Description: Two ways of saying that two classes are disjoint. (Contributed by NM, 17-May-1998)
Ref | Expression | ||
---|---|---|---|
Assertion | disj2 | |- ( ( A i^i B ) = (/) <-> A C_ ( _V \ B ) ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | ssv | |- A C_ _V |
|
2 | reldisj | |- ( A C_ _V -> ( ( A i^i B ) = (/) <-> A C_ ( _V \ B ) ) ) |
|
3 | 1 2 | ax-mp | |- ( ( A i^i B ) = (/) <-> A C_ ( _V \ B ) ) |