| Step | Hyp | Ref
| Expression |
| 1 | | pwundif 5021 |
. 2
⊢ 𝒫
(𝑏 ∪ {𝑥}) = ((𝒫 (𝑏 ∪ {𝑥}) ∖ 𝒫 𝑏) ∪ 𝒫 𝑏) |
| 2 | | vex 3203 |
. . . . . . . . 9
⊢ 𝑐 ∈ V |
| 3 | | snex 4908 |
. . . . . . . . 9
⊢ {𝑥} ∈ V |
| 4 | 2, 3 | unex 6956 |
. . . . . . . 8
⊢ (𝑐 ∪ {𝑥}) ∈ V |
| 5 | | pwfilem.1 |
. . . . . . . 8
⊢ 𝐹 = (𝑐 ∈ 𝒫 𝑏 ↦ (𝑐 ∪ {𝑥})) |
| 6 | 4, 5 | fnmpti 6022 |
. . . . . . 7
⊢ 𝐹 Fn 𝒫 𝑏 |
| 7 | | dffn4 6121 |
. . . . . . 7
⊢ (𝐹 Fn 𝒫 𝑏 ↔ 𝐹:𝒫 𝑏–onto→ran 𝐹) |
| 8 | 6, 7 | mpbi 220 |
. . . . . 6
⊢ 𝐹:𝒫 𝑏–onto→ran 𝐹 |
| 9 | | fodomfi 8239 |
. . . . . 6
⊢
((𝒫 𝑏 ∈
Fin ∧ 𝐹:𝒫 𝑏–onto→ran 𝐹) → ran 𝐹 ≼ 𝒫 𝑏) |
| 10 | 8, 9 | mpan2 707 |
. . . . 5
⊢
(𝒫 𝑏 ∈
Fin → ran 𝐹 ≼
𝒫 𝑏) |
| 11 | | domfi 8181 |
. . . . 5
⊢
((𝒫 𝑏 ∈
Fin ∧ ran 𝐹 ≼
𝒫 𝑏) → ran
𝐹 ∈
Fin) |
| 12 | 10, 11 | mpdan 702 |
. . . 4
⊢
(𝒫 𝑏 ∈
Fin → ran 𝐹 ∈
Fin) |
| 13 | | eldifi 3732 |
. . . . . . . . 9
⊢ (𝑑 ∈ (𝒫 (𝑏 ∪ {𝑥}) ∖ 𝒫 𝑏) → 𝑑 ∈ 𝒫 (𝑏 ∪ {𝑥})) |
| 14 | 3 | elpwun 6977 |
. . . . . . . . 9
⊢ (𝑑 ∈ 𝒫 (𝑏 ∪ {𝑥}) ↔ (𝑑 ∖ {𝑥}) ∈ 𝒫 𝑏) |
| 15 | 13, 14 | sylib 208 |
. . . . . . . 8
⊢ (𝑑 ∈ (𝒫 (𝑏 ∪ {𝑥}) ∖ 𝒫 𝑏) → (𝑑 ∖ {𝑥}) ∈ 𝒫 𝑏) |
| 16 | | undif1 4043 |
. . . . . . . . 9
⊢ ((𝑑 ∖ {𝑥}) ∪ {𝑥}) = (𝑑 ∪ {𝑥}) |
| 17 | | elpwunsn 4224 |
. . . . . . . . . . 11
⊢ (𝑑 ∈ (𝒫 (𝑏 ∪ {𝑥}) ∖ 𝒫 𝑏) → 𝑥 ∈ 𝑑) |
| 18 | 17 | snssd 4340 |
. . . . . . . . . 10
⊢ (𝑑 ∈ (𝒫 (𝑏 ∪ {𝑥}) ∖ 𝒫 𝑏) → {𝑥} ⊆ 𝑑) |
| 19 | | ssequn2 3786 |
. . . . . . . . . 10
⊢ ({𝑥} ⊆ 𝑑 ↔ (𝑑 ∪ {𝑥}) = 𝑑) |
| 20 | 18, 19 | sylib 208 |
. . . . . . . . 9
⊢ (𝑑 ∈ (𝒫 (𝑏 ∪ {𝑥}) ∖ 𝒫 𝑏) → (𝑑 ∪ {𝑥}) = 𝑑) |
| 21 | 16, 20 | syl5req 2669 |
. . . . . . . 8
⊢ (𝑑 ∈ (𝒫 (𝑏 ∪ {𝑥}) ∖ 𝒫 𝑏) → 𝑑 = ((𝑑 ∖ {𝑥}) ∪ {𝑥})) |
| 22 | | uneq1 3760 |
. . . . . . . . . 10
⊢ (𝑐 = (𝑑 ∖ {𝑥}) → (𝑐 ∪ {𝑥}) = ((𝑑 ∖ {𝑥}) ∪ {𝑥})) |
| 23 | 22 | eqeq2d 2632 |
. . . . . . . . 9
⊢ (𝑐 = (𝑑 ∖ {𝑥}) → (𝑑 = (𝑐 ∪ {𝑥}) ↔ 𝑑 = ((𝑑 ∖ {𝑥}) ∪ {𝑥}))) |
| 24 | 23 | rspcev 3309 |
. . . . . . . 8
⊢ (((𝑑 ∖ {𝑥}) ∈ 𝒫 𝑏 ∧ 𝑑 = ((𝑑 ∖ {𝑥}) ∪ {𝑥})) → ∃𝑐 ∈ 𝒫 𝑏𝑑 = (𝑐 ∪ {𝑥})) |
| 25 | 15, 21, 24 | syl2anc 693 |
. . . . . . 7
⊢ (𝑑 ∈ (𝒫 (𝑏 ∪ {𝑥}) ∖ 𝒫 𝑏) → ∃𝑐 ∈ 𝒫 𝑏𝑑 = (𝑐 ∪ {𝑥})) |
| 26 | 5, 4 | elrnmpti 5376 |
. . . . . . 7
⊢ (𝑑 ∈ ran 𝐹 ↔ ∃𝑐 ∈ 𝒫 𝑏𝑑 = (𝑐 ∪ {𝑥})) |
| 27 | 25, 26 | sylibr 224 |
. . . . . 6
⊢ (𝑑 ∈ (𝒫 (𝑏 ∪ {𝑥}) ∖ 𝒫 𝑏) → 𝑑 ∈ ran 𝐹) |
| 28 | 27 | ssriv 3607 |
. . . . 5
⊢
(𝒫 (𝑏 ∪
{𝑥}) ∖ 𝒫
𝑏) ⊆ ran 𝐹 |
| 29 | | ssdomg 8001 |
. . . . 5
⊢ (ran
𝐹 ∈ Fin →
((𝒫 (𝑏 ∪ {𝑥}) ∖ 𝒫 𝑏) ⊆ ran 𝐹 → (𝒫 (𝑏 ∪ {𝑥}) ∖ 𝒫 𝑏) ≼ ran 𝐹)) |
| 30 | 12, 28, 29 | mpisyl 21 |
. . . 4
⊢
(𝒫 𝑏 ∈
Fin → (𝒫 (𝑏
∪ {𝑥}) ∖
𝒫 𝑏) ≼ ran
𝐹) |
| 31 | | domfi 8181 |
. . . 4
⊢ ((ran
𝐹 ∈ Fin ∧
(𝒫 (𝑏 ∪ {𝑥}) ∖ 𝒫 𝑏) ≼ ran 𝐹) → (𝒫 (𝑏 ∪ {𝑥}) ∖ 𝒫 𝑏) ∈ Fin) |
| 32 | 12, 30, 31 | syl2anc 693 |
. . 3
⊢
(𝒫 𝑏 ∈
Fin → (𝒫 (𝑏
∪ {𝑥}) ∖
𝒫 𝑏) ∈
Fin) |
| 33 | | unfi 8227 |
. . 3
⊢
(((𝒫 (𝑏
∪ {𝑥}) ∖
𝒫 𝑏) ∈ Fin
∧ 𝒫 𝑏 ∈
Fin) → ((𝒫 (𝑏
∪ {𝑥}) ∖
𝒫 𝑏) ∪
𝒫 𝑏) ∈
Fin) |
| 34 | 32, 33 | mpancom 703 |
. 2
⊢
(𝒫 𝑏 ∈
Fin → ((𝒫 (𝑏
∪ {𝑥}) ∖
𝒫 𝑏) ∪
𝒫 𝑏) ∈
Fin) |
| 35 | 1, 34 | syl5eqel 2705 |
1
⊢
(𝒫 𝑏 ∈
Fin → 𝒫 (𝑏
∪ {𝑥}) ∈
Fin) |