Consider this chain:
A —> B—> /C or /D
I understand Demorgan's Law Regarding Contrapositives. But how do we work with the 'possible worlds' this chain represents?, particularly w/r/t moving backwards along this chain.
I believe it means 'If B, then "C not D, or D not C, or Not C not D.'. If that's correct, my next question is what would require triggering the negation of B?
If I'm presented in an AC with "Assume D", can I negate B?
In my mind, negating B requires BOTH Not C and Not D. Is that incorrect?
Also, what can I count on, if I have B? In out questions require us to move forward and backwards on these chains. It can get confusing. I would think, if B, I can't count on anything specific, because we could have not C or not D or neither. Or it appears I can count on NOT BOTH C and D.
Thank you.