1. P ⊃ ~M
2. C ⊃ M
3. ~L v C
4. (~P ⊃ ~E) • (~E ⊃ ~C)
5. P v ~P /~L
6. ~P ⊃ ~E 4, simplification
7. ~~E ⊃ ~~P 6, transposition
8. E ⊃ P 7, double negation
9. E ⊃ ~M 8,1 hypothetical syllogism
10. ~E v ~M 9, material implication
11. ~(E • M) 10, deMorgan's law
12. ~C v M 2, material implication
13. (~E ⊃ ~C) • (~P ⊃ ~E) 4, commutation
14. ~E ⊃ ~C 13, simplification
15. ~~E v ~C 14, material implication
16. E v ~C 15, double negation
17. ~C v E 16, commutation
18. (~C v E) • (~C v M) 17,12, conjunction
19. ~C v (E • M) 18, distribution
20. (E • M) v ~C 19, commutation
21. ~C 20,11, disjunctive syllogism
22. C v ~L 3, commutation
23. ~L 22,21 disjunctive syllogism
Edwin