Proof of Theorem inopab
| Step | Hyp | Ref
| Expression |
| 1 | | relopab 2494 |
. . 3
⊢ Rel {〈x, y〉∣φ} |
| 2 | | relin 2491 |
. . 3
⊢ (Rel {〈x, y〉∣φ} → Rel ({〈x, y〉∣φ} ∩ {〈x, y〉∣ψ})) |
| 3 | 1, 2 | ax-mp 6 |
. 2
⊢ Rel ({〈x, y〉∣φ} ∩ {〈x, y〉∣ψ}) |
| 4 | | relopab 2494 |
. 2
⊢ Rel {〈x, y〉∣(φ ∧ ψ)} |
| 5 | | sban 889 |
. . . 4
⊢ ([w /
y]([z /
x]φ
∧ [z / x]ψ) ↔
([w / y][z / x]φ ∧
[w / y][z / x]ψ)) |
| 6 | | sban 889 |
. . . . 5
⊢ ([z /
x](φ ∧ ψ) ↔ ([z / x]φ ∧ [z / x]ψ)) |
| 7 | 6 | bisb 855 |
. . . 4
⊢ ([w /
y][z /
x](φ ∧ ψ) ↔ [w / y]([z / x]φ ∧ [z / x]ψ)) |
| 8 | | opabsb 2114 |
. . . . 5
⊢ (〈z, w〉
∈ {〈x, y〉∣φ} ↔ [w / y][z / x]φ) |
| 9 | | opabsb 2114 |
. . . . 5
⊢ (〈z, w〉
∈ {〈x, y〉∣ψ} ↔ [w / y][z / x]ψ) |
| 10 | 8, 9 | anbi12i 369 |
. . . 4
⊢ ((〈z, w〉
∈ {〈x, y〉∣φ} ∧ 〈z, w〉
∈ {〈x, y〉∣ψ}) ↔ ([w / y][z / x]φ ∧ [w / y][z / x]ψ)) |
| 11 | 5, 7, 10 | 3bitr4r 159 |
. . 3
⊢ ((〈z, w〉
∈ {〈x, y〉∣φ} ∧ 〈z, w〉
∈ {〈x, y〉∣ψ}) ↔ [w / y][z / x](φ ∧ ψ)) |
| 12 | | elin 1635 |
. . 3
⊢ (〈z, w〉
∈ ({〈x, y〉∣φ} ∩ {〈x, y〉∣ψ}) ↔ (〈z, w〉
∈ {〈x, y〉∣φ} ∧ 〈z, w〉
∈ {〈x, y〉∣ψ})) |
| 13 | | opabsb 2114 |
. . 3
⊢ (〈z, w〉
∈ {〈x, y〉∣(φ ∧ ψ)} ↔ [w / y][z / x](φ ∧ ψ)) |
| 14 | 11, 12, 13 | 3bitr4 158 |
. 2
⊢ (〈z, w〉
∈ ({〈x, y〉∣φ} ∩ {〈x, y〉∣ψ}) ↔ 〈z, w〉
∈ {〈x, y〉∣(φ ∧ ψ)}) |
| 15 | 3, 4, 14 | cleqreli 2484 |
1
⊢ ({〈x, y〉∣φ} ∩ {〈x, y〉∣ψ}) = {〈x, y〉∣(φ ∧ ψ)} |