The only way that bookstores can profitably sell books at below-market prices is to get the books at a discount from ...
jbenav246@gmail.comJanuary 8, 2021
Rewriting logical sentences
In the prompt, it lists the N before the S: "Unless bookstores generate a high sales volume, however, they cannot get discounts from publishers."
I drew this out as N -> not S
but on the video explanation, he drew it
S -> N
So my question is, I can understand if you reverse the ordering for the S/N to make it easier to read, but why did he take away the negated aspect of S? Should it not be:
not S -> N
Replies
Create a free account to read and
take part in forum discussions.
I'm not an instructor but what I understood is that it says unless meaning ( not N --> not S), so the counter positive is S --> N
What I do is put the necessary in its place first since it is given first and then analyze the sentence to make sense.
--> N
and then put in the sufficient
S --> N
shunheJanuary 13, 2021
Hi @jbenav246@gmail.com,
Thanks for the question! So the correct way to diagram the statement “X unless Y” is
~X —> Y
Or its contrapositive,
~Y —> X
So you can think of “unless” as introducing the necessary, and then you put the rest in the sufficient, but you have to remember to negate it. Or you can think of unless as “if not,” or in other words, introducing the negation of the sufficient.
Here, however, there’s already a negative in what we want to diagram. Remember, the sentence is “unless bookstores generate a high sales volume, they can’t get discounts from publishers.” So
X = can’t get discounts from publishers Y = generate a high sales volume
So we diagram it
~(can’t get discounts from publishers) —> generate a high sales volume
And double negatives make a positive. So “not cannot” is just “can.” So it gets diagrammed as ?Discounts from publishers —> Generate a high sales volume
Hope this helps! Feel free to ask any other questions that you might have.
