Proof of Theorem ralxp
| Step | Hyp | Ref
| Expression |
| 1 | | ralxp.1 |
. . . . . . 7
⊢ (x =
〈y, z〉 → (φ ↔ ψ)) |
| 2 | 1 | rcla4v 1402 |
. . . . . 6
⊢ (∀x ∈ (A
× B)φ → (〈y, z〉
∈ (A × B) → ψ)) |
| 3 | | visset 1350 |
. . . . . . 7
⊢ z
∈ V |
| 4 | 3 | opelxp 2452 |
. . . . . 6
⊢ (〈y, z〉
∈ (A × B) ↔ (y
∈ A ∧ z ∈ B)) |
| 5 | 2, 4 | syl5ibr 182 |
. . . . 5
⊢ (∀x ∈ (A
× B)φ → ((y ∈ A ∧
z ∈ B) → ψ)) |
| 6 | 5 | exp3a 292 |
. . . 4
⊢ (∀x ∈ (A
× B)φ → (y ∈ A
→ (z ∈ B → ψ))) |
| 7 | 6 | r19.21adv 1262 |
. . 3
⊢ (∀x ∈ (A
× B)φ → (y ∈ A
→ ∀z ∈ B ψ)) |
| 8 | 7 | r19.21aiv 1259 |
. 2
⊢ (∀x ∈ (A
× B)φ → ∀y ∈ A
∀z ∈ B ψ) |
| 9 | | elxp 2442 |
. . . . . 6
⊢ (x
∈ (A × B) ↔ ∃y∃z(x =
〈y, z〉 ∧ (y
∈ A ∧ z ∈ B))) |
| 10 | | pm3.26 256 |
. . . . . . . 8
⊢ ((x =
〈y, z〉 ∧ (y
∈ A ∧ z ∈ B))
→ x = 〈y, z〉) |
| 11 | 10 | 19.22i 723 |
. . . . . . 7
⊢ (∃z(x =
〈y, z〉 ∧ (y
∈ A ∧ z ∈ B))
→ ∃z x = 〈y,
z〉) |
| 12 | 11 | 19.22i 723 |
. . . . . 6
⊢ (∃y∃z(x =
〈y, z〉 ∧ (y
∈ A ∧ z ∈ B))
→ ∃y∃z x =
〈y, z〉) |
| 13 | 9, 12 | sylbi 174 |
. . . . 5
⊢ (x
∈ (A × B) → ∃y∃z
x = 〈y, z〉) |
| 14 | | hbra1 1237 |
. . . . . . 7
⊢ (∀y ∈ A
∀z ∈ B ψ →
∀y∀y ∈ A
∀z ∈ B ψ) |
| 15 | | ax-17 925 |
. . . . . . 7
⊢ ((x
∈ (A × B) → φ)
→ ∀y(x ∈ (A
× B) → φ)) |
| 16 | 14, 15 | hbim 702 |
. . . . . 6
⊢ ((∀y ∈ A
∀z ∈ B ψ →
(x ∈ (A × B)
→ φ)) → ∀y(∀y
∈ A ∀z ∈ B ψ → (x ∈ (A
× B) → φ))) |
| 17 | | ax-17 925 |
. . . . . . . . 9
⊢ (y
∈ A → ∀z y ∈
A) |
| 18 | | hbra1 1237 |
. . . . . . . . 9
⊢ (∀z ∈ B ψ → ∀z∀z
∈ B ψ) |
| 19 | 17, 18 | hbral 1236 |
. . . . . . . 8
⊢ (∀y ∈ A
∀z ∈ B ψ →
∀z∀y ∈ A
∀z ∈ B ψ) |
| 20 | | ax-17 925 |
. . . . . . . 8
⊢ ((x
∈ (A × B) → φ)
→ ∀z(x ∈ (A
× B) → φ)) |
| 21 | 19, 20 | hbim 702 |
. . . . . . 7
⊢ ((∀y ∈ A
∀z ∈ B ψ →
(x ∈ (A × B)
→ φ)) → ∀z(∀y
∈ A ∀z ∈ B ψ → (x ∈ (A
× B) → φ))) |
| 22 | | eleq1 1149 |
. . . . . . . . . 10
⊢ (x =
〈y, z〉 → (x ∈ (A
× B) ↔ 〈y, z〉
∈ (A × B))) |
| 23 | 22, 4 | syl6bb 414 |
. . . . . . . . 9
⊢ (x =
〈y, z〉 → (x ∈ (A
× B) ↔ (y ∈ A ∧
z ∈ B))) |
| 24 | 23, 1 | imbi12d 474 |
. . . . . . . 8
⊢ (x =
〈y, z〉 → ((x ∈ (A
× B) → φ) ↔ ((y ∈ A ∧
z ∈ B) → ψ))) |
| 25 | | ra42 1245 |
. . . . . . . 8
⊢ (∀y ∈ A
∀z ∈ B ψ →
((y ∈ A ∧ z ∈
B) → ψ)) |
| 26 | 24, 25 | syl5bir 184 |
. . . . . . 7
⊢ (x =
〈y, z〉 → (∀y ∈ A
∀z ∈ B ψ →
(x ∈ (A × B)
→ φ))) |
| 27 | 21, 26 | 19.23ai 746 |
. . . . . 6
⊢ (∃z x =
〈y, z〉 → (∀y ∈ A
∀z ∈ B ψ →
(x ∈ (A × B)
→ φ))) |
| 28 | 16, 27 | 19.23ai 746 |
. . . . 5
⊢ (∃y∃z
x = 〈y, z〉
→ (∀y ∈ A ∀z
∈ B ψ → (x ∈ (A
× B) → φ))) |
| 29 | 13, 28 | syl 12 |
. . . 4
⊢ (x
∈ (A × B) → (∀y ∈ A
∀z ∈ B ψ →
(x ∈ (A × B)
→ φ))) |
| 30 | 29 | pm2.43b 61 |
. . 3
⊢ (∀y ∈ A
∀z ∈ B ψ →
(x ∈ (A × B)
→ φ)) |
| 31 | 30 | r19.21aiv 1259 |
. 2
⊢ (∀y ∈ A
∀z ∈ B ψ →
∀x ∈ (A × B)φ) |
| 32 | 8, 31 | impbi 139 |
1
⊢ (∀x ∈ (A
× B)φ ↔ ∀y ∈ A
∀z ∈ B ψ) |