Description: The range of a function expressed as a collection of the function's values, analogous to fnrnfv . (Contributed by Alexander van der Vekens, 25-May-2017)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | fnrnafv | |- ( F Fn A -> ran F = { y | E. x e. A y = ( F ''' x ) } ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | dfafn5a | |- ( F Fn A -> F = ( x e. A |-> ( F ''' x ) ) ) | |
| 2 | 1 | rneqd | |- ( F Fn A -> ran F = ran ( x e. A |-> ( F ''' x ) ) ) | 
| 3 | eqid | |- ( x e. A |-> ( F ''' x ) ) = ( x e. A |-> ( F ''' x ) ) | |
| 4 | 3 | rnmpt |  |-  ran ( x e. A |-> ( F ''' x ) ) = { y | E. x e. A y = ( F ''' x ) } | 
| 5 | 2 4 | eqtrdi |  |-  ( F Fn A -> ran F = { y | E. x e. A y = ( F ''' x ) } ) |