If you need LR help...

[TheCanadian]

Feel free to ask away. I'll try to help explain why the answer is wrong/right and guide you through the reasoning as best as I can. This is good practise for both you and me.

[umass22]

If something says "A only if B" you always map it as "A----B"? So the "only if" signals a necessary clause, and the other thing is the sufficient?

[TheCanadian]

If something says "A only if B" you always map it as "A----B"? So the "only if" signals a necessary clause, and the other thing is the sufficient?

exactly.
The a phenomena can only occur with the presence of b. B is that necessary clause.

[n/a]

A only if B...

If A occurs, then B must have occured as well

B can occur and still not mean A happened.

It rains only if its cloudy.

If its cloudy, its not necessarily raining, but if its raining, then its cloudy... ya see?

[TheCanadian]

A only if B...

If A occurs, then B must have occured as well

B can occur and still not mean A happened.

It rains only if its cloudy.

If its cloudy, its not necessarily raining, but if its raining, then its cloudy... ya see?

haha precisely...let's reiterate it some more...it's kinda fun.