| Step | Hyp | Ref
| Expression |
| 1 | | nfa1 1788 |
. . . 4
⊢ Ⅎx∀x A = C |
| 2 | | nfra1 2665 |
. . . 4
⊢ Ⅎx∀x ∈ A B = D |
| 3 | 1, 2 | nfan 1824 |
. . 3
⊢ Ⅎx(∀x A = C ∧ ∀x ∈ A B = D) |
| 4 | | nfv 1619 |
. . 3
⊢ Ⅎy(∀x A = C ∧ ∀x ∈ A B = D) |
| 5 | | rsp 2675 |
. . . . . . 7
⊢ (∀x ∈ A B = D →
(x ∈
A → B = D)) |
| 6 | 5 | imp 418 |
. . . . . 6
⊢ ((∀x ∈ A B = D ∧ x ∈ A) →
B = D) |
| 7 | 6 | eqeq2d 2364 |
. . . . 5
⊢ ((∀x ∈ A B = D ∧ x ∈ A) →
(y = B
↔ y = D)) |
| 8 | 7 | pm5.32da 622 |
. . . 4
⊢ (∀x ∈ A B = D →
((x ∈
A ∧
y = B)
↔ (x ∈ A ∧ y = D))) |
| 9 | | sp 1747 |
. . . . . 6
⊢ (∀x A = C →
A = C) |
| 10 | 9 | eleq2d 2420 |
. . . . 5
⊢ (∀x A = C →
(x ∈
A ↔ x ∈ C)) |
| 11 | 10 | anbi1d 685 |
. . . 4
⊢ (∀x A = C →
((x ∈
A ∧
y = D)
↔ (x ∈ C ∧ y = D))) |
| 12 | 8, 11 | sylan9bbr 681 |
. . 3
⊢ ((∀x A = C ∧ ∀x ∈ A B = D) → ((x
∈ A ∧ y = B) ↔ (x
∈ C ∧ y = D))) |
| 13 | 3, 4, 12 | opabbid 4625 |
. 2
⊢ ((∀x A = C ∧ ∀x ∈ A B = D) → {〈x, y〉 ∣ (x ∈ A ∧ y = B)} = {〈x, y〉 ∣ (x ∈ C ∧ y = D)}) |
| 14 | | df-mpt 5653 |
. 2
⊢ (x ∈ A ↦ B) = {〈x, y〉 ∣ (x ∈ A ∧ y = B)} |
| 15 | | df-mpt 5653 |
. 2
⊢ (x ∈ C ↦ D) = {〈x, y〉 ∣ (x ∈ C ∧ y = D)} |
| 16 | 13, 14, 15 | 3eqtr4g 2410 |
1
⊢ ((∀x A = C ∧ ∀x ∈ A B = D) → (x
∈ A ↦ B) =
(x ∈
C ↦
D)) |