Biconditionals vs regular rules?

abella123

Hey all, I'm aiming on nailing the logic games concepts so deeply in my head that they become easy to me, so I'll be consistently posting on this forum with plenty of questions up until my February testing. I apologize in advance.

My question concerns the biconditionals. I am taking this example from PT26 S1G4.

Here it says "G and V do not serve on the panel in the same year" which translates to G --> /V and V --> /G (contrapositive)

Then another rule says "Either I or V serve on the panel, but not both" which translates to I --> /V and V --> /I also shown in double arrows I <--> /V.

One of them, the I and V rule was called a biconditional by the instructor which I understand as it meaning the the presence of one confirms the absence of the other...But now I'm wondering what is the difference between the first and second rule. Because right now they look the same to me, but I know there is an inherent concept. I already understand the difference between both and but not both, but I'm a little confused here - anything would be helpful.

Thank you

goingfor99th

G <--|--> V
I or V bnb

The first rule says they can't both be in; they may both still be out. The second rule says one must be in but that they can't both be in/out together.

abella123

@goingfor99th said:
G <--|--> V
I or V bnb

The first rule says they can't both be in; they may both still be out. The second rule says one must be in but that they can't both be in/out together.

That was very straightforward, I get it now. Thank you so much! x

goingfor99th

@aciss038 said:

@goingfor99th said:
G <--|--> V
I or V bnb

The first rule says they can't both be in; they may both still be out. The second rule says one must be in but that they can't both be in/out together.

That was very straightforward, I get it now. Thank you so much! x

No problem.