Description: Value of the converse of the operator, ( A O B ) , which maps between relations and functions for relations between base sets, A and B . (Contributed by RP, 27-Apr-2021)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | rfovd.rf | |- O = ( a e. _V , b e. _V |-> ( r e. ~P ( a X. b ) |-> ( x e. a |-> { y e. b | x r y } ) ) ) | |
| rfovd.a | |- ( ph -> A e. V ) | ||
| rfovd.b | |- ( ph -> B e. W ) | ||
| rfovcnvf1od.f | |- F = ( A O B ) | ||
| Assertion | rfovcnvd | |- ( ph -> `' F = ( f e. ( ~P B ^m A ) |-> { <. x , y >. | ( x e. A /\ y e. ( f ` x ) ) } ) ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | rfovd.rf |  |-  O = ( a e. _V , b e. _V |-> ( r e. ~P ( a X. b ) |-> ( x e. a |-> { y e. b | x r y } ) ) ) | |
| 2 | rfovd.a | |- ( ph -> A e. V ) | |
| 3 | rfovd.b | |- ( ph -> B e. W ) | |
| 4 | rfovcnvf1od.f | |- F = ( A O B ) | |
| 5 | 1 2 3 4 | rfovcnvf1od |  |-  ( ph -> ( F : ~P ( A X. B ) -1-1-onto-> ( ~P B ^m A ) /\ `' F = ( f e. ( ~P B ^m A ) |-> { <. x , y >. | ( x e. A /\ y e. ( f ` x ) ) } ) ) ) | 
| 6 | 5 | simprd |  |-  ( ph -> `' F = ( f e. ( ~P B ^m A ) |-> { <. x , y >. | ( x e. A /\ y e. ( f ` x ) ) } ) ) |