Proof of Theorem opelxp
| Step | Hyp | Ref
| Expression |
| 1 | | opelxpex 2445 |
. 2
⊢ (〈A, B〉
∈ (C × D) → A
∈ V) |
| 2 | | elisset 1354 |
. . 3
⊢ (A
∈ C → A ∈ V) |
| 3 | 2 | adantr 306 |
. 2
⊢ ((A
∈ C ∧ B ∈ D)
→ A ∈ V) |
| 4 | | opeq1 1876 |
. . . 4
⊢ (z =
A → 〈z, B〉 =
〈A, B〉) |
| 5 | 4 | eleq1d 1155 |
. . 3
⊢ (z =
A → (〈z, B〉
∈ (C × D) ↔ 〈A, B〉
∈ (C × D))) |
| 6 | | eleq1 1149 |
. . . 4
⊢ (z =
A → (z ∈ C
↔ A ∈ C)) |
| 7 | 6 | anbi1d 469 |
. . 3
⊢ (z =
A → ((z ∈ C ∧
B ∈ D) ↔ (A
∈ C ∧ B ∈ D))) |
| 8 | | cleqcom 1103 |
. . . . . . . . . . 11
⊢ (〈z, B〉 =
〈x, y〉 ↔ 〈x, y〉 =
〈z, B〉) |
| 9 | | visset 1350 |
. . . . . . . . . . . 12
⊢ x
∈ V |
| 10 | | visset 1350 |
. . . . . . . . . . . 12
⊢ y
∈ V |
| 11 | | opelxp.1 |
. . . . . . . . . . . 12
⊢ B
∈ V |
| 12 | 9, 10, 11 | opth 1898 |
. . . . . . . . . . 11
⊢ (〈x, y〉 =
〈z, B〉 ↔ (x = z ∧
y = B)) |
| 13 | 8, 12 | bitr 151 |
. . . . . . . . . 10
⊢ (〈z, B〉 =
〈x, y〉 ↔ (x = z ∧
y = B)) |
| 14 | 13 | anbi1i 368 |
. . . . . . . . 9
⊢ ((〈z, B〉 =
〈x, y〉 ∧ (x
∈ C ∧ y ∈ D))
↔ ((x = z ∧ y =
B) ∧ (x ∈ C ∧
y ∈ D))) |
| 15 | | an4 388 |
. . . . . . . . 9
⊢ (((x =
z ∧ y = B) ∧
(x ∈ C ∧ y ∈
D)) ↔ ((x = z ∧
x ∈ C) ∧ (y =
B ∧ y ∈ D))) |
| 16 | 14, 15 | bitr 151 |
. . . . . . . 8
⊢ ((〈z, B〉 =
〈x, y〉 ∧ (x
∈ C ∧ y ∈ D))
↔ ((x = z ∧ x ∈
C) ∧ (y = B ∧
y ∈ D))) |
| 17 | 16 | biex 733 |
. . . . . . 7
⊢ (∃y(〈z,
B〉 = 〈x, y〉 ∧
(x ∈ C ∧ y ∈
D)) ↔ ∃y((x = z ∧ x ∈
C) ∧ (y = B ∧
y ∈ D))) |
| 18 | | 19.42v 966 |
. . . . . . 7
⊢ (∃y((x = z ∧ x ∈
C) ∧ (y = B ∧
y ∈ D)) ↔ ((x =
z ∧ x ∈ C)
∧ ∃y(y = B ∧
y ∈ D))) |
| 19 | 17, 18 | bitr 151 |
. . . . . 6
⊢ (∃y(〈z,
B〉 = 〈x, y〉 ∧
(x ∈ C ∧ y ∈
D)) ↔ ((x = z ∧
x ∈ C) ∧ ∃y(y = B ∧ y ∈
D))) |
| 20 | 19 | biex 733 |
. . . . 5
⊢ (∃x∃y(〈z,
B〉 = 〈x, y〉 ∧
(x ∈ C ∧ y ∈
D)) ↔ ∃x((x = z ∧ x ∈
C) ∧ ∃y(y = B ∧ y ∈
D))) |
| 21 | | 19.41v 963 |
. . . . 5
⊢ (∃x((x = z ∧ x ∈
C) ∧ ∃y(y = B ∧ y ∈
D)) ↔ (∃x(x = z ∧ x ∈
C) ∧ ∃y(y = B ∧ y ∈
D))) |
| 22 | 20, 21 | bitr 151 |
. . . 4
⊢ (∃x∃y(〈z,
B〉 = 〈x, y〉 ∧
(x ∈ C ∧ y ∈
D)) ↔ (∃x(x = z ∧ x ∈
C) ∧ ∃y(y = B ∧ y ∈
D))) |
| 23 | | elxp 2442 |
. . . 4
⊢ (〈z, B〉
∈ (C × D) ↔ ∃x∃y(〈z,
B〉 = 〈x, y〉 ∧
(x ∈ C ∧ y ∈
D))) |
| 24 | | df-clel 1099 |
. . . . 5
⊢ (z
∈ C ↔ ∃x(x = z ∧ x ∈
C)) |
| 25 | | df-clel 1099 |
. . . . 5
⊢ (B
∈ D ↔ ∃y(y = B ∧ y ∈
D)) |
| 26 | 24, 25 | anbi12i 369 |
. . . 4
⊢ ((z
∈ C ∧ B ∈ D)
↔ (∃x(x = z ∧
x ∈ C) ∧ ∃y(y = B ∧ y ∈
D))) |
| 27 | 22, 23, 26 | 3bitr4 158 |
. . 3
⊢ (〈z, B〉
∈ (C × D) ↔ (z
∈ C ∧ B ∈ D)) |
| 28 | 5, 7, 27 | vtoclbg 1384 |
. 2
⊢ (A
∈ V → (〈A, B〉 ∈ (C × D)
↔ (A ∈ C ∧ B ∈
D))) |
| 29 | 1, 3, 28 | pm5.21nii 504 |
1
⊢ (〈A, B〉
∈ (C × D) ↔ (A
∈ C ∧ B ∈ D)) |