Question 1141037
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1. ∼R v P
2. R v ∼P     / R ≡ P

3. R ⊃ P                1, Material implication
4. ~P v R               2, Commutation
5. P ⊃ R                4, Material implication
6. (R ⊃ P) • (P ⊃ R)   3,5, Conjunction
7. R ≡ P                6, Material equivalence

Edwin</pre>