymous Thu 14 Apr 2022 19:12:14 No.14395404 Report

Quoted By:

>>14394923
A false premise does not imply the conclusion is true.
Just because p->q does not mean q->p. A false premise will only directly cause a false conclusion if you have something like
p->q
q->p
Or
~p->~q
Otherwise, the conclusion can still be true based on independent means.
If you have superpowers, you are a superhero.
Batman does not have superpowers.
Batman is a superhero.
As you can see, even though the premise of him having superpowers is false, its irrelevant because there was no premise stating "if you are a superhero, you have superpowers" or "if you do NOT have superpowers, you are not a superhero".

Anonymous

Anonymous Thu 14 Apr 2022 19:16:09 No.14395417 Report

Quoted By:

>>14394923
>the premise implies the conclusion
The premises (both) imply the conclusion

Anonymous

Anonymous Thu 14 Apr 2022 19:31:38 No.14395461 Report

Quoted By: >>14395492

>>14394947
Last two don't prove or disprove p-->q, is the default value supposed to be true?

Anonymous

Anonymous Thu 14 Apr 2022 19:37:52 No.14395470 Report

Quoted By:

>>14394923
the reason it's useful is you want the statement "A is a subset of B" to mean "for all x if x is in A then it is in B", which only works if vacuous conditionals are true

Anonymous

Anonymous Thu 14 Apr 2022 19:45:19 No.14395484 Report

Quoted By:

>>14394923
>i simply do not understand how if a premise is false and the conclusion is true, that means the premise implies the conclusion (meaning p-> q is true).
even if the premise is false and the conclusion true, the reasoning itself can be correct, so the implication is true

you can say something like
this dude carries an umbrella with him if it rains outside
so if p (it's raining) then q (dude's carrying an umbrella with him)
but he might be carrying that umbrella for some other reason, not just because it's raining, so it's possible that p is false while q is true
and the reasoning itself is correct, thus p->q is true

Anonymous

Anonymous Thu 14 Apr 2022 19:49:53 No.14395492 Report

Quoted By: >>14395509

>>14395461
Either you buy my product and get an improved erection, or you don't buy my product and get an improved erection, or you don't buy my product and don't get an improved erection. What's the problem with this statement?

Anonymous

Anonymous Thu 14 Apr 2022 20:04:09 No.14395509 Report

Quoted By: >>14395522

>>14395492
p-->q is an implication, if p doesn't happen p therefore q isn't really true or false. But it's fine, the --> operator could just be an implication with a true default value if the condition doesn't happen.

Anonymous

Anonymous Thu 14 Apr 2022 20:08:31 No.14395522 Report

Quoted By: >>14397171

>>14395509
Your post is barely comprehensible. Against, consider the statement in the previous post, which is equivalent to "you buy my product -> you get an improved erection", and suppose you don't buy the product; is the statement true or false, based on how 'and' and 'or' work?

Anonymous

Anonymous Thu 14 Apr 2022 20:14:03 No.14395532 Report

Quoted By:

>>14394923
This is only classical logic.
You probably want relevance logic.
There are many logics like linear logic and intuitionistic logics.
However, these logics are difficult to explain to beginners and have specialized use cases.
Probability can be viewed as a sort of logic.
As a formalist I don't personally believe in any one true logic.
If forced to pick I suppose I might want a cointuitionistic probabilistic modal logic.
A sample statement might be
"i have evidence it is not the case in 6% of worlds that the moon is made of cheese."
But this mostly seems like mental masturbation to me and classical logic is typically good enough.

Anonymous

Anonymous Thu 14 Apr 2022 20:21:04 No.14395560 Report

Quoted By:

>>14394923
Hey to get your money brains just think of it like Comp sci with
"And"
"Or"

Anonymous

Anonymous Thu 14 Apr 2022 21:53:07 No.14395857 Report

Quoted By: >>14395872

>>14395322
this, its just definition, no point trying to reason it.

Anonymous

Anonymous Thu 14 Apr 2022 21:58:30 No.14395872 Report

Quoted By: >>14396744

>>14395857
>no point trying to reason it.
Why are normalbots like this?

Anonymous

Anonymous Fri 15 Apr 2022 04:59:16 No.14396714 Report

Quoted By: >>14396718

>>14394923
I thought I got this, I mean I knew the table, I knew that I can remember it with just a single value (p and not q is false if p then q is true). But after doing many proofs I realized that as sets, p then q means that p is a subset of the events that occur when q occurs. Mind blown.

Anonymous

Anonymous Fri 15 Apr 2022 05:00:16 No.14396718 Report

Quoted By:

>>14395318
"within possibility" kek
and I just wrote quite the opposite here (>>14396714)
give me a star for not having mental retardation :)

Anonymous

Anonymous Fri 15 Apr 2022 05:15:10 No.14396744 Report

Quoted By: >>14397136

>>14395872
Discovering you were wrong hurts so they just cope believing that there could not possibly be anything more to it.
"If P then Q" and other logical statements are defined as they are, because they correlate with the usage of language. We didn't suddenly thought of defining this shit some way, it just happened with time as language evolved that we actually meant "p happens only when q has happened"

Anonymous

Anonymous Fri 15 Apr 2022 05:19:56 No.14396754 Report

Quoted By:

NOT SCIENCE
NOT MATH
>>>/out/

Anonymous

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Anonymous Fri 15 Apr 2022 05:22:39 No.14396760 Report

Quoted By:

>>14394923
It doesn't, you are not getting filtered, we just have midwits creating logic literature ;)

Anonymous

Anonymous Fri 15 Apr 2022 05:33:14 No.14396775 Report

Quoted By: >>14396809

It's vacuously true.

Anonymous

Anonymous Fri 15 Apr 2022 05:56:34 No.14396809 Report

Quoted By: >>14396812

Ignore the faggots saying to treat symbols as nothing more than symbols. They are not just symbols, intuition and rationality are highly intertwined with the symbolic representations and rules we create. Good math is about making things graspable by humans. People who see it as only symbols will never be good mathematicians.

This is the way to remember it: >>14396775
I think it helps to imagine we are quantifying over some domain: for all x, p(x)->q(x). if we take this as true, it means that p(x) is a sufficient condition for q(x) for any x. if p(x) is false for some x, it doesn't matter what q(x) is. p(x) is still a sufficient condition as long every time p(x) is true, q(x) is true.

Anonymous

Anonymous Fri 15 Apr 2022 05:58:14 No.14396812 Report

Quoted By: >>14396824

>>14396809
another possibility is considering that, if you are assuming p->q is true, but it turns out that p is false, you don't want it to restrict the possibilities for q. p is sufficient for q, but without p, q could still be anything, because p is not necessary for q. hence why p->q is vacuously true if p is false.

Anonymous

Anonymous Fri 15 Apr 2022 05:59:45 No.14396815 Report

Quoted By:

>>14394923
An implication is keeping a promise.
Think of it that way.

Anonymous

Anonymous Fri 15 Apr 2022 06:09:22 No.14396824 Report

Quoted By:

>>14396812
one more post from me because i think i am still overcomplicating it because its late

p->q simply means p is sufficient for q.

the wonkiness comes when you restrict yourself to thinking of only one universe/element of your domain for which p is false, because then you wonder how you can know if p is sufficient for q if p is false in the first place. however, if p were true, you still wouldn't know because you only have one case. this is why i brought up quantifiers. you have to consider all universes where p->q is true, or all elements in a universe where p->q is true, and check if p being true means q is true as well. in every universe where p->q, you know that p and q match one of the rows of your truth table where p->q is true. if in some universe where for all x, p(x)->q(x), you know that for every x, p(x) and q(x) match one of the rows in the truth table where p(x)->q(x) is true.

Anonymous

Anonymous Fri 15 Apr 2022 06:13:14 No.14396830 Report

Quoted By:

You are vermin -> im the king

Even if you wolndnt be a vermin, i m still a king

Anonymous

Anonymous Fri 15 Apr 2022 06:30:14 No.14396844 Report

Quoted By: >>14397100

F -> T:
-2=2 ->(-2)^2=2^2

F -> F:
2>5 -> 3>6

Anonymous

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Anonymous Fri 15 Apr 2022 06:47:26 No.14396861 Report

Quoted By:

>>14395100
>Don't bother trying to grasp it, or find some deeper meaning.
logical consequence is actually pretty involved
https://iep.utm.edu/logcon/
https://iep.utm.edu/logcon-m/
https://iep.utm.edu/deductive-theoretic-conceptions-of-logical-consequence/

Anonymous

Anonymous Fri 15 Apr 2022 06:59:50 No.14396866 Report

Quoted By:

>>14394947
/thread

Anonymous

Anonymous Fri 15 Apr 2022 10:21:04 No.14397100 Report

Quoted By: >>14397105

>>14396844
F -> T:
-2=2 ->(-2)^2=2^2
literally thats all you need

Anonymous

Anonymous Fri 15 Apr 2022 10:27:25 No.14397105 Report

Quoted By:

>>14397100
25-50-25 converted to 75-25
where 75% of True has different meanings
while 25% of false has A meaning
see >>14395236
party, nice and serenity = good
lame = bad

Anonymous

Anonymous Fri 15 Apr 2022 10:47:09 No.14397136 Report

Quoted By:

>>14396744
I wasn't wrong about anything. Unlike you and OP, I actually understand what the funny arrow means intuitively.

Anonymous

Anonymous Fri 15 Apr 2022 11:10:26 No.14397171 Report

Quoted By: >>14397183

>>14395522
It is specifically about the conditional p -> q.
So if you didn’t buy the pills it doesn’t matter what happens to your boner. It’s not applicable, and therefore under this conditional statement the result returns true no matter what. It’s about meeting the standards of the condition. When it doesn’t apply, then always true. That simple

Anonymous

Anonymous Fri 15 Apr 2022 11:17:41 No.14397183 Report

Quoted By: >>14397188

>>14397171
>It is specifically about the conditional p -> q.
I just spelled out for you what p -> q actually means, in a way that should be reasonably intuitive: p and q, or not p and q, or not p and not q.
It should be easy to see now why p -> q is true when p is false.

Anonymous

Anonymous Fri 15 Apr 2022 11:22:01 No.14397188 Report

Quoted By: >>14397196

>>14397183
I have no idea who you are in this thread but ok sure it is always true that not p will return true, no matter what q is, as I also stated. Congratulations you can also memorize not p or q and not p or not q as returning true

Anonymous

Anonymous Fri 15 Apr 2022 11:31:12 No.14397196 Report

Quoted By: >>14397199

>>14397188
>you can also memorize
And you can also understand what I just spelled out for you; then you don't need to memorize anything, because you understand how the funny arrow relates to, and differs from, "implication" in the regular sense. Then it becomes obviosu when the p->q is true and when it isn't.

Anonymous

Anonymous Fri 15 Apr 2022 11:33:11 No.14397199 Report

Quoted By: >>14397201

>>14397196
It’s very intuitive. That’s exactly what I’m saying, retard. I even applied it to the poor saps example

Anonymous

Anonymous Fri 15 Apr 2022 11:34:50 No.14397201 Report

Quoted By: >>14397204

>>14397199
You were driveling something about how "implication can be understood as implication with a default true value".

Anonymous

Anonymous Fri 15 Apr 2022 11:37:01 No.14397204 Report

Quoted By: >>14397209

>>14397201
>p and q, or not p and q, or not p and not q.
These are definitions though. I’m saying why it returns true, and it’s because no information can be gained if the condition isn’t met and so by default the result is true

Anonymous

Anonymous Fri 15 Apr 2022 11:41:55 No.14397209 Report

Quoted By: >>14397212

>>14397204
>These are definitions though
No, that's not a definition. That's a tautology that highlights what the funny arrow has to do with "implication", but also makes it easy to see why the entire statement is true when p is false.

OP's table is a definition.

>it’s because no information can be gained if the condition isn’t met and so by default the result is true
The ramblings of a 95 IQ lunatic.

Anonymous

Anonymous Fri 15 Apr 2022 11:42:51 No.14397212 Report

Quoted By: >>14397213

>>14397209
You are straight up gaslighting at this point or you are beyond help

Anonymous

Anonymous Fri 15 Apr 2022 11:43:33 No.14397213 Report

Quoted By: >>14397219

>>14397212
Legit 95 IQ.

Anonymous

Anonymous Fri 15 Apr 2022 11:47:10 No.14397219 Report

Quoted By: >>14397221

>>14397213
Notice how not p always return true. Why is that? Tell me without giving a definition of not p and q or not p and not q
Which happens to be the same as (not p or q).
…you’re retarded

Anonymous

Anonymous Fri 15 Apr 2022 11:49:33 No.14397221 Report

Quoted By: >>14397223

>>14397219
You are both low IQ and mentally ill. Just stop posting. Logic is not for you.

Anonymous

Anonymous Fri 15 Apr 2022 11:51:27 No.14397223 Report

Quoted By: >>14397236

>>14397221
This shit is so easy wtf are you talking about. Logic isn’t for you. Wtf?
This is extremely basic shit

Anonymous

Anonymous Fri 15 Apr 2022 11:54:10 No.14397236 Report

Quoted By: >>14397245

>>14397223
>This is extremely basic shit
Yes, and yet you are posting schizophrenic ramblings about how "no information can be gained if the condition isn’t met" and how tautologies are definitions.

Anonymous

Anonymous Fri 15 Apr 2022 11:59:00 No.14397244 Report

Quoted By: >>14400598

Here's the easiest way to look at it:
A true statement can imply a true statement
A false statement can imply a false statement
A false statement can imply a true statement
A true statement CANNOT imply a false statement
So the thing to focus on here is the validity of the implication itself.

Anonymous

Anonymous Fri 15 Apr 2022 11:59:37 No.14397245 Report

Quoted By: >>14397255

>>14397236
That’s not schizo that’s literally why it returns true

Anonymous

Anonymous Fri 15 Apr 2022 12:03:19 No.14397255 Report

Quoted By: >>14397257

>>14397245
Your schizophrenic ramblings have literally nothing to do with mathematical logic.

Anonymous

Anonymous Fri 15 Apr 2022 12:04:40 No.14397257 Report

Quoted By: >>14397260

>>14397255
Mathematicians are retarded. HOLY SHIT

Anonymous

Anonymous Fri 15 Apr 2022 12:06:10 No.14397260 Report

Quoted By: >>14397269

>>14397257
Knowing that p is false is all the information you need to know that p->q is true. "No information can be gained if the condition isn’t met" is a schizophrenic rambling that you will need to get past if you want to understand the subject.

Anonymous

Anonymous Fri 15 Apr 2022 12:09:20 No.14397269 Report

Quoted By: >>14397271

>>14397260
There’s a reason why p->q is true when p is false. The condition isn’t met. Therefore true. You can memorize it and call it tautological or you can understand why

Anonymous

Anonymous Fri 15 Apr 2022 12:11:25 No.14397271 Report

Quoted By: >>14397274

>>14397269
>There’s a reason why p->q is true when p is false
There is no reason for it beyond the truth table defining it that way. There is, however, a reason why such an operator exists, and why it's called "implication" -- something you're too stupid and mentally ill to even try to wrap your head around.

Anonymous

Anonymous Fri 15 Apr 2022 12:12:56 No.14397274 Report

Quoted By: >>14397275

>>14397271
An implication is a condition, RETARD ALERT HOLY SHIT

Anonymous

Anonymous Fri 15 Apr 2022 12:13:57 No.14397275 Report

Quoted By: >>14397277

>>14397274
You are mentally ill and low IQ. Please stop posting on this board. :)

Anonymous

Anonymous Fri 15 Apr 2022 12:15:13 No.14397277 Report

Quoted By: >>14397278

>>14397275
Fuck off faggot. This is my thread now. I hope I helped anyone and if someone has more questions I’m happy to help

Anonymous

Anonymous Fri 15 Apr 2022 12:15:47 No.14397278 Report

Quoted By: >>14397288

>>14397277
>I hope I helped anyone
You didn't. Your schizophrenic ramblings are incomprehensible, and have nothing to do with mathematical logic.

Anonymous

Anonymous Fri 15 Apr 2022 12:22:53 No.14397288 Report

Quoted By: >>14397290

>>14397278
Implication transcends mathematical definitions faggio
Learn the why or memorize it. Up to you

Anonymous

Anonymous Fri 15 Apr 2022 12:23:41 No.14397290 Report

Quoted By: >>14397298

>>14397288
>methematical definition transcends mathematical definitions
Mentally ill.

Anonymous

Anonymous Fri 15 Apr 2022 12:27:57 No.14397298 Report

Quoted By: >>14397302

>>14397290
You’ve never programmed in your life. Probably have never practically used implication in a logic system. You just know what the book tells you to memorize

Anonymous

Anonymous Fri 15 Apr 2022 12:29:06 No.14397302 Report

Quoted By: >>14397308

>>14397298
LOL. What a dumb subhuman. You will never be a programmer if you can't even grasp why I'm right and you're wrong.

Anonymous

Anonymous Fri 15 Apr 2022 12:31:52 No.14397308 Report

Quoted By: >>14397310

>>14397302
We are saying the same thing retard. You are giving a definition and calling it tautological. You can understand why but you refuse

Anonymous

Anonymous Fri 15 Apr 2022 12:32:39 No.14397310 Report

Quoted By: >>14397313

>>14397308
We're not. You're simply too subhuman to understand what I'm saying. lol

Anonymous

Anonymous Fri 15 Apr 2022 12:33:40 No.14397313 Report

Quoted By: >>14397315

>>14397310
>There is no reason for it beyond the truth table defining it that way.
This is what you said. Like a good little boy memorizing his tables

Anonymous

Anonymous Fri 15 Apr 2022 12:34:12 No.14397315 Report

Quoted By: >>14397318

>>14397313
You are mentally ill.

Anonymous

Anonymous Fri 15 Apr 2022 12:35:20 No.14397318 Report

Quoted By: >>14397321

>>14397315
Alright I’m done. Hope you had fun, I did

Anonymous

Anonymous Fri 15 Apr 2022 12:36:34 No.14397321 Report

Quoted By: >>14397326

>>14397318
You are one of countless mechanized subhumans whose "intellect" is limited to loose verbal games. You have no comprehension of the substance of the words you shart out. You are a dumber version of GPT-3.

Anonymous

Anonymous Fri 15 Apr 2022 12:39:16 No.14397326 Report

Quoted By: >>14397332

>>14397321
I think we can say clearly from this post, it’s you who doesn’t understand me.
I understand exactly what you’re saying and it’s about memorization

Anonymous

Anonymous Fri 15 Apr 2022 12:43:35 No.14397332 Report

Quoted By: >>14397341 >>14397346

>>14397326
>it’s you who doesn’t understand me.
There is nothing to understand about you. You're a mouth-breathing, label-thinking mongoloid:
>hurrr same label therefore same concept
No. The only connection between implication in the normal sense, and the implication operator in mathematical logic, is through that one tautology I've shown you, and it's a very loose connection. Your schizophrenic explanation attempts to tie the two distinct concepts together, and draw false conclusion about one based on the other, because you're a label-thinking bot.

>I understand exactly what you’re saying and it’s about memorization
Holy shit, imagine being mentally ill enough to write this.

Anonymous

Anonymous Fri 15 Apr 2022 12:50:45 No.14397341 Report

Quoted By: >>14397357

>>14397332
>There is no reason for it beyond the truth table defining it that way.
Remember you wrote this…
Your argument can be summed up as
>hurr durr i memowize it

Anonymous

Anonymous Fri 15 Apr 2022 12:53:19 No.14397346 Report

Quoted By: >>14397357

>>14397332
>draw false conclusion
Oh yeah? How is the conclusion false? I have the same conclusion as you

Anonymous

Anonymous Fri 15 Apr 2022 13:03:14 No.14397357 Report

Quoted By: >>14397373

>>14397341
>>14397346
LOL. This board is teeming with actual, clinical, low-grade imbeciles. p->q is true when p is false, because the truth table says so. There is not, and cannot, be any other reason for it. However, you don't have to memorize the table. I've already shown you have to understand intuitively what the -> operator means.

Anonymous

Anonymous Fri 15 Apr 2022 13:09:31 No.14397373 Report

Quoted By: >>14397374

>>14397357
If p then q
If not p then it doesn’t matter what the fuck q is
This is what I’m saying. How is my conclusion wrong?

Anonymous

Anonymous Fri 15 Apr 2022 13:10:43 No.14397374 Report

Quoted By: >>14397375

>>14397373
>How is my conclusion wrong?
>conclusion
Schizophrenic screeching about how "default values" and "not enough information" are not a conclusion.

Anonymous

Anonymous Fri 15 Apr 2022 13:11:40 No.14397375 Report

Quoted By: >>14397388

>>14397374
If not p then you don’t have the conditions to apply the operator and thus true. How is this wrong?

Anonymous

View Same Google iqdb SauceNAO 32524.png, 7KiB, 225x225

Anonymous Fri 15 Apr 2022 13:15:38 No.14397388 Report

Quoted By: >>14397389

>>14397375
>If not p then you don’t have the conditions to apply the operator
Holy mental illness...

Anonymous

Anonymous Fri 15 Apr 2022 13:16:57 No.14397389 Report

Quoted By: >>14397394

>>14397388
Please explain how it’s wrong?

Anonymous

Anonymous Fri 15 Apr 2022 13:18:24 No.14397393 Report

Quoted By:

paradox of material implication, simple as

Anonymous

Anonymous Fri 15 Apr 2022 13:18:37 No.14397394 Report

Quoted By: >>14397404

>>14397389
It's literally just schizophrenic word salad by a low IQ script kiddie who thinks mathematical operators are javascript operators.

Anonymous

Anonymous Fri 15 Apr 2022 13:24:59 No.14397404 Report

Quoted By: >>14397408

>>14397394
Ok so the answer then is because the truth table says so. Got it

Anonymous

Anonymous Fri 15 Apr 2022 13:27:45 No.14397408 Report

Quoted By: >>14397410

>>14397404
Yes. Why is that even hard for you to grasp? Anyway, mathematical operators are not javascript operators, dumb script kiddie. There aren't any "conditional actions" involved.

Anonymous

Anonymous Fri 15 Apr 2022 13:28:35 No.14397410 Report

Quoted By: >>14397412

>>14397408
Implication is conditional. Or how is it not?

Anonymous

Anonymous Fri 15 Apr 2022 13:30:03 No.14397412 Report

Quoted By: >>14397420

>>14397410
Do you see any "actions" and "conditions" in that truth table, mouth breather? No? It's just two values giving you a third?

Anonymous

Anonymous Fri 15 Apr 2022 13:33:10 No.14397420 Report

Quoted By: >>14397422

>>14397412
Yea I’m going back to thinking you’re retarded, sorry

Anonymous

Anonymous Fri 15 Apr 2022 13:34:31 No.14397422 Report

Quoted By: >>14397436

>>14397420
Do you understand yet that nothing is "applied" and nothing is "conditional" about it?

Anonymous

Anonymous Fri 15 Apr 2022 13:40:02 No.14397436 Report

Quoted By: >>14397439

>>14397422
This is math retard speak honestly
Technically I agree? But you really don’t see how it is applied and why true is returned?

Anonymous

Anonymous Fri 15 Apr 2022 13:41:52 No.14397439 Report

Quoted By:

>>14397436
Is 1+1=2 "conditionally applied"?
Why is f->t=t "conditionally applied" to you, retard?

Anonymous

Anonymous Fri 15 Apr 2022 22:36:54 No.14398580 Report

Quoted By:

>>14394923
If I piss onto my bed (p), then my bed sheets are wet (q).
p -> q
>I piss onto my bed and my bed sheets are wet.
So true. Well done, Chief.
>I piss onto my bed and my bed sheets are dry.
No way, nigger. Stop lying.
>I don't piss onto my bed and my bed sheets are dry.
Who let the dog onto my bed again? Go fuck yourselves.
>I don't piss onto my bed and my bed sheets are dry.
You know what? I believe you.

Anonymous

Anonymous Sat 16 Apr 2022 14:07:04 No.14400162 Report

Quoted By:

bump

Anonymous

View Same Google iqdb SauceNAO me rn no cap fr fr.png, 174KiB, 600x1221

Anonymous Sat 16 Apr 2022 15:12:05 No.14400293 Report

Quoted By: >>14400783

>>14395100
many logicians seem to think that way
https://en.wikipedia.org/wiki/Relevance_logic

>>14395128
>That statement can only be false
meaning P -> Q = F

>There is a simple language-reasoning way to make sense of it: if I claim "when P is true, Q is true", no causal relationship is implied between the two; only that whenever P is true, Q is also true
Meaning if P is false the claim P -> Q is true regardless because it only refers to the case where P is true?

Using better versions of the examples here
>>14394949

If all niggers commit crimes, and niggers will indeed be sent to Africa, P = T and Q = T, P -> Q = T. The promise/conditional is true.

If all niggers commit crimes, but they won't be sent to Africa, P = T and Q = F, P -> Q = F. The promise is false.

If not all niggers commit crimes, and niggers will be sent to Africa, P = F and Q = T, P -> Q = T because the promise is still (or could still be) true anyway.

If not all niggers commit crimes, and niggers will not be sent to Africa, P = F and Q = F, P -> Q = T because the promise (which is explicit that it's only talking about when P = T) is still true anyway.

>If all weebs like moe, then all weebs like shonen.

The promise/conditional is: When (all weebs like moe) is true, (all weebs like shonen) is true.

When P is F, whatever Q is will say nothing about the relation P -> Q.

This model seems to work well with future propositions, what about present propositions?

>If anon was born in Boston, then anon is american.

In your model this is equivalent to: When (anon was born in Boston) is true, (anon is american) is true.

For P = T it's trivial. For P = F, whether Q is T or F, it cannot prove or disprove the compound proposition (P -> Q) is T or F.

I

have

reached

enlightment.

But wait, why is P -> Q always T instead of always F (or just undefined) when P = F? Why assume it's T instead of F if, when P = F, nothing can be said about P -> Q?

Anonymous

View Same Google iqdb SauceNAO Wason_selection_task_cards.svg.png, 113KiB, 1920x678

Anonymous Sat 16 Apr 2022 15:13:11 No.14400296 Report

Quoted By: >>14400783

>>14395211
>Under which of those scenarios would you be able to say I lied to you?
Only the second, but only in the frist you told the truth, so why in the last two cases the truth table has you told the truth too? Seems more correct to say when P is false, P -> Q is undefined.

Your given explanation is the best one, at least for me, because it makes solving this problem very easy. You would be a good teacher.
>Each card has a number on one side and a patch of color on the other. Which card or cards must be turned over to test the idea that if a card shows an even number on one face, then its opposite face is red?

https://en.wikipedia.org/wiki/Wason_selection_task

I'm having trouble with p <-> q now, how would you explain it?

Anonymous

Anonymous Sat 16 Apr 2022 15:59:37 No.14400388 Report

Quoted By:

>everyone in this thread trying to justify something that is just plainly unintuitive.

I think the confusion comes about because we think of logical implication in common sense terms as a tool for arriving at a new conclusion, and such a tool has no practical use if the premise isnt true. So its like we are asked to consider if the tool reaches a conclusion when the whole context that would make it useful is not there. It just doesnt make sense.

OP, I think you should accept that propositional logic is not really the same kind of thing as practical every-day logic. Propositional logic states what is true or false. It isnt like an active form of reasoning where you churn through steps to discover if something is true or false, rather its a static description of the world, saying what can be true or false.

Logical implication in propositional logic is better thought of as a shorthand for "not P or Q". So in the FT and FF situations, "not P or Q" is clearly true, because in both cases P is false. Thats all there is to it.

I think this is even how the OG propositional logicians thought of things. They just defined a few operators (maybe not and or) and then defined all the rest in terms of the basic ones.

Anonymous

Anonymous Sat 16 Apr 2022 16:11:16 No.14400413 Report

Quoted By:

>>14394923
Assume 1=2. This is false. But if 1=2 then if we multiply by 2 we get 2=4. So 1=2 implies 2=4. Something false implies something false.
If 1=2 then adding one we get 2=3. Doing it again we get 3=4. So 1=2=3=4 etc. So far all natural numbers they are equal to 1. But 1=2. So all natural numbers are equal to 2. 2 is a prime number and there are infinitely many natural numbers. Thus there are infinitely many prime numbers. So 1=2 implies there are infinitely many prime numbers. The premise is false but the conclusion is true. Something false implies something true.

Anonymous

Anonymous Sat 16 Apr 2022 17:32:58 No.14400590 Report

Quoted By: >>14400601

>>14394923
It rains. I have an umbrella. I am dry.
It rains. I don't have an umbrella. I'm not dry.
It doesn't rain. I have an umbrella. I am dry.
It doesn't rain. I don't have an umbrella. I am dry.

That's how easy it is, literally can't make this shit up, 2022 /sci/.

Anonymous

Anonymous Sat 16 Apr 2022 17:36:31 No.14400598 Report

Quoted By:

>>14397244
That's just reformulating the OP picture without adding anything

Anonymous

Anonymous Sat 16 Apr 2022 17:39:03 No.14400601 Report

Quoted By:

>>14400590
Well done bro i only could make up penquins and quarks (which in itself was correct but translated into different meanings)
You did it 10/10

Anonymous

View Same Google iqdb SauceNAO 1645757979147.jpg, 79KiB, 819x1024

Anonymous Sat 16 Apr 2022 18:11:06 No.14400685 Report

Quoted By: >>14400783

>>14394923
>i simply do not understand how if a premise is false and the conclusion is true

Your confusion is understandable. The truth table for the implication does NOT state that the consequent is true if the premise is false. It states that IF the premise is false, then the whole conditional is true. This is a logically distinct claim the consequent is true. The consequent and the conditional are two very different entities, logically speaking. If P is false, then the entire implication P->Q is true, but the consequent Q is not necessarily true.

It helps to think of plausible real world scenarios in which you can see this sort of reasoning at work. In particular there is a fallacy I'm sure we've all encountered before: someone makes a conditional claim, stating that "IF X is true, then Y". Their opponent then replies with something like "well that's stupid because Y is false, so you must be incorrect." This is clearly fallacious, however, because the claim being made is not that Y is in fact true, but simply that IF X is true, then Y must also be true.

Anonymous

Anonymous Sat 16 Apr 2022 18:34:20 No.14400733 Report

Quoted By:

>>14394949
BASED and LOGICPILLED

Anonymous

Anonymous Sat 16 Apr 2022 18:39:45 No.14400747 Report

Quoted By:

>>14394923
$(P\to Q )\equiv (\neg P \vee Q)$ (this is in fact the definition).

Anonymous

Anonymous Sat 16 Apr 2022 18:52:52 No.14400783 Report

Quoted By: >>14400922

>>14400685
>It states that IF the premise is false, then the whole conditional is true.
I understand that now
>>14400293
>>14400296
but why does it say the conditional is true instead of undefined?

Anonymous

Anonymous Sat 16 Apr 2022 19:50:54 No.14400922 Report

Quoted By:

>>14400783
In the FT case, the conditional is true, but not _because_ of the antecedent. It just happens to be true.

I think you are reading too much causation into logical implication. Its whether "P implies Q" is true if P if false and Q is true, and them being true and false (respectively) is just how things happen to be, independent of each other.

Anonymous

View Same Google iqdb SauceNAO 1640645533569.gif, 1MiB, 320x198

Anonymous Sat 16 Apr 2022 20:01:27 No.14400947 Report

Quoted By:

>ITT: people mistakenly conflate P->Q with "P therefore Q".
The only connection between the two is this:
If "P therefore Q" is true, then either P and Q, or not P and not Q, or not P and Q; notice that this is statement is equivalent to P->Q, but the crucial thing is that the converse doesn't hold: "P and Q, or not P and not Q, or not P and Q" being true does NOT mean "P therefore Q" is true.

Anonymous

Anonymous Sun 17 Apr 2022 01:08:58 No.14401529 Report

Quoted By:

>>14394923
>implying

Anonymous

Anonymous Sun 17 Apr 2022 04:13:25 No.14401932 Report

Quoted By: >>14401941 >>14401945

>>14394923
I don't understand this until I use NixOS
it is being used as a dependency, meaning that if p is true then q has to be true as well
for example in w3m, there's this line
`assert sslSupport -> openssl != null;`
it means that if ssl support is enabled then you must provide openssl
if p is false, then the program will not care about q, whatever q might be

Anonymous

Anonymous Sun 17 Apr 2022 04:20:16 No.14401941 Report

Quoted By: >>14401965

>>14401932
interesting, I like applied examples

would something like

not assert sslSupport or openssl

work the same? because in theory the truth table is the same, meaning

p -> q <-> ~p v q

Anonymous

Anonymous Sun 17 Apr 2022 04:23:10 No.14401945 Report

Quoted By: >>14401967

>>14401932
it's kind of confusing though since don't pointers use the same symbol?

Anonymous

Anonymous Sun 17 Apr 2022 04:25:02 No.14401946 Report

Quoted By:

Imagine if your parents say "If you behave you will get ice cream"
One day, you behave, and you get ice cream.
The next day, you behave, but get no ice cream.
The next day, you misbehave, and get ice cream anyway.
And the next day, you misbehave and get no ice cream.
Out of the four days, on which day did your parents lie to you?

Of course, it would be a little different if your parents said "You get ice cream if and only if you behave", that would make the third day into a lie.

Anonymous

Anonymous Sun 17 Apr 2022 04:34:59 No.14401965 Report

Quoted By:

>>14401941
yeah

Anonymous

Anonymous Sun 17 Apr 2022 04:38:36 No.14401967 Report

Quoted By: >>14402043

>>14401945
what pointers?

Anonymous

Anonymous Sun 17 Apr 2022 05:24:40 No.14402043 Report

Quoted By: >>14402047

>>14401967
https://www.tutorialspoint.com/cprogramming/c_pointers.htm

Anonymous

Anonymous Sun 17 Apr 2022 05:26:56 No.14402047 Report

Quoted By:

>>14402043
Nix language isn't C
it's not even imperative, it's functional

Anonymous

Anonymous Sun 17 Apr 2022 05:46:33 No.14402104 Report

Quoted By:

Lies are truth and truth is a lie.

If you make false premises you can never be wrong

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