Description: Membership in class intersection. (Contributed by Glauco Siliprandi, 3-Jan-2021)
Ref | Expression | ||
---|---|---|---|
Hypotheses | elintdv.1 | |- ( ph -> A e. V ) |
|
elintdv.2 | |- ( ( ph /\ x e. B ) -> A e. x ) |
||
Assertion | elintdv | |- ( ph -> A e. |^| B ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | elintdv.1 | |- ( ph -> A e. V ) |
|
2 | elintdv.2 | |- ( ( ph /\ x e. B ) -> A e. x ) |
|
3 | nfv | |- F/ x ph |
|
4 | 3 1 2 | elintd | |- ( ph -> A e. |^| B ) |