Sorry for the inane post but I could really use some clarification

>>8203755
true
april showers characterize may flowers
as in, one happens if and only if the other one does

false

can't you just contrapose the first statement to deduce 17 must be true?

they probably wanted you to see that 17 is only possible based on statement 2 because they're stupid

>>8203785
Contrapositive of the first + the 2nd gives the equivalence

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>>8203801
Wrong Jane you ignorant slut.
Causality does NOT imply exclusive causality.
The temperature could have been too cold.

False, in that the statement does not hold true from the premises given.

the book probably said false, but yeah I think the book is wrong this time.
even if there is another factor than can cause the flowers not to bloom, it doesnt matter as they will never bloom when there is no rain.
It's just a badly worded statement really, the "only" being the major problem.

>>8203810
if you're sitting in may with no flowers then how could it have possibly rained in april?

>>8203815
on second thoughts I can see why he thought it's false as there can exist another reason for the flowers not blooming, even if that reason is equivalent to the rain.

OP here: book said "merely possible."

my take is that they're asking if it's possible for the set of april showers to intersect the complement of the set of may flowers, but based on the first statement, we have april showers as a subset of may flowers

>>8203765
I can prove it's false.

April showers = p
May flowers = q

first sentence is:
p => q

second sentence is:
not p => not q

now check if those two things are equivalent (they are not).

and as >>8203824 said, there can be another reason why flowers aren't blooming. for example, bee population completely gone or nuclear bomb. it's just a coincidence that it didn't rain that month then since no flowers could have bloomed anyway.

>>8203830
but the premise is that the first and second statements must always be satisfied, the only way that's possible is if p is equivalent to q

>>8203830
>>8203832
aka p=>q ^ q=> p == p<=>q

>>8203755
False, because it is not a reason, let alone the only reason.

>>8203832
and that would be equivalent if p => q and q => p
the statements aren't set up that way though.
implication isn't commutative.

>>8203837
don't mind me, I can't read for shit.

>>8203837
>>8203830
>>8203801
statement 1: AS => MF
contrapose: ~MF => ~AS
premise of 17: ~MF == TRUE
this means TRUE => ~AS
ergo: ~AS must equal TRUE or the implication fails

>>8203830
>when it rains, flowers bloom
>when it doesn't rain, flowers do not bloom

How else would you describe an exclusive condition?

>>8203838

jesus are you all fucking trolls

statement 1: p=>q
statement 2: ~p=>~q
contrapose statement 2: q=>p

>>8203828
So the book presents you with that passage about rain, asks about rain, but the answer is based on other, outside possibilities that don't involve rain?
Yeah, it's 'merely possible' if you take into account other things like soil, the possibility of someone else watering the flowers, etc. But that's thinking outside the box bullshit.

>>8203830
you make zero fucking sense

>>8203849
no other factors can possibly matter based on the statements... the only possibility would be something like april showers happening, may flowers blooming, and then someone coming along and plucking all the flowers after they bloomed so they're not there anymore... yet why the fuck should someone consider that possibility

>>8203848
may flowers do not bring april showers

>>8203851
what makes no sense?

>>8203855
Exactly. The only factors that matter are the ones presented to you. And the only thing given to you is:
>if it rains, flowers bloom. if it doesn't they don't.
So a 'possible' answer to that, taking only the rain into consideration, is wrong, and so is the book.

>>8203856
"the implications say different things so anything goes"

False. The only things you can know from the statements are
1. if there are april showers, then there are may flowers
2. if there arent may flowers, then there arent april showers
3. if there arent april showers, then there arent may flowers
4 if there are may flowers, then there must've been april showers

None of these statements speak to other causes of a lack of may flowers.

>>8203785
the contrapositive of the first statement is that if there aren't may flowers, then there werent april showers (which doesn't imply anything about why may flowers may not bloom)

>>8203856
so we're not allowed to contrapose implications?

>>8203871
>>8203830
and anyone else thinking false:

it seems like the only basis for your arguments is that formal logic cannot and therefore should not be applied to this task.. is this true?

>>8203828
can someone please try to refute this?? nothing any of the falsers claim has spoken to this

>>8203877
Yes. You can't make a statement like "there exists no other cause" because that's simply something you can't know. It may seem trivial because the statements do bind april showers to may flowers, but it doesn't speak at all to the general set of possibilities. The statement "there exists no other cause" however, does speak to the general set of possibilities (but you don't know about the whole set).

Unsure if you're doing this as part of a computer science curriculum or not, but on a side note the importance of distinguishing between what you do and don't know in a whole set becomes really important in a lot of fundamental theory.

>>8203877
conversion error

>>8203886
*converse error, sorry. not my native language.

>>8203877
https://en.wikipedia.org/wiki/Affirming_the_consequent

>>8203882
it just kinda sounds like you're arguing for the possibility of divine intervention obstructing the implications.. is that what they teach comp sci students?

>>8203894
holy fucking shit seriously go fuck yourself

>>8203849
>Yeah, it's 'merely possible' if you take into account other things like soil, the possibility of someone else watering the flowers, etc. But that's thinking outside the box bullshit.

It's literally not wrong though. Like it's not a matter of thinking outside the box, it's a matter of understanding axioms and sets. There's a universal set of possible causes and none of these statements speak to april showers being the only cause of may flowers, it's simply wrong to suggest that's the case.
>>8203881
Falser here

April showers are indeed a subset of May flowers. Accordingly, you can't claim that a lack of april rain is the only reason may flowers dont bloom (if that was the case may flowers would be a subset of april showers).

It is merely possible because while the two are biconditionally related the statement in question 17 is making claims about other causes that haven't been written about in the premises (i.e. "the only reason" can be interpreted as excluding every other possible cause in the set of all causes). It's possible, because we don't know anything about the other possible causes (i.e. whether they do or don't cause flowers to bloom)

>>8203894
it would be p=>q; ~q, therfore ~p, which is valid by the implication

>>8203902
the complement of may flowers IS a subset of the complement of april showers

>>8203902
based on statement 2 may flowers is indeed a subset of april showers (:

>>8203898
Nope, it's called abstraction. OP is looking at formal logic. None of the premises speak about the set of all possible causes, however question 17 does make a claim about all possible causes. That's simply unwarranted.

Think of it this way:
Suppose the set of all possible considerations is as follows: U={A,B,C}

If I tell you

1. if B then C, and
2. if C then B,

can you conclude that if A then C is untrue? Of course not. I never said anything about A. This is the same situation

>>8203898
Oh by the way, here's the relevance in computer science if you're interested

https://www.wikiwand.com/en/Halting_problem

>>8203902
what you're literally saying is that if the soil is bad, and this means there are no may flowers, then this would have to also mean that there were no april showers, i.e. bad soil implies no april showers... is this seriously a valid conclusion in your mind

>>8203904
no it would be p=>q; ~p, therefore ~q. which isn't valid by truth tables.

>>8203913
"A is the only reason for B" == "B only if A" == B=>A which is equivalent to the contraposition of statement 2

>>8203916
It's a logical conclusion. Sure bad soil implies no april showers, but does it imply that bad soil wasn't the cause of the lack of may flowers? Of course not. It's possible to have multiple causes in this scenario.

>>8203926
statement 1****

True. Rains ALWAYS cause flowers, all other factors don't matter, lack of rains causes lack of flowers. So yes, lack of rains is the only reason for lack of flowers, because if there were rains, there would be flowers.

>>8203926
B only if A simply implies that if C causes B, then C must also cause A. However, it doesn't speak to whether or not C actually can or can't cause B.

See this post:
>>8203927

>>8203927
how can the state of the soil imply anything about the weather.... unless they are all equivalent in which case this whole argument is completely arbitrary because why would we just assume the possible existence of another equivalent condition and then say "no this new assumed equivalent condition is the actual reason"

>>8203932
>all other factors don't matter
all factors do matter if you're making a claim about all factors. Yes, a lack of may flowers will always be accompanied by a lack of april showers, but you still don't know anything about other causes (q17 is making the claim that ALL these other non-shower related causes cannot cause a lack of may flowers, which we simply can't conclude).

>>8203830
what the fuck are you talking about
with these two
p => q
not p => not q
you have fucking equivalence, p <=> q
if there's any reason there aren't may flowers, it's equivalent to there not being april showers

>>8203810
If there are other possible causes of "no flowers", then it must be possible for it to rain and to not have any flowers, because no rain isn't the only cause no flowers.
That contradicts the statements.

>>8203938
are you saying that there could be a subset of april showers that, if true, would create the domino effect as the original "cause"? because then I actually may be on board...

>>8203937
In your previous post you said
>what you're literally saying is that if the soil is bad

If we're going with this assumption then we can make assumptions about the weather (as the soil being bad -> no may flowers and no may flowers -> no showers)

The textbook said "possibly" because we don't actually know anything about soil and what it does.
The point is that although may flowers and april showers go together, q17 is making a statement that every other cause that isn't april showers can't cause may flowers. That's simply unknowable, as we know nothing of the other causes.

>>8203940

See this: >>8203927
>>8203945

The biconditional only implies that if there are no may flowers there are no april showers, it doesn't speak to other causes and how they relate to a lack of may flowers however.

>>8203944
Yup exactly that. It doesn't matter if april showers will always accompany may flowers, what matters is that other stuff can cause it too (potentially)

>>8203945
you literally just said that lack of flowers in may can retroactively prevent rain from happening in april....

>>8203951
i still think it's bullshit to be expected to assume a possible cause of april showers as the genesis of the problem and therefore the legitimate "cause" but whatever fuck me i guess

>>8203957
A lack of may flowers does imply a lack of rain (contrapositive of statement one)

>>8203960
It's not because a big part of logic is understanding what you can and can't conclude from the given statements. q17 is a super broad statement, it's literally saying that NOTHING can cause a lack of may flowers, which is pretty crazy cause it's saying literally everything but april showers is unrelated to may flowers. Unless it used the word "only" somewhere we can't make such broad claims about a universal set.

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>>8203940
that's an inverse fallacy.

p = it's snowing
q = it's cold

if it's snowing, then it's cold (p => q)
it's not snowing (not p).
therefore it's not cold (not q) (this statement is bad because it can be cold without snow).

>>8203948
In other words if we do not assume the premises to be true when it's true, the premises have become circumstantial.

>>8203963
yes but he's saying the lack of may flowers itself was already caused by SOMETHING ELSE and THEN makes it so there are no april showers, which were NOT the cause of the no may flowers

>>8203974
In the problem it is given:
p => q is True
AND
~p => ~q is True

What you're saying is:
p => q is True
~p is True

>>8203974
there are two inverse statements given fuckhead, inform yourself of the situation before you make idiotic posts

>>8203974
>that's an inverse fallacy
no it's fucking not
~p => ~q is equivalent to q => p
that, along with p =>q, gives you q <=>p

>>8203975
Nono the premises are true. Like, we're assuming the premises are 100% true. It's just that none of the premises talk about "everything else", but q17 does make a claim about "everything else" (i.e. "everything else" isn't a cause of a lack of may flowers). q17 is a statement made totally out of the scope of the premises. Yes you can conclude that whenever there are no may flowers there are no april showers, but you can't conclude that nothing else can cause no may flowers. (because nothing else=everything else=stuff not addressed in the premises).

>>8203978
Yup, which is fine. The linearity of events doesn't matter. What matters is that you can conclude IF there are no may showers, then there mustn't have been april showers. Sure, you can say "those lack of april showers caused the lack of may flowers" but it's also totally possible that some external event caused a lack of april showers which in turn caused a lack of may flowers (and so you can say that if that external event occurred, it would cause a lack of may flowers).

>>8203990
that's not what the guy said at all but it is what i already said in an earlier post so thanks genius

>>8203990
but the way you phrased that still labels april showers as the cause of no may flowers specifically, and the question doesn't ask for the cause of the april showers so...

I have a ball.
If I hold the ball, it will stay in my hand.
If I do not hold the ball, it will not stay in my hand.
I did not hold the ball.

Is it true that my not holding the ball was the only reason it didn't stay in my hand?

>>8203990
>and so you can say that if that external event occurred, it would cause a lack of may flowers).
But only through lack of showers. Direct reason for lack of flowers is always lack of showers.

>>8203991
That's exactly what I said (I've been the same person replying to you this entire time btw).

I said
> (as the soil being bad -> no may flowers and no may flowers -> no showers)

Which isn't wrong (no may flowers implies no showers).

>>8203995
The statement in q17 doesn't say "april showers don't cause may flowers", it said "there is NOTHING else that causes may flowers". Which is unknowable.

If I have these 3 statements:
1. If A then B (A->B)
2. If B then C (B->C)
I can very simply conclude that If A then C. Right? It's one of those elementary logic examples they use when introducing this stuff. This conclusion says that A is a cause of C, even if indirectly. Q17 would posit that because B->C and C->B then A->C is untrue, but of course thats unknowable (it didn't make any statements about A).

>>8203997
>>8203997
Sure, but that doesn't deny that the external event was a cause. Q17 isn't saying april showers arent the cause of may flowers, it's saying that the external event couldn't have caused the may flowers.

See: >>8204005