Logic / Unit 5 Logic 200 short lesson, about 20 seconds
Constructive Dilemma as a Proof Move
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The idea
From (p ⊃ q) · (r ⊃ s) and p ∨ r, derive q ∨ s.
In practice
The two-conditional package plus the trigger disjunction yields the outcome disjunction.
Where people slip
The conditionals must arrive as a single conjoined line. Two loose conditionals need a Conj step first (198).
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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