1. ~B&R
2. R⊃~(MvP)
3. (N⊃S)⊃~I
4. N⊃L
5. E⊃(S≡L)
6. E /.: ~I&~M
7. R&~B 1, Commutation
8. R 7, Simplification
9. ~(MvP) 2,8, Modus Ponens
10. ~M&~P 9, DeMorgan's Law
11. ~M 10, Simplification
12. S≡L 5,6, Modus Ponens
13. (S⊃L)&(L⊃S) 12, Material equivalence
14. L⊃S 13, Simplification
15. N⊃S 4,14, Hypothetical syllogism
16. ~I 3,15, Modus Ponens
17. ~I&~M 16,11, Conjunction
Edwin