Proof of Theorem dvelimh
Step | Hyp | Ref
| Expression |
1 | | hba1 1786 |
. . . . 5
⊢ (∀z(z = y →
φ) → ∀z∀z(z = y →
φ)) |
2 | | ax10o 1952 |
. . . . . 6
⊢ (∀z z = x →
(∀z∀z(z = y → φ)
→ ∀x∀z(z = y → φ))) |
3 | 2 | aecoms 1947 |
. . . . 5
⊢ (∀x x = z →
(∀z∀z(z = y → φ)
→ ∀x∀z(z = y → φ))) |
4 | 1, 3 | syl5 28 |
. . . 4
⊢ (∀x x = z →
(∀z(z = y → φ)
→ ∀x∀z(z = y → φ))) |
5 | 4 | a1d 22 |
. . 3
⊢ (∀x x = z →
(¬ ∀x x = y → (∀z(z = y →
φ) → ∀x∀z(z = y →
φ)))) |
6 | | hbnae 1955 |
. . . . . 6
⊢ (¬ ∀x x = z →
∀z
¬ ∀x x = z) |
7 | | hbnae 1955 |
. . . . . 6
⊢ (¬ ∀x x = y →
∀z
¬ ∀x x = y) |
8 | 6, 7 | hban 1828 |
. . . . 5
⊢ ((¬ ∀x x = z ∧ ¬ ∀x x = y) →
∀z(¬ ∀x x = z ∧ ¬ ∀x x = y)) |
9 | | hbnae 1955 |
. . . . . . 7
⊢ (¬ ∀x x = z →
∀x
¬ ∀x x = z) |
10 | | hbnae 1955 |
. . . . . . 7
⊢ (¬ ∀x x = y →
∀x
¬ ∀x x = y) |
11 | 9, 10 | hban 1828 |
. . . . . 6
⊢ ((¬ ∀x x = z ∧ ¬ ∀x x = y) →
∀x(¬ ∀x x = z ∧ ¬ ∀x x = y)) |
12 | | ax12o 1934 |
. . . . . . 7
⊢ (¬ ∀x x = z →
(¬ ∀x x = y → (z =
y → ∀x z = y))) |
13 | 12 | imp 418 |
. . . . . 6
⊢ ((¬ ∀x x = z ∧ ¬ ∀x x = y) →
(z = y
→ ∀x z = y)) |
14 | | dvelimh.1 |
. . . . . . 7
⊢ (φ → ∀xφ) |
15 | 14 | a1i 10 |
. . . . . 6
⊢ ((¬ ∀x x = z ∧ ¬ ∀x x = y) →
(φ → ∀xφ)) |
16 | 11, 13, 15 | hbimd 1815 |
. . . . 5
⊢ ((¬ ∀x x = z ∧ ¬ ∀x x = y) →
((z = y
→ φ) → ∀x(z = y →
φ))) |
17 | 8, 16 | hbald 1740 |
. . . 4
⊢ ((¬ ∀x x = z ∧ ¬ ∀x x = y) →
(∀z(z = y → φ)
→ ∀x∀z(z = y → φ))) |
18 | 17 | ex 423 |
. . 3
⊢ (¬ ∀x x = z →
(¬ ∀x x = y → (∀z(z = y →
φ) → ∀x∀z(z = y →
φ)))) |
19 | 5, 18 | pm2.61i 156 |
. 2
⊢ (¬ ∀x x = y →
(∀z(z = y → φ)
→ ∀x∀z(z = y → φ))) |
20 | | dvelimh.2 |
. . 3
⊢ (ψ → ∀zψ) |
21 | | dvelimh.3 |
. . 3
⊢ (z = y →
(φ ↔ ψ)) |
22 | 20, 21 | equsalh 1961 |
. 2
⊢ (∀z(z = y →
φ) ↔ ψ) |
23 | 22 | albii 1566 |
. 2
⊢ (∀x∀z(z = y →
φ) ↔ ∀xψ) |
24 | 19, 22, 23 | 3imtr3g 260 |
1
⊢ (¬ ∀x x = y →
(ψ → ∀xψ)) |