Description: Given a is equivalent to b, there exists a proof for (not (a xor b)). (Contributed by Jarvin Udandy, 28-Aug-2016)
Ref | Expression | ||
---|---|---|---|
Hypothesis | aisbnaxb.1 | ||
Assertion | aisbnaxb |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | aisbnaxb.1 | ||
2 | 1 | notnoti | |
3 | df-xor | ||
4 | 2 3 | mtbir |