Logic / Unit 5 Logic 204 short lesson, about 20 seconds
De Morgan's Rules
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The idea
~(p · q) :: ~p ∨ ~q, and ~(p ∨ q) :: ~p · ~q.
In practice
"Not both passed" means at least one failed. "Neither passed" means both failed.
Where people slip
The negation distributes and flips the connective. Forgetting the flip is the unit's most common error — and video 118's warning, formalized.
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