Description: Restricted subset binary relation. (Contributed by Peter Mazsa, 25-Nov-2019)
Ref | Expression | ||
---|---|---|---|
Assertion | brssrres | |- ( C e. V -> ( B ( _S |` A ) C <-> ( B e. A /\ B C_ C ) ) ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | brres | |- ( C e. V -> ( B ( _S |` A ) C <-> ( B e. A /\ B _S C ) ) ) |
|
2 | brssr | |- ( C e. V -> ( B _S C <-> B C_ C ) ) |
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3 | 2 | anbi2d | |- ( C e. V -> ( ( B e. A /\ B _S C ) <-> ( B e. A /\ B C_ C ) ) ) |
4 | 1 3 | bitrd | |- ( C e. V -> ( B ( _S |` A ) C <-> ( B e. A /\ B C_ C ) ) ) |