Description: Membership in a range. (Contributed by Scott Fenton, 2-Feb-2011)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | elrn2g | |- ( A e. V -> ( A e. ran B <-> E. x <. x , A >. e. B ) ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | opeq2 | |- ( y = A -> <. x , y >. = <. x , A >. ) | |
| 2 | 1 | eleq1d | |- ( y = A -> ( <. x , y >. e. B <-> <. x , A >. e. B ) ) | 
| 3 | 2 | exbidv | |- ( y = A -> ( E. x <. x , y >. e. B <-> E. x <. x , A >. e. B ) ) | 
| 4 | dfrn3 |  |-  ran B = { y | E. x <. x , y >. e. B } | |
| 5 | 3 4 | elab2g | |- ( A e. V -> ( A e. ran B <-> E. x <. x , A >. e. B ) ) |