Lesson 2, page 18: Double Arrow: "If But Only If"

[concrottrox11@gmail.com]

What does the phrase mean "if but only if" operates in the same way, as does just reversing a conditional statement?"

Can you please give an example of using both "if but only if" and what you mean by "reversing a conditional statement?"

Thank you!

[Dave Killoran]

Hi C,

The "if and only" model, which includes variants such as "if but only if," "when and only when," "when but only when," etc is awesome because it produces a very simple relationship: a double arrow, or .

Under a double arrow, each condition is both sufficient AND necessary for the other. That's tough to understand at first, so it more easily can be understood as : they both need each other

So, if you have A B, it means only the following two scenarios are possible:

1. A and B both occur.
2. Neither A nor B occurs.

That's it. What's impossible is one happening and the other not happening. Here's more on it: https://blog.powerscore.com/lsat/bid-26 ... questions/

Thanks!