Proof of Theorem 2uasbanh
Step | Hyp | Ref
| Expression |
1 | | simpl 483 |
. . . . 5
⊢ (((𝑥 = 𝑢 ∧ 𝑦 = 𝑣) ∧ (𝜑 ∧ 𝜓)) → (𝑥 = 𝑢 ∧ 𝑦 = 𝑣)) |
2 | | simprl 768 |
. . . . 5
⊢ (((𝑥 = 𝑢 ∧ 𝑦 = 𝑣) ∧ (𝜑 ∧ 𝜓)) → 𝜑) |
3 | 1, 2 | jca 512 |
. . . 4
⊢ (((𝑥 = 𝑢 ∧ 𝑦 = 𝑣) ∧ (𝜑 ∧ 𝜓)) → ((𝑥 = 𝑢 ∧ 𝑦 = 𝑣) ∧ 𝜑)) |
4 | 3 | 2eximi 1838 |
. . 3
⊢
(∃𝑥∃𝑦((𝑥 = 𝑢 ∧ 𝑦 = 𝑣) ∧ (𝜑 ∧ 𝜓)) → ∃𝑥∃𝑦((𝑥 = 𝑢 ∧ 𝑦 = 𝑣) ∧ 𝜑)) |
5 | | simprr 770 |
. . . . 5
⊢ (((𝑥 = 𝑢 ∧ 𝑦 = 𝑣) ∧ (𝜑 ∧ 𝜓)) → 𝜓) |
6 | 1, 5 | jca 512 |
. . . 4
⊢ (((𝑥 = 𝑢 ∧ 𝑦 = 𝑣) ∧ (𝜑 ∧ 𝜓)) → ((𝑥 = 𝑢 ∧ 𝑦 = 𝑣) ∧ 𝜓)) |
7 | 6 | 2eximi 1838 |
. . 3
⊢
(∃𝑥∃𝑦((𝑥 = 𝑢 ∧ 𝑦 = 𝑣) ∧ (𝜑 ∧ 𝜓)) → ∃𝑥∃𝑦((𝑥 = 𝑢 ∧ 𝑦 = 𝑣) ∧ 𝜓)) |
8 | 4, 7 | jca 512 |
. 2
⊢
(∃𝑥∃𝑦((𝑥 = 𝑢 ∧ 𝑦 = 𝑣) ∧ (𝜑 ∧ 𝜓)) → (∃𝑥∃𝑦((𝑥 = 𝑢 ∧ 𝑦 = 𝑣) ∧ 𝜑) ∧ ∃𝑥∃𝑦((𝑥 = 𝑢 ∧ 𝑦 = 𝑣) ∧ 𝜓))) |
9 | | 2uasbanh.1 |
. . 3
⊢ (𝜒 ↔ (∃𝑥∃𝑦((𝑥 = 𝑢 ∧ 𝑦 = 𝑣) ∧ 𝜑) ∧ ∃𝑥∃𝑦((𝑥 = 𝑢 ∧ 𝑦 = 𝑣) ∧ 𝜓))) |
10 | 9 | simplbi 498 |
. . . . . 6
⊢ (𝜒 → ∃𝑥∃𝑦((𝑥 = 𝑢 ∧ 𝑦 = 𝑣) ∧ 𝜑)) |
11 | | simpl 483 |
. . . . . . . . . 10
⊢ (((𝑥 = 𝑢 ∧ 𝑦 = 𝑣) ∧ 𝜑) → (𝑥 = 𝑢 ∧ 𝑦 = 𝑣)) |
12 | 11 | 2eximi 1838 |
. . . . . . . . 9
⊢
(∃𝑥∃𝑦((𝑥 = 𝑢 ∧ 𝑦 = 𝑣) ∧ 𝜑) → ∃𝑥∃𝑦(𝑥 = 𝑢 ∧ 𝑦 = 𝑣)) |
13 | 10, 12 | syl 17 |
. . . . . . . 8
⊢ (𝜒 → ∃𝑥∃𝑦(𝑥 = 𝑢 ∧ 𝑦 = 𝑣)) |
14 | | ax6e2ndeq 42179 |
. . . . . . . 8
⊢ ((¬
∀𝑥 𝑥 = 𝑦 ∨ 𝑢 = 𝑣) ↔ ∃𝑥∃𝑦(𝑥 = 𝑢 ∧ 𝑦 = 𝑣)) |
15 | 13, 14 | sylibr 233 |
. . . . . . 7
⊢ (𝜒 → (¬ ∀𝑥 𝑥 = 𝑦 ∨ 𝑢 = 𝑣)) |
16 | | 2sb5nd 42180 |
. . . . . . 7
⊢ ((¬
∀𝑥 𝑥 = 𝑦 ∨ 𝑢 = 𝑣) → ([𝑢 / 𝑥][𝑣 / 𝑦]𝜑 ↔ ∃𝑥∃𝑦((𝑥 = 𝑢 ∧ 𝑦 = 𝑣) ∧ 𝜑))) |
17 | 15, 16 | syl 17 |
. . . . . 6
⊢ (𝜒 → ([𝑢 / 𝑥][𝑣 / 𝑦]𝜑 ↔ ∃𝑥∃𝑦((𝑥 = 𝑢 ∧ 𝑦 = 𝑣) ∧ 𝜑))) |
18 | 10, 17 | mpbird 256 |
. . . . 5
⊢ (𝜒 → [𝑢 / 𝑥][𝑣 / 𝑦]𝜑) |
19 | 9 | simprbi 497 |
. . . . . 6
⊢ (𝜒 → ∃𝑥∃𝑦((𝑥 = 𝑢 ∧ 𝑦 = 𝑣) ∧ 𝜓)) |
20 | | 2sb5nd 42180 |
. . . . . . 7
⊢ ((¬
∀𝑥 𝑥 = 𝑦 ∨ 𝑢 = 𝑣) → ([𝑢 / 𝑥][𝑣 / 𝑦]𝜓 ↔ ∃𝑥∃𝑦((𝑥 = 𝑢 ∧ 𝑦 = 𝑣) ∧ 𝜓))) |
21 | 15, 20 | syl 17 |
. . . . . 6
⊢ (𝜒 → ([𝑢 / 𝑥][𝑣 / 𝑦]𝜓 ↔ ∃𝑥∃𝑦((𝑥 = 𝑢 ∧ 𝑦 = 𝑣) ∧ 𝜓))) |
22 | 19, 21 | mpbird 256 |
. . . . 5
⊢ (𝜒 → [𝑢 / 𝑥][𝑣 / 𝑦]𝜓) |
23 | | sban 2083 |
. . . . . . 7
⊢ ([𝑣 / 𝑦](𝜑 ∧ 𝜓) ↔ ([𝑣 / 𝑦]𝜑 ∧ [𝑣 / 𝑦]𝜓)) |
24 | 23 | sbbii 2079 |
. . . . . 6
⊢ ([𝑢 / 𝑥][𝑣 / 𝑦](𝜑 ∧ 𝜓) ↔ [𝑢 / 𝑥]([𝑣 / 𝑦]𝜑 ∧ [𝑣 / 𝑦]𝜓)) |
25 | | sban 2083 |
. . . . . 6
⊢ ([𝑢 / 𝑥]([𝑣 / 𝑦]𝜑 ∧ [𝑣 / 𝑦]𝜓) ↔ ([𝑢 / 𝑥][𝑣 / 𝑦]𝜑 ∧ [𝑢 / 𝑥][𝑣 / 𝑦]𝜓)) |
26 | 24, 25 | bitri 274 |
. . . . 5
⊢ ([𝑢 / 𝑥][𝑣 / 𝑦](𝜑 ∧ 𝜓) ↔ ([𝑢 / 𝑥][𝑣 / 𝑦]𝜑 ∧ [𝑢 / 𝑥][𝑣 / 𝑦]𝜓)) |
27 | 18, 22, 26 | sylanbrc 583 |
. . . 4
⊢ (𝜒 → [𝑢 / 𝑥][𝑣 / 𝑦](𝜑 ∧ 𝜓)) |
28 | | 2sb5nd 42180 |
. . . . 5
⊢ ((¬
∀𝑥 𝑥 = 𝑦 ∨ 𝑢 = 𝑣) → ([𝑢 / 𝑥][𝑣 / 𝑦](𝜑 ∧ 𝜓) ↔ ∃𝑥∃𝑦((𝑥 = 𝑢 ∧ 𝑦 = 𝑣) ∧ (𝜑 ∧ 𝜓)))) |
29 | 15, 28 | syl 17 |
. . . 4
⊢ (𝜒 → ([𝑢 / 𝑥][𝑣 / 𝑦](𝜑 ∧ 𝜓) ↔ ∃𝑥∃𝑦((𝑥 = 𝑢 ∧ 𝑦 = 𝑣) ∧ (𝜑 ∧ 𝜓)))) |
30 | 27, 29 | mpbid 231 |
. . 3
⊢ (𝜒 → ∃𝑥∃𝑦((𝑥 = 𝑢 ∧ 𝑦 = 𝑣) ∧ (𝜑 ∧ 𝜓))) |
31 | 9, 30 | sylbir 234 |
. 2
⊢
((∃𝑥∃𝑦((𝑥 = 𝑢 ∧ 𝑦 = 𝑣) ∧ 𝜑) ∧ ∃𝑥∃𝑦((𝑥 = 𝑢 ∧ 𝑦 = 𝑣) ∧ 𝜓)) → ∃𝑥∃𝑦((𝑥 = 𝑢 ∧ 𝑦 = 𝑣) ∧ (𝜑 ∧ 𝜓))) |
32 | 8, 31 | impbii 208 |
1
⊢
(∃𝑥∃𝑦((𝑥 = 𝑢 ∧ 𝑦 = 𝑣) ∧ (𝜑 ∧ 𝜓)) ↔ (∃𝑥∃𝑦((𝑥 = 𝑢 ∧ 𝑦 = 𝑣) ∧ 𝜑) ∧ ∃𝑥∃𝑦((𝑥 = 𝑢 ∧ 𝑦 = 𝑣) ∧ 𝜓))) |