Description: An indexed set is dominated by the indexing set. (Contributed by Jeff Madsen, 2-Sep-2009)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | abrexdom2 | |- ( A e. V -> { x | E. y e. A x = B } ~<_ A ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | moeq | |- E* x x = B | |
| 2 | 1 | a1i | |- ( y e. A -> E* x x = B ) | 
| 3 | 2 | abrexdom |  |-  ( A e. V -> { x | E. y e. A x = B } ~<_ A ) |