Description: Alternate definition of range. Definition 4 of Suppes p. 60. (Contributed by NM, 27-Dec-1996)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | dfrn2 | |- ran A = { y | E. x x A y } | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | df-rn | |- ran A = dom `' A | |
| 2 | df-dm |  |-  dom `' A = { y | E. x y `' A x } | |
| 3 | vex | |- y e. _V | |
| 4 | vex | |- x e. _V | |
| 5 | 3 4 | brcnv | |- ( y `' A x <-> x A y ) | 
| 6 | 5 | exbii | |- ( E. x y `' A x <-> E. x x A y ) | 
| 7 | 6 | abbii |  |-  { y | E. x y `' A x } = { y | E. x x A y } | 
| 8 | 1 2 7 | 3eqtri |  |-  ran A = { y | E. x x A y } |