Logic / Unit 5 Logic 220 short lesson, about 20 seconds
The Common Proof Errors
Captions available
The idea
The recurring five: Simp on a non-conjunction; inference rules applied to parts of lines; citing discharged lines; DS by affirming; negation mismatches unfixed by DN.
In practice
Each shown in a single wrong line with the error circled.
Where people slip
Every one of these is a valid rule applied where its conditions don't hold. The rules are never wrong; the reach is.
Your place on the trail
Every lesson rests on earlier ones and opens later ones. Tap any to jump.
Builds on
Unlocks
- Nothing yet depends on this.
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