Number | Statement | Lines Used | Reason | |
---|---|---|---|---|
:. | (P -> Q) <--> (P -> (Q v ~P)) | |||
1 | P -> Q | ACP | ||
2 | ~P v Q | 1 | MI | |
3 | (~P v Q) v ~P | 2 | Add | |
4 | ~P v (Q v ~P) | 3 | Assoc | |
5 | P -> (Q v ~P) | 4 | MI | |
6 | [P -> Q] -> [P -> (Q v ~P)] | 1-5 | CP | |
7 | P -> (Q v ~P) | ACP | ||
8 | ~P v (Q v ~P) | 7 | MI | |
9 | ~P v (~P v Q) | 8 | Comm | |
10 | (~P v ~P) v Q | 9 | Assoc | |
11 | ~P v Q | 10 | Taut | |
12 | P -> Q | 11 | MI | |
13 | [P -> (Q v ~P)] -> [P -> Q] | 7-12 | CP | |
14 | {[P -> Q] -> [P -> (Q v ~P)]} & {[P -> (Q v ~P)] -> [P -> Q]} | 6,13 | Conj | |
15 | (P -> Q) <--> (P -> (Q v ~P)) | 14 | ME |