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@dromadery_camel66
The reason you can remove one condition is because one being true makes the other false. Invalid by contradiction, because for 'And' statements, conditions can't disqualify one another (both/all must be able to exist together).
And two conditions aren't compatible for existence, because if you like the intrinsic qualities, you're not only liking the value of investment. The other way to think about this--if one is only thinking of investment value, they can't also be thinking about intrinsic qualities.
What helped my thinking most: when scanning the answers, none stated 'does not care about intrinsic values'. They only implied 'cares about value' but caring about value does not mean value is the only thing cared for, nor that intrinsic qualities aren't cared for.
what would trigger the value rule? (it can still be triggered)
"Matilde only cares about the art piece's value as an investment".
Since investment value is the only care, intrinsic qualities cannot be a care too, therefore, Matilde should not buy the vase.
Notice how if one rule is true, the other cannot be. For conjunctive 'And' statements, if one condition fails, the statement cannot be true. Both conditions must be met (or both not met).
Hope that helps. Best.
@pbahoura You got it ! The order isn't so important here since both options are saying the same thing just flipped. Helps me to think about this as an "OR operation".
A or H
-A
Therefore H
Or,
A or H
-H
Therefore A
If August -> Not holiday
A -> -H
If holiday -> Not August
H -> -A
helpful rewrite from:
Students are late only if they arrive more than five minutes after the bell.
TO
Only if students arrive more than five minutes after the last bell can they be late.
@juliairelandd
The first is a set and grouping question. Think of it as groups inside groups. Banana is inside (an element) of the fruit set. So are grapes, apples, and tomatoes.
Set of fruit: {banana, grapes, apples, and tomatoes}
Now, in an argument, we can now make rules for those items (elements) in the set of fruit.
For example, Rule: “all Fruit are from seeds.” This rule is placed on the entire collection of fruit inside the set of fruit. It applies to apples since apple was stated as an element of our fruit set.
Therefore since all fruit are from seeds, and apples is a fruit, then apples must be from seeds.
In fact, by saying “all Fruit”, we’re saying, for something to be a fruit, it’s necessary to have came from a seed. If something has not come from a seed it cannot be a fruit since all fruits come from seeds.
however, if something came from a seed that does not mean it must be a fruit.
the first argument is saying if x is apart of this set or group, then x must be “this”.
The second argument is saying if x occurs, x creates y, and if y exists, Z must follow. (It’s a casual inference chain argument, not an argument involving groups).
Both have the same exact argument structure.
Argument 1
where A = cat, B = mammal
all “cats” are “mammals” (A -> B)
X is a cat (x is A, and remember all As are Bs).
Therefore, x is a mammal. (Since x is A and all A->B, x must also be B)
Argument 2
Let A = more restaurants open, B = improved living standard.
If more restaurants open then improved living standards. (A -> B).
More restaurants opened. (x = A, A = True -> B must also be True).
Living standards improve. (therefore B must have resulted, since A -> B).
Notice how argument 1 uses groups and rules/qualities about those groups (If under18 -> minor. X is under18, therefore X is minor).
While argument 2 uses causal reasoning. (If it’s winter time there’s less food, and it’s winter time, so therefore there’s less food.)
“Less food” is an amount, not a clear grouping like “fruit”. This is the reason why the second argument does not get translated like the first argument. “Increases, decreases, improves.” These are verbs of unspecified change, not nouns “Apple” or “fruit”.
what’s most important is that these two arguments produce the same logical structure despite one containing sets and groups, while the other contains A casual inference chain .
If A -> B
A
Therefore, B. Same structure.
Hope that helped.
If you want to dive more deep into valid arguments and proofs. The book, “How To Prove It”, is a cool book on the subject.
It’s 2nd chapter is especially useful as you learn about (and ^) and (or) notation, which comes with drills. the drills have you turn sentences like:
“if it does not rain tommorow then it will snow” into logical structure.
Where R = rain, S = snow.
-R —> S (if NOT rain then snow).
It will either rain or snow. (R OR S)
-S
therefore R.
At minimum I’d hammer home DeMorgan’s Law:
P —> Q
-Q —> -P (valid)
-P —> -Q(invalid)
For AND^ operations:
(P ^ R) —> Q) if P and R then Q
-(P ^ R) —> -Q) if not P and R not Q
(-P OR -R) —> -Q) (OR flips ^ down)
if not P nor R not Q
@Matt.bartos if one’s not cooked one doesn’t call others cooked.
If one’s cooked one calls others cooked.
“If you find this confusing ur cooked lol”
—Matt.bartos
fat cats who sing the blues
Cats who sing the blues
Cats who sing
Cats
If Garfield is a fat cat who sings the blues, then we know he’s a cat who sings.
If Garfield is a cat, we don’t know if he sings.
First-year Harvard law students
Harvard law students
Law students
Students
This was a very hard problem.
Clicked when I considered: The worms either came prior to the ferns disappearing, or the worms came after.
If the worms came after the ferns were already gone, the conclusion is false. They did not cause the fern to go poof since they’re already gone.
So that’s the gap. The worms must be attracted to the trees prior to ‘vanishing’, not the habitat once vanished. Which E satisfies.
That reasoning chain only came clear after answering the question.
Me agree.
wrote book. Book okay.
Next book better.
But write story not argument so argument different. Since argument grammar not story grammar. Me relearn like book for argument.
I study English for 5 years. Degree mine. If not obvious. Hard to be like me and me master.
@Dom80 i feel the purpose is pretty clear.
Break up the sentnance so it’s more clear to understand.
But we did already do that and that, the word, is not super distinct here.
Yet the repetition of trying to make the language understandable as clear and quickly as possible has helped me.
Break grammar. It’s Not required for clarity. Yet grammar required for precision. LSAT writers love grammar. Not because it’s proper, but because it can hide the meaning.
Who has to find it. Not them.
Instead of seeing large chunks of words, I'm starting to see the barebones. A lot of words can be skipped which could not be skipped prior to seeing these barebones outline. Makes it a a lot faster to parse what's being said.
Instead Chunks [words or x] I start to see [barebones or y]
Evidence: Skip more chunks of words than before; what changed: argument structures were unknown and now known.
conclusion: understanding argument structure made y possible, and doing y has made it Faster to parse what's said than [chunks of words] x].
BONES: skipping words helps parsing. Why? there's less needed to be read to understand. How did skipping more words become possible? Understanding Arg structure...Arg structure is only possible if one studies...
one can only study if they care...
care - study - understand arg structure - read less word fluff - parse questions faster...
C -> S -> Uarg -> RDL -> PQF ->....