Description: The converse of a binary relation over a range Cartesian product. (Contributed by Peter Mazsa, 11-Jul-2021)
Ref | Expression | ||
---|---|---|---|
Assertion | br1cnvxrn2 | |- ( B e. V -> ( A `' ( R |X. S ) B <-> E. y E. z ( A = <. y , z >. /\ B R y /\ B S z ) ) ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | xrnrel | |- Rel ( R |X. S ) |
|
2 | 1 | relbrcnv | |- ( A `' ( R |X. S ) B <-> B ( R |X. S ) A ) |
3 | brxrn2 | |- ( B e. V -> ( B ( R |X. S ) A <-> E. y E. z ( A = <. y , z >. /\ B R y /\ B S z ) ) ) |
|
4 | 2 3 | syl5bb | |- ( B e. V -> ( A `' ( R |X. S ) B <-> E. y E. z ( A = <. y , z >. /\ B R y /\ B S z ) ) ) |