Description: Given a is equivalent to (not b), c is equivalent to a. there exists a proof for ( c xor b ). (Contributed by Jarvin Udandy, 7-Sep-2016)
Ref | Expression | ||
---|---|---|---|
Hypotheses | axorbciffatcxorb.1 | |- ( ph \/_ ps ) |
|
axorbciffatcxorb.2 | |- ( ch <-> ph ) |
||
Assertion | axorbciffatcxorb | |- ( ch \/_ ps ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | axorbciffatcxorb.1 | |- ( ph \/_ ps ) |
|
2 | axorbciffatcxorb.2 | |- ( ch <-> ph ) |
|
3 | 1 | axorbtnotaiffb | |- -. ( ph <-> ps ) |
4 | xor3 | |- ( -. ( ph <-> ps ) <-> ( ph <-> -. ps ) ) |
|
5 | 3 4 | mpbi | |- ( ph <-> -. ps ) |
6 | 5 2 | aiffnbandciffatnotciffb | |- -. ( ch <-> ps ) |
7 | df-xor | |- ( ( ch \/_ ps ) <-> -. ( ch <-> ps ) ) |
|
8 | 6 7 | mpbir | |- ( ch \/_ ps ) |