Metamath Proof Explorer
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 |
⊢ ( 𝜑 → 𝐹 : 𝐴 ⟶ 𝐵 ) |
|
|
fexd.2 |
⊢ ( 𝜑 → 𝐴 ∈ 𝐶 ) |
|
Assertion |
fexd |
⊢ ( 𝜑 → 𝐹 ∈ V ) |
Proof
Step |
Hyp |
Ref |
Expression |
1 |
|
fexd.1 |
⊢ ( 𝜑 → 𝐹 : 𝐴 ⟶ 𝐵 ) |
2 |
|
fexd.2 |
⊢ ( 𝜑 → 𝐴 ∈ 𝐶 ) |
3 |
|
fex |
⊢ ( ( 𝐹 : 𝐴 ⟶ 𝐵 ∧ 𝐴 ∈ 𝐶 ) → 𝐹 ∈ V ) |
4 |
1 2 3
|
syl2anc |
⊢ ( 𝜑 → 𝐹 ∈ V ) |