Description: The functional image of a function value exists. (Contributed by RP, 31-Oct-2024)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | fnimafnex.f | |- F Fn B |
|
| Assertion | fnimafnex | |- ( F " ( G ` A ) ) e. _V |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | fnimafnex.f | |- F Fn B |
|
| 2 | fnfun | |- ( F Fn B -> Fun F ) |
|
| 3 | 1 2 | ax-mp | |- Fun F |
| 4 | fvex | |- ( G ` A ) e. _V |
|
| 5 | funimaexg | |- ( ( Fun F /\ ( G ` A ) e. _V ) -> ( F " ( G ` A ) ) e. _V ) |
|
| 6 | 3 4 5 | mp2an | |- ( F " ( G ` A ) ) e. _V |