Description: If the domain of a mapping is a set, the function is a set. (Contributed by Glauco Siliprandi, 26-Jun-2021)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | fexd.1 | |- ( ph -> F : A --> B ) |
|
| fexd.2 | |- ( ph -> A e. C ) |
||
| Assertion | fexd | |- ( ph -> F e. _V ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | fexd.1 | |- ( ph -> F : A --> B ) |
|
| 2 | fexd.2 | |- ( ph -> A e. C ) |
|
| 3 | fex | |- ( ( F : A --> B /\ A e. C ) -> F e. _V ) |
|
| 4 | 1 2 3 | syl2anc | |- ( ph -> F e. _V ) |