Description: A function's value belongs to its range. (Contributed by Glauco Siliprandi, 2-Jan-2022)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | fnfvelrnd.1 | |- ( ph -> F Fn A ) |
|
| fnfvelrnd.2 | |- ( ph -> B e. A ) |
||
| Assertion | fnfvelrnd | |- ( ph -> ( F ` B ) e. ran F ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | fnfvelrnd.1 | |- ( ph -> F Fn A ) |
|
| 2 | fnfvelrnd.2 | |- ( ph -> B e. A ) |
|
| 3 | fnfvelrn | |- ( ( F Fn A /\ B e. A ) -> ( F ` B ) e. ran F ) |
|
| 4 | 1 2 3 | syl2anc | |- ( ph -> ( F ` B ) e. ran F ) |