Description: Two ways to express a binary relation which is the intersection of a class. (Contributed by RP, 4-Apr-2020)
Ref | Expression | ||
---|---|---|---|
Assertion | brintclab | |- ( A |^| { x | ph } B <-> A. x ( ph -> <. A , B >. e. x ) ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | df-br | |- ( A |^| { x | ph } B <-> <. A , B >. e. |^| { x | ph } ) |
|
2 | opex | |- <. A , B >. e. _V |
|
3 | 2 | elintab | |- ( <. A , B >. e. |^| { x | ph } <-> A. x ( ph -> <. A , B >. e. x ) ) |
4 | 1 3 | bitri | |- ( A |^| { x | ph } B <-> A. x ( ph -> <. A , B >. e. x ) ) |