Description: Membership in a class defined as an intersection. (Contributed by Stefan O'Rear, 29-Mar-2015)
Ref | Expression | ||
---|---|---|---|
Hypothesis | elin2.x | |- X = ( B i^i C ) |
|
Assertion | elin2 | |- ( A e. X <-> ( A e. B /\ A e. C ) ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | elin2.x | |- X = ( B i^i C ) |
|
2 | 1 | eleq2i | |- ( A e. X <-> A e. ( B i^i C ) ) |
3 | elin | |- ( A e. ( B i^i C ) <-> ( A e. B /\ A e. C ) ) |
|
4 | 2 3 | bitri | |- ( A e. X <-> ( A e. B /\ A e. C ) ) |