Comments on Prove that $A \leftrightarrow \lnot\lnot A$ (WIP)
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Prove that $A \leftrightarrow \lnot\lnot A$ (WIP)
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Task
Prove that $A \leftrightarrow \lnot\lnot A$ using only the following axioms:
- $P \rightarrow (Q \rightarrow P)$
- $(P \rightarrow (Q \rightarrow R)) \rightarrow ((P \rightarrow Q) \rightarrow (P \rightarrow R))$
- $(P \rightarrow Q) \leftrightarrow (\lnot Q \rightarrow \lnot P)$
Scoring
Your score will be the number of times you apply any of the axioms above.
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