Proof of Theorem rspc2gv
Step | Hyp | Ref
| Expression |
1 | | df-ral 3066 |
. 2
⊢
(∀𝑥 ∈
𝑉 ∀𝑦 ∈ 𝑊 𝜑 ↔ ∀𝑥(𝑥 ∈ 𝑉 → ∀𝑦 ∈ 𝑊 𝜑)) |
2 | | df-ral 3066 |
. . . . 5
⊢
(∀𝑦 ∈
𝑊 𝜑 ↔ ∀𝑦(𝑦 ∈ 𝑊 → 𝜑)) |
3 | 2 | imbi2i 339 |
. . . 4
⊢ ((𝑥 ∈ 𝑉 → ∀𝑦 ∈ 𝑊 𝜑) ↔ (𝑥 ∈ 𝑉 → ∀𝑦(𝑦 ∈ 𝑊 → 𝜑))) |
4 | 3 | albii 1827 |
. . 3
⊢
(∀𝑥(𝑥 ∈ 𝑉 → ∀𝑦 ∈ 𝑊 𝜑) ↔ ∀𝑥(𝑥 ∈ 𝑉 → ∀𝑦(𝑦 ∈ 𝑊 → 𝜑))) |
5 | | 19.21v 1947 |
. . . . . 6
⊢
(∀𝑦(𝑥 ∈ 𝑉 → (𝑦 ∈ 𝑊 → 𝜑)) ↔ (𝑥 ∈ 𝑉 → ∀𝑦(𝑦 ∈ 𝑊 → 𝜑))) |
6 | 5 | bicomi 227 |
. . . . 5
⊢ ((𝑥 ∈ 𝑉 → ∀𝑦(𝑦 ∈ 𝑊 → 𝜑)) ↔ ∀𝑦(𝑥 ∈ 𝑉 → (𝑦 ∈ 𝑊 → 𝜑))) |
7 | 6 | albii 1827 |
. . . 4
⊢
(∀𝑥(𝑥 ∈ 𝑉 → ∀𝑦(𝑦 ∈ 𝑊 → 𝜑)) ↔ ∀𝑥∀𝑦(𝑥 ∈ 𝑉 → (𝑦 ∈ 𝑊 → 𝜑))) |
8 | | impexp 454 |
. . . . . . 7
⊢ (((𝑥 ∈ 𝑉 ∧ 𝑦 ∈ 𝑊) → 𝜑) ↔ (𝑥 ∈ 𝑉 → (𝑦 ∈ 𝑊 → 𝜑))) |
9 | | eleq1 2825 |
. . . . . . . . 9
⊢ (𝑥 = 𝐴 → (𝑥 ∈ 𝑉 ↔ 𝐴 ∈ 𝑉)) |
10 | | eleq1 2825 |
. . . . . . . . 9
⊢ (𝑦 = 𝐵 → (𝑦 ∈ 𝑊 ↔ 𝐵 ∈ 𝑊)) |
11 | 9, 10 | bi2anan9 639 |
. . . . . . . 8
⊢ ((𝑥 = 𝐴 ∧ 𝑦 = 𝐵) → ((𝑥 ∈ 𝑉 ∧ 𝑦 ∈ 𝑊) ↔ (𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊))) |
12 | | rspc2gv.1 |
. . . . . . . 8
⊢ ((𝑥 = 𝐴 ∧ 𝑦 = 𝐵) → (𝜑 ↔ 𝜓)) |
13 | 11, 12 | imbi12d 348 |
. . . . . . 7
⊢ ((𝑥 = 𝐴 ∧ 𝑦 = 𝐵) → (((𝑥 ∈ 𝑉 ∧ 𝑦 ∈ 𝑊) → 𝜑) ↔ ((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) → 𝜓))) |
14 | 8, 13 | bitr3id 288 |
. . . . . 6
⊢ ((𝑥 = 𝐴 ∧ 𝑦 = 𝐵) → ((𝑥 ∈ 𝑉 → (𝑦 ∈ 𝑊 → 𝜑)) ↔ ((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) → 𝜓))) |
15 | 14 | spc2gv 3515 |
. . . . 5
⊢ ((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) → (∀𝑥∀𝑦(𝑥 ∈ 𝑉 → (𝑦 ∈ 𝑊 → 𝜑)) → ((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) → 𝜓))) |
16 | 15 | pm2.43a 54 |
. . . 4
⊢ ((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) → (∀𝑥∀𝑦(𝑥 ∈ 𝑉 → (𝑦 ∈ 𝑊 → 𝜑)) → 𝜓)) |
17 | 7, 16 | syl5bi 245 |
. . 3
⊢ ((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) → (∀𝑥(𝑥 ∈ 𝑉 → ∀𝑦(𝑦 ∈ 𝑊 → 𝜑)) → 𝜓)) |
18 | 4, 17 | syl5bi 245 |
. 2
⊢ ((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) → (∀𝑥(𝑥 ∈ 𝑉 → ∀𝑦 ∈ 𝑊 𝜑) → 𝜓)) |
19 | 1, 18 | syl5bi 245 |
1
⊢ ((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) → (∀𝑥 ∈ 𝑉 ∀𝑦 ∈ 𝑊 𝜑 → 𝜓)) |