Proof of Theorem xpsfrnel
| Step | Hyp | Ref
| Expression |
| 1 | | elixp2 8920 |
. 2
⊢ (𝐺 ∈ X𝑘 ∈
2o if(𝑘 =
∅, 𝐴, 𝐵) ↔ (𝐺 ∈ V ∧ 𝐺 Fn 2o ∧ ∀𝑘 ∈ 2o (𝐺‘𝑘) ∈ if(𝑘 = ∅, 𝐴, 𝐵))) |
| 2 | | 3ancoma 1097 |
. . 3
⊢ ((𝐺 ∈ V ∧ 𝐺 Fn 2o ∧
∀𝑘 ∈
2o (𝐺‘𝑘) ∈ if(𝑘 = ∅, 𝐴, 𝐵)) ↔ (𝐺 Fn 2o ∧ 𝐺 ∈ V ∧ ∀𝑘 ∈ 2o (𝐺‘𝑘) ∈ if(𝑘 = ∅, 𝐴, 𝐵))) |
| 3 | | 2onn 8659 |
. . . . . . . . . 10
⊢
2o ∈ ω |
| 4 | | nnfi 9186 |
. . . . . . . . . 10
⊢
(2o ∈ ω → 2o ∈
Fin) |
| 5 | 3, 4 | ax-mp 5 |
. . . . . . . . 9
⊢
2o ∈ Fin |
| 6 | | fnfi 9197 |
. . . . . . . . 9
⊢ ((𝐺 Fn 2o ∧
2o ∈ Fin) → 𝐺 ∈ Fin) |
| 7 | 5, 6 | mpan2 691 |
. . . . . . . 8
⊢ (𝐺 Fn 2o → 𝐺 ∈ Fin) |
| 8 | 7 | elexd 3488 |
. . . . . . 7
⊢ (𝐺 Fn 2o → 𝐺 ∈ V) |
| 9 | 8 | biantrurd 532 |
. . . . . 6
⊢ (𝐺 Fn 2o →
(∀𝑘 ∈
2o (𝐺‘𝑘) ∈ if(𝑘 = ∅, 𝐴, 𝐵) ↔ (𝐺 ∈ V ∧ ∀𝑘 ∈ 2o (𝐺‘𝑘) ∈ if(𝑘 = ∅, 𝐴, 𝐵)))) |
| 10 | | df2o3 8493 |
. . . . . . . 8
⊢
2o = {∅, 1o} |
| 11 | 10 | raleqi 3307 |
. . . . . . 7
⊢
(∀𝑘 ∈
2o (𝐺‘𝑘) ∈ if(𝑘 = ∅, 𝐴, 𝐵) ↔ ∀𝑘 ∈ {∅, 1o} (𝐺‘𝑘) ∈ if(𝑘 = ∅, 𝐴, 𝐵)) |
| 12 | | 0ex 5282 |
. . . . . . . 8
⊢ ∅
∈ V |
| 13 | | 1oex 8495 |
. . . . . . . 8
⊢
1o ∈ V |
| 14 | | fveq2 6881 |
. . . . . . . . 9
⊢ (𝑘 = ∅ → (𝐺‘𝑘) = (𝐺‘∅)) |
| 15 | | iftrue 4511 |
. . . . . . . . 9
⊢ (𝑘 = ∅ → if(𝑘 = ∅, 𝐴, 𝐵) = 𝐴) |
| 16 | 14, 15 | eleq12d 2829 |
. . . . . . . 8
⊢ (𝑘 = ∅ → ((𝐺‘𝑘) ∈ if(𝑘 = ∅, 𝐴, 𝐵) ↔ (𝐺‘∅) ∈ 𝐴)) |
| 17 | | fveq2 6881 |
. . . . . . . . 9
⊢ (𝑘 = 1o → (𝐺‘𝑘) = (𝐺‘1o)) |
| 18 | | 1n0 8505 |
. . . . . . . . . . 11
⊢
1o ≠ ∅ |
| 19 | | neeq1 2995 |
. . . . . . . . . . 11
⊢ (𝑘 = 1o → (𝑘 ≠ ∅ ↔
1o ≠ ∅)) |
| 20 | 18, 19 | mpbiri 258 |
. . . . . . . . . 10
⊢ (𝑘 = 1o → 𝑘 ≠ ∅) |
| 21 | | ifnefalse 4517 |
. . . . . . . . . 10
⊢ (𝑘 ≠ ∅ → if(𝑘 = ∅, 𝐴, 𝐵) = 𝐵) |
| 22 | 20, 21 | syl 17 |
. . . . . . . . 9
⊢ (𝑘 = 1o → if(𝑘 = ∅, 𝐴, 𝐵) = 𝐵) |
| 23 | 17, 22 | eleq12d 2829 |
. . . . . . . 8
⊢ (𝑘 = 1o → ((𝐺‘𝑘) ∈ if(𝑘 = ∅, 𝐴, 𝐵) ↔ (𝐺‘1o) ∈ 𝐵)) |
| 24 | 12, 13, 16, 23 | ralpr 4681 |
. . . . . . 7
⊢
(∀𝑘 ∈
{∅, 1o} (𝐺‘𝑘) ∈ if(𝑘 = ∅, 𝐴, 𝐵) ↔ ((𝐺‘∅) ∈ 𝐴 ∧ (𝐺‘1o) ∈ 𝐵)) |
| 25 | 11, 24 | bitri 275 |
. . . . . 6
⊢
(∀𝑘 ∈
2o (𝐺‘𝑘) ∈ if(𝑘 = ∅, 𝐴, 𝐵) ↔ ((𝐺‘∅) ∈ 𝐴 ∧ (𝐺‘1o) ∈ 𝐵)) |
| 26 | 9, 25 | bitr3di 286 |
. . . . 5
⊢ (𝐺 Fn 2o → ((𝐺 ∈ V ∧ ∀𝑘 ∈ 2o (𝐺‘𝑘) ∈ if(𝑘 = ∅, 𝐴, 𝐵)) ↔ ((𝐺‘∅) ∈ 𝐴 ∧ (𝐺‘1o) ∈ 𝐵))) |
| 27 | 26 | pm5.32i 574 |
. . . 4
⊢ ((𝐺 Fn 2o ∧ (𝐺 ∈ V ∧ ∀𝑘 ∈ 2o (𝐺‘𝑘) ∈ if(𝑘 = ∅, 𝐴, 𝐵))) ↔ (𝐺 Fn 2o ∧ ((𝐺‘∅) ∈ 𝐴 ∧ (𝐺‘1o) ∈ 𝐵))) |
| 28 | | 3anass 1094 |
. . . 4
⊢ ((𝐺 Fn 2o ∧ 𝐺 ∈ V ∧ ∀𝑘 ∈ 2o (𝐺‘𝑘) ∈ if(𝑘 = ∅, 𝐴, 𝐵)) ↔ (𝐺 Fn 2o ∧ (𝐺 ∈ V ∧ ∀𝑘 ∈ 2o (𝐺‘𝑘) ∈ if(𝑘 = ∅, 𝐴, 𝐵)))) |
| 29 | | 3anass 1094 |
. . . 4
⊢ ((𝐺 Fn 2o ∧ (𝐺‘∅) ∈ 𝐴 ∧ (𝐺‘1o) ∈ 𝐵) ↔ (𝐺 Fn 2o ∧ ((𝐺‘∅) ∈ 𝐴 ∧ (𝐺‘1o) ∈ 𝐵))) |
| 30 | 27, 28, 29 | 3bitr4i 303 |
. . 3
⊢ ((𝐺 Fn 2o ∧ 𝐺 ∈ V ∧ ∀𝑘 ∈ 2o (𝐺‘𝑘) ∈ if(𝑘 = ∅, 𝐴, 𝐵)) ↔ (𝐺 Fn 2o ∧ (𝐺‘∅) ∈ 𝐴 ∧ (𝐺‘1o) ∈ 𝐵)) |
| 31 | 2, 30 | bitri 275 |
. 2
⊢ ((𝐺 ∈ V ∧ 𝐺 Fn 2o ∧
∀𝑘 ∈
2o (𝐺‘𝑘) ∈ if(𝑘 = ∅, 𝐴, 𝐵)) ↔ (𝐺 Fn 2o ∧ (𝐺‘∅) ∈ 𝐴 ∧ (𝐺‘1o) ∈ 𝐵)) |
| 32 | 1, 31 | bitri 275 |
1
⊢ (𝐺 ∈ X𝑘 ∈
2o if(𝑘 =
∅, 𝐴, 𝐵) ↔ (𝐺 Fn 2o ∧ (𝐺‘∅) ∈ 𝐴 ∧ (𝐺‘1o) ∈ 𝐵)) |