Metamath Proof Explorer
Description: Functionality of a class given by a maps-to notation. (Contributed by FL, 17-Feb-2008) (Revised by Mario Carneiro, 31-May-2014)
|
|
Ref |
Expression |
|
Hypothesis |
funmpt2.1 |
⊢ 𝐹 = ( 𝑥 ∈ 𝐴 ↦ 𝐵 ) |
|
Assertion |
funmpt2 |
⊢ Fun 𝐹 |
Proof
Step |
Hyp |
Ref |
Expression |
1 |
|
funmpt2.1 |
⊢ 𝐹 = ( 𝑥 ∈ 𝐴 ↦ 𝐵 ) |
2 |
|
funmpt |
⊢ Fun ( 𝑥 ∈ 𝐴 ↦ 𝐵 ) |
3 |
1
|
funeqi |
⊢ ( Fun 𝐹 ↔ Fun ( 𝑥 ∈ 𝐴 ↦ 𝐵 ) ) |
4 |
2 3
|
mpbir |
⊢ Fun 𝐹 |