Proof of Theorem opabsb
| Step | Hyp | Ref
| Expression |
| 1 | | a9e 809 |
. 2
⊢ ∃y y = w |
| 2 | | ax-17 925 |
. . . . 5
⊢ (v
∈ 〈z, w〉 → ∀y v ∈
〈z, w〉) |
| 3 | | hbopab2 2113 |
. . . . 5
⊢ (v
∈ {〈x, y〉∣φ} → ∀y v ∈
{〈x, y〉∣φ}) |
| 4 | 2, 3 | hbel 1172 |
. . . 4
⊢ (〈z, w〉
∈ {〈x, y〉∣φ} → ∀y〈z,
w〉 ∈ {〈x, y〉∣φ}) |
| 5 | | hbs1 986 |
. . . 4
⊢ ([w /
y][z /
x]φ
→ ∀y[w / y][z / x]φ) |
| 6 | 4, 5 | hbbi 705 |
. . 3
⊢ ((〈z, w〉
∈ {〈x, y〉∣φ} ↔ [w / y][z / x]φ) → ∀y(〈z,
w〉 ∈ {〈x, y〉∣φ} ↔ [w / y][z / x]φ)) |
| 7 | | a9e 809 |
. . . 4
⊢ ∃x x = z |
| 8 | | ax-17 925 |
. . . . . 6
⊢ (y =
w → ∀x y = w) |
| 9 | | ax-17 925 |
. . . . . . . 8
⊢ (v
∈ 〈z, w〉 → ∀x v ∈
〈z, w〉) |
| 10 | | hbopab1 2112 |
. . . . . . . 8
⊢ (v
∈ {〈x, y〉∣φ} → ∀x v ∈
{〈x, y〉∣φ}) |
| 11 | 9, 10 | hbel 1172 |
. . . . . . 7
⊢ (〈z, w〉
∈ {〈x, y〉∣φ} → ∀x〈z,
w〉 ∈ {〈x, y〉∣φ}) |
| 12 | | hbs1 986 |
. . . . . . . 8
⊢ ([z /
x]φ
→ ∀x[z / x]φ) |
| 13 | 12 | hbsb 987 |
. . . . . . 7
⊢ ([w /
y][z /
x]φ
→ ∀x[w / y][z / x]φ) |
| 14 | 11, 13 | hbbi 705 |
. . . . . 6
⊢ ((〈z, w〉
∈ {〈x, y〉∣φ} ↔ [w / y][z / x]φ) → ∀x(〈z,
w〉 ∈ {〈x, y〉∣φ} ↔ [w / y][z / x]φ)) |
| 15 | 8, 14 | hbim 702 |
. . . . 5
⊢ ((y =
w → (〈z, w〉
∈ {〈x, y〉∣φ} ↔ [w / y][z / x]φ)) → ∀x(y = w → (〈z, w〉
∈ {〈x, y〉∣φ} ↔ [w / y][z / x]φ))) |
| 16 | | opeq12 1878 |
. . . . . . . . 9
⊢ ((x =
z ∧ y = w) →
〈x, y〉 = 〈z, w〉) |
| 17 | 16 | eleq1d 1155 |
. . . . . . . 8
⊢ ((x =
z ∧ y = w) →
(〈x, y〉 ∈ {〈x, y〉∣φ} ↔ 〈z, w〉
∈ {〈x, y〉∣φ})) |
| 18 | | opabid 2099 |
. . . . . . . 8
⊢ (〈x, y〉
∈ {〈x, y〉∣φ} ↔ φ) |
| 19 | 17, 18 | syl5bbr 412 |
. . . . . . 7
⊢ ((x =
z ∧ y = w) →
(φ ↔ 〈z, w〉
∈ {〈x, y〉∣φ})) |
| 20 | | sbequ12 865 |
. . . . . . . 8
⊢ (x =
z → (φ ↔ [z / x]φ)) |
| 21 | | sbequ12 865 |
. . . . . . . 8
⊢ (y =
w → ([z / x]φ ↔ [w / y][z / x]φ)) |
| 22 | 20, 21 | sylan9bb 418 |
. . . . . . 7
⊢ ((x =
z ∧ y = w) →
(φ ↔ [w / y][z / x]φ)) |
| 23 | 19, 22 | bitr3d 408 |
. . . . . 6
⊢ ((x =
z ∧ y = w) →
(〈z, w〉 ∈ {〈x, y〉∣φ} ↔ [w / y][z / x]φ)) |
| 24 | 23 | exp 291 |
. . . . 5
⊢ (x =
z → (y = w →
(〈z, w〉 ∈ {〈x, y〉∣φ} ↔ [w / y][z / x]φ))) |
| 25 | 15, 24 | 19.23ai 746 |
. . . 4
⊢ (∃x x = z → (y =
w → (〈z, w〉
∈ {〈x, y〉∣φ} ↔ [w / y][z / x]φ))) |
| 26 | 7, 25 | ax-mp 6 |
. . 3
⊢ (y =
w → (〈z, w〉
∈ {〈x, y〉∣φ} ↔ [w / y][z / x]φ)) |
| 27 | 6, 26 | 19.23ai 746 |
. 2
⊢ (∃y y = w → (〈z, w〉
∈ {〈x, y〉∣φ} ↔ [w / y][z / x]φ)) |
| 28 | 1, 27 | ax-mp 6 |
1
⊢ (〈z, w〉
∈ {〈x, y〉∣φ} ↔ [w / y][z / x]φ) |