Is this rule bi-conditional?

Tina Cho

Hi
So on LG I meet this kind of rule sometimes

A---B→C---D "If A is before B, then C is before D"
Is this actually bi-conditional in sinmple sequence game?
For grouping sequence game, it may not be necessary true, but for simple sequece game there is only either before or after something, so...

By the way we cannot delete our threads right?
I wonder what if we solve the question before get any replies...do not want to bother other ppl in that case

BinghamtonDave

No. As written, the rule is not biconditional. If C is before D, the rule tells us nothing about the placement of A and B. Lets look into this a bit deeper as it would apply to a sequencing game: lets pretend we have 4 spots. Numbered 1-4. Let make A before B. That forces C before D.
In each of the below instances we have the fulfillment of the sufficient condition:


Now lets fulfill the necessary condition as the rule is written, that means we put C before



Here we have a valid arrangement in which C is before D yet B is before A. This would not be a valid arrangement if this was a biconditional. In a true biconditional, if C was before D, the worlds above the black line would not be valid.


Our final point here is that the rule as written lacks the traditional biconditional language. Something like A is before B if and only if C is before D. Take that "If and only if" apart and you have 2 conditionals. If signifying sufficient and "only if" signifying necessity.

Tina Cho

@BinghamtonDave
Ah, I see! Thank you a lot Dave

Alex

@BinghamtonDave coming in clutch with the written out explanation! You Da man!