Proof of Theorem opelopabg
| Step | Hyp | Ref
| Expression |
| 1 | | elex 1356 |
. . . 4
⊢ (A
∈ C → ∃x x = A) |
| 2 | | elex 1356 |
. . . 4
⊢ (B
∈ D → ∃y y = B) |
| 3 | 1, 2 | anim12i 268 |
. . 3
⊢ ((A
∈ C ∧ B ∈ D)
→ (∃x x = A ∧
∃y y = B)) |
| 4 | | eeanv 980 |
. . 3
⊢ (∃x∃y(x = A ∧ y =
B) ↔ (∃x x = A ∧ ∃y
y = B)) |
| 5 | 3, 4 | sylibr 175 |
. 2
⊢ ((A
∈ C ∧ B ∈ D)
→ ∃x∃y(x = A ∧ y =
B)) |
| 6 | | ax-17 925 |
. . . . 5
⊢ (z
∈ 〈A, B〉 → ∀x z ∈
〈A, B〉) |
| 7 | | hbopab1 2112 |
. . . . 5
⊢ (z
∈ {〈x, y〉∣φ} → ∀x z ∈
{〈x, y〉∣φ}) |
| 8 | 6, 7 | hbel 1172 |
. . . 4
⊢ (〈A, B〉
∈ {〈x, y〉∣φ} → ∀x〈A,
B〉 ∈ {〈x, y〉∣φ}) |
| 9 | | ax-17 925 |
. . . 4
⊢ (χ
→ ∀xχ) |
| 10 | 8, 9 | hbbi 705 |
. . 3
⊢ ((〈A, B〉
∈ {〈x, y〉∣φ} ↔ χ) → ∀x(〈A,
B〉 ∈ {〈x, y〉∣φ} ↔ χ)) |
| 11 | | ax-17 925 |
. . . . . 6
⊢ (z
∈ 〈A, B〉 → ∀y z ∈
〈A, B〉) |
| 12 | | hbopab2 2113 |
. . . . . 6
⊢ (z
∈ {〈x, y〉∣φ} → ∀y z ∈
{〈x, y〉∣φ}) |
| 13 | 11, 12 | hbel 1172 |
. . . . 5
⊢ (〈A, B〉
∈ {〈x, y〉∣φ} → ∀y〈A,
B〉 ∈ {〈x, y〉∣φ}) |
| 14 | | ax-17 925 |
. . . . 5
⊢ (χ
→ ∀yχ) |
| 15 | 13, 14 | hbbi 705 |
. . . 4
⊢ ((〈A, B〉
∈ {〈x, y〉∣φ} ↔ χ) → ∀y(〈A,
B〉 ∈ {〈x, y〉∣φ} ↔ χ)) |
| 16 | | opeq12 1878 |
. . . . . . 7
⊢ ((x =
A ∧ y = B) →
〈x, y〉 = 〈A, B〉) |
| 17 | 16 | eleq1d 1155 |
. . . . . 6
⊢ ((x =
A ∧ y = B) →
(〈x, y〉 ∈ {〈x, y〉∣φ} ↔ 〈A, B〉
∈ {〈x, y〉∣φ})) |
| 18 | | opabid 2099 |
. . . . . 6
⊢ (〈x, y〉
∈ {〈x, y〉∣φ} ↔ φ) |
| 19 | 17, 18 | syl5bbr 412 |
. . . . 5
⊢ ((x =
A ∧ y = B) →
(φ ↔ 〈A, B〉
∈ {〈x, y〉∣φ})) |
| 20 | | opelopabg.1 |
. . . . . 6
⊢ (x =
A → (φ ↔ ψ)) |
| 21 | | opelopabg.2 |
. . . . . 6
⊢ (y =
B → (ψ ↔ χ)) |
| 22 | 20, 21 | sylan9bb 418 |
. . . . 5
⊢ ((x =
A ∧ y = B) →
(φ ↔ χ)) |
| 23 | 19, 22 | bitr3d 408 |
. . . 4
⊢ ((x =
A ∧ y = B) →
(〈A, B〉 ∈ {〈x, y〉∣φ} ↔ χ)) |
| 24 | 15, 23 | 19.23ai 746 |
. . 3
⊢ (∃y(x = A ∧ y =
B) → (〈A, B〉
∈ {〈x, y〉∣φ} ↔ χ)) |
| 25 | 10, 24 | 19.23ai 746 |
. 2
⊢ (∃x∃y(x = A ∧ y =
B) → (〈A, B〉
∈ {〈x, y〉∣φ} ↔ χ)) |
| 26 | 5, 25 | syl 12 |
1
⊢ ((A
∈ C ∧ B ∈ D)
→ (〈A, B〉 ∈ {〈x, y〉∣φ} ↔ χ)) |