Proof of Theorem rabxfr
| Step | Hyp | Ref
| Expression |
| 1 | | rabxfr.3 |
. . . . . . . 8
⊢ (y ∈ D → A ∈ D) |
| 2 | | ibibr 602 |
. . . . . . . 8
⊢ ((y ∈ D → A ∈ D) ↔
(y ∈
D → (A ∈ D ↔ y ∈ D))) |
| 3 | 1, 2 | mpbi 196 |
. . . . . . 7
⊢ (y ∈ D → (A
∈ D
↔ y ∈ D)) |
| 4 | 3 | anbi1d 628 |
. . . . . 6
⊢ (y ∈ D → ((A
∈ D ⋀ ψ)
↔ (y ∈ D ⋀ ψ))) |
| 5 | | rabxfr.4 |
. . . . . . 7
⊢ (x = A →
(φ ↔ ψ)) |
| 6 | 5 | elrab 1952 |
. . . . . 6
⊢ (A ∈ {x ∈ D∣φ} ↔ (A ∈ D ⋀ ψ)) |
| 7 | | rabid 1816 |
. . . . . 6
⊢ (y ∈ {y ∈ D∣ψ} ↔ (y ∈ D ⋀ ψ)) |
| 8 | 4, 6, 7 | 3bitr4g 566 |
. . . . 5
⊢ (y ∈ D → (A
∈ {x
∈ D∣φ} ↔
y ∈
{y ∈
D∣ψ})) |
| 9 | 8 | rabbii 1852 |
. . . 4
⊢ {y ∈ D∣A ∈ {x ∈ D∣φ}} = {y
∈ D∣y ∈ {y ∈ D∣ψ}} |
| 10 | 9 | eleq2i 1585 |
. . 3
⊢ (B ∈ {y ∈ D∣A ∈ {x ∈ D∣φ}} ↔ B ∈ {y ∈ D∣y ∈ {y ∈ D∣ψ}}) |
| 11 | | rabxfr.1 |
. . . 4
⊢ (z ∈ B → ∀y z ∈ B) |
| 12 | | ax-17 1012 |
. . . 4
⊢ (z ∈ D → ∀y z ∈ D) |
| 13 | | rabxfr.2 |
. . . . 5
⊢ (z ∈ C → ∀y z ∈ C) |
| 14 | | ax-17 1012 |
. . . . 5
⊢ (z ∈ {x ∈ D∣φ} → ∀y z ∈ {x ∈ D∣φ}) |
| 15 | 13, 14 | hbel 1613 |
. . . 4
⊢ (C ∈ {x ∈ D∣φ} → ∀y C ∈ {x ∈ D∣φ}) |
| 16 | | rabxfr.5 |
. . . . 5
⊢ (y = B →
A = C) |
| 17 | 16 | eleq1d 1587 |
. . . 4
⊢ (y = B →
(A ∈
{x ∈
D∣φ} ↔ C ∈ {x ∈ D∣φ})) |
| 18 | 11, 12, 15, 17 | elrabf 1951 |
. . 3
⊢ (B ∈ {y ∈ D∣A ∈ {x ∈ D∣φ}} ↔ (B ∈ D ⋀ C ∈ {x ∈ D∣φ})) |
| 19 | | hbrab1 1819 |
. . . . 5
⊢ (z ∈ {y ∈ D∣ψ} → ∀y z ∈ {y ∈ D∣ψ}) |
| 20 | 11, 19 | hbel 1613 |
. . . 4
⊢ (B ∈ {y ∈ D∣ψ} → ∀y B ∈ {y ∈ D∣ψ}) |
| 21 | | eleq1 1581 |
. . . 4
⊢ (y = B →
(y ∈
{y ∈
D∣ψ} ↔ B ∈ {y ∈ D∣ψ})) |
| 22 | 11, 12, 20, 21 | elrabf 1951 |
. . 3
⊢ (B ∈ {y ∈ D∣y ∈ {y ∈ D∣ψ}} ↔ (B ∈ D ⋀ B ∈ {y ∈ D∣ψ})) |
| 23 | 10, 18, 22 | 3bitr3i 188 |
. 2
⊢ ((B ∈ D ⋀ C ∈ {x ∈ D∣φ}) ↔ (B ∈ D ⋀ B ∈ {y ∈ D∣ψ})) |
| 24 | | pm5.32 655 |
. 2
⊢ ((B ∈ D → (C
∈ {x
∈ D∣φ} ↔
B ∈
{y ∈
D∣ψ})) ↔ ((B ∈ D ⋀ C ∈ {x ∈ D∣φ}) ↔ (B ∈ D ⋀ B ∈ {y ∈ D∣ψ}))) |
| 25 | 23, 24 | mpbir 197 |
1
⊢ (B ∈ D → (C
∈ {x
∈ D∣φ} ↔
B ∈
{y ∈
D∣ψ})) |