Description: Two ways of saying a set is an element of the converse of the intersection of a class. (Contributed by RP, 19-Aug-2020)
Ref | Expression | ||
---|---|---|---|
Assertion | elcnvintab | |- ( A e. `' |^| { x | ph } <-> ( A e. ( _V X. _V ) /\ A. x ( ph -> A e. `' x ) ) ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | eqid | |- ( y e. ( _V X. _V ) |-> <. ( 2nd ` y ) , ( 1st ` y ) >. ) = ( y e. ( _V X. _V ) |-> <. ( 2nd ` y ) , ( 1st ` y ) >. ) |
|
2 | 1 | elcnvlem | |- ( A e. `' |^| { x | ph } <-> ( A e. ( _V X. _V ) /\ ( ( y e. ( _V X. _V ) |-> <. ( 2nd ` y ) , ( 1st ` y ) >. ) ` A ) e. |^| { x | ph } ) ) |
3 | 1 | elcnvlem | |- ( A e. `' x <-> ( A e. ( _V X. _V ) /\ ( ( y e. ( _V X. _V ) |-> <. ( 2nd ` y ) , ( 1st ` y ) >. ) ` A ) e. x ) ) |
4 | 2 3 | elmapintab | |- ( A e. `' |^| { x | ph } <-> ( A e. ( _V X. _V ) /\ A. x ( ph -> A e. `' x ) ) ) |