In and out Games and Biconditional rules

[Ellesat]

I have a question about biconditional rules for in and out games. I'm not sure how to put it into context, but let me try using this game:

PT48, G1
I see someone asked a similar question in the past but it wasn't noticed or answered and I'd like to ask myself - why don't we write the first rules as a biconditional e.g. H<->/R, instead of a regular conditional H-> /R? They both have to go into one group or the other, and if one is used the other cannot be used and vice versa? They can never be used together so I did biconditional. Any help would be appreciated

just realized both of them can be out, is that why they aren't biconditional?

[ohthatpatrick]

Exactly.

When we see a rule like
H --> ~R
R --> ~H

our brain wants to think of that as "they're mutually exclusive! one is IN and one is OUT"

But that's wrong. The rule is just saying "they can't both be IN", which means they CAN still both be OUT.

For this type of rule, since "they can't both be IN", we know that "at least one is OUT", so many of us put a
R/H+ placeholder in the OUT column,
telling our brain, "The OUT column requires that at least one of these fools is always there."

[Ellesat]

thank you Patrick, your explanations have helped me so much. usually they start with "if __ then" and I don't know I guess this way of stating the rule made me think biconditional. I didn't think it through. Thanks!