Proof of Theorem dvelimv
| Step | Hyp | Ref
| Expression |
| 1 | | ax-17 1616 |
. . . . . 6
⊢ (ψ → ∀zψ) |
| 2 | 1 | a1d 22 |
. . . . . 6
⊢ (ψ → (z = y →
∀zψ)) |
| 3 | 1, 2 | alrimih 1565 |
. . . . 5
⊢ (ψ → ∀z(z = y →
∀zψ)) |
| 4 | | sp 1747 |
. . . . . . . 8
⊢ (∀zψ → ψ) |
| 5 | | dvelimv.1 |
. . . . . . . 8
⊢ (z = y →
(φ ↔ ψ)) |
| 6 | 4, 5 | syl5ibr 212 |
. . . . . . 7
⊢ (z = y →
(∀zψ →
φ)) |
| 7 | 6 | a2i 12 |
. . . . . 6
⊢ ((z = y →
∀zψ) → (z = y →
φ)) |
| 8 | 7 | alimi 1559 |
. . . . 5
⊢ (∀z(z = y →
∀zψ) → ∀z(z = y →
φ)) |
| 9 | 3, 8 | syl 15 |
. . . 4
⊢ (ψ → ∀z(z = y →
φ)) |
| 10 | | ax10lem3 1938 |
. . . . . . . 8
⊢ (∀z z = x →
∀x
x = z) |
| 11 | 10 | con3i 127 |
. . . . . . 7
⊢ (¬ ∀x x = z →
¬ ∀z z = x) |
| 12 | | hbn1 1730 |
. . . . . . . 8
⊢ (¬ ∀z z = x →
∀z
¬ ∀z z = x) |
| 13 | | ax10lem3 1938 |
. . . . . . . . 9
⊢ (∀x x = z →
∀z
z = x) |
| 14 | 13 | con3i 127 |
. . . . . . . 8
⊢ (¬ ∀z z = x →
¬ ∀x x = z) |
| 15 | 12, 14 | alrimih 1565 |
. . . . . . 7
⊢ (¬ ∀z z = x →
∀z
¬ ∀x x = z) |
| 16 | 11, 15 | syl 15 |
. . . . . 6
⊢ (¬ ∀x x = z →
∀z
¬ ∀x x = z) |
| 17 | | ax-17 1616 |
. . . . . 6
⊢ (¬ ∀x x = y →
∀z
¬ ∀x x = y) |
| 18 | 16, 17 | hban 1828 |
. . . . 5
⊢ ((¬ ∀x x = z ∧ ¬ ∀x x = y) →
∀z(¬ ∀x x = z ∧ ¬ ∀x x = y)) |
| 19 | | hbn1 1730 |
. . . . . . 7
⊢ (¬ ∀x x = z →
∀x
¬ ∀x x = z) |
| 20 | | hbn1 1730 |
. . . . . . 7
⊢ (¬ ∀x x = y →
∀x
¬ ∀x x = y) |
| 21 | 19, 20 | hban 1828 |
. . . . . 6
⊢ ((¬ ∀x x = z ∧ ¬ ∀x x = y) →
∀x(¬ ∀x x = z ∧ ¬ ∀x x = y)) |
| 22 | | ax12o 1934 |
. . . . . . 7
⊢ (¬ ∀x x = z →
(¬ ∀x x = y → (z =
y → ∀x z = y))) |
| 23 | 22 | imp 418 |
. . . . . 6
⊢ ((¬ ∀x x = z ∧ ¬ ∀x x = y) →
(z = y
→ ∀x z = y)) |
| 24 | | a17d 1617 |
. . . . . 6
⊢ ((¬ ∀x x = z ∧ ¬ ∀x x = y) →
(φ → ∀xφ)) |
| 25 | 21, 23, 24 | hbimd 1815 |
. . . . 5
⊢ ((¬ ∀x x = z ∧ ¬ ∀x x = y) →
((z = y
→ φ) → ∀x(z = y →
φ))) |
| 26 | 18, 25 | hbald 1740 |
. . . 4
⊢ ((¬ ∀x x = z ∧ ¬ ∀x x = y) →
(∀z(z = y → φ)
→ ∀x∀z(z = y → φ))) |
| 27 | 5 | biimpd 198 |
. . . . . . . . 9
⊢ (z = y →
(φ → ψ)) |
| 28 | 27 | a2i 12 |
. . . . . . . 8
⊢ ((z = y →
φ) → (z = y →
ψ)) |
| 29 | 28 | alimi 1559 |
. . . . . . 7
⊢ (∀z(z = y →
φ) → ∀z(z = y →
ψ)) |
| 30 | | ax9v 1655 |
. . . . . . . 8
⊢ ¬ ∀z ¬
z = y |
| 31 | | con3 126 |
. . . . . . . . 9
⊢ ((z = y →
ψ) → (¬ ψ → ¬ z = y)) |
| 32 | 31 | al2imi 1561 |
. . . . . . . 8
⊢ (∀z(z = y →
ψ) → (∀z ¬
ψ → ∀z ¬
z = y)) |
| 33 | 30, 32 | mtoi 169 |
. . . . . . 7
⊢ (∀z(z = y →
ψ) → ¬ ∀z ¬
ψ) |
| 34 | 29, 33 | syl 15 |
. . . . . 6
⊢ (∀z(z = y →
φ) → ¬ ∀z ¬
ψ) |
| 35 | | ax-17 1616 |
. . . . . 6
⊢ (¬ ψ → ∀z ¬
ψ) |
| 36 | 34, 35 | nsyl2 119 |
. . . . 5
⊢ (∀z(z = y →
φ) → ψ) |
| 37 | 36 | alimi 1559 |
. . . 4
⊢ (∀x∀z(z = y →
φ) → ∀xψ) |
| 38 | 9, 26, 37 | syl56 30 |
. . 3
⊢ ((¬ ∀x x = z ∧ ¬ ∀x x = y) →
(ψ → ∀xψ)) |
| 39 | 38 | expcom 424 |
. 2
⊢ (¬ ∀x x = y →
(¬ ∀x x = z → (ψ
→ ∀xψ))) |
| 40 | | sp 1747 |
. . . 4
⊢ (∀x x = z →
x = z) |
| 41 | | ax-11 1746 |
. . . 4
⊢ (x = z →
(∀zψ →
∀x(x = z → ψ))) |
| 42 | 40, 1, 41 | syl2im 34 |
. . 3
⊢ (∀x x = z →
(ψ → ∀x(x = z →
ψ))) |
| 43 | | pm2.27 35 |
. . . 4
⊢ (x = z →
((x = z
→ ψ) → ψ)) |
| 44 | 43 | al2imi 1561 |
. . 3
⊢ (∀x x = z →
(∀x(x = z → ψ)
→ ∀xψ)) |
| 45 | 42, 44 | syld 40 |
. 2
⊢ (∀x x = z →
(ψ → ∀xψ)) |
| 46 | 39, 45 | pm2.61d2 152 |
1
⊢ (¬ ∀x x = y →
(ψ → ∀xψ)) |