| Step | Hyp | Ref | Expression | 
|---|
| 1 |  | simp2 1138 | . 2
⊢ ((𝐴 ∈ dom card ∧ 𝐴 ≠ ∅ ∧
∀𝑧((𝑧 ⊆ 𝐴 ∧ 𝑧 ≠ ∅ ∧ [⊊] Or
𝑧) → ∪ 𝑧
∈ 𝐴)) → 𝐴 ≠ ∅) | 
| 2 |  | simp1 1137 | . . . 4
⊢ ((𝐴 ∈ dom card ∧ 𝐴 ≠ ∅ ∧
∀𝑧((𝑧 ⊆ 𝐴 ∧ 𝑧 ≠ ∅ ∧ [⊊] Or
𝑧) → ∪ 𝑧
∈ 𝐴)) → 𝐴 ∈ dom
card) | 
| 3 |  | snfi 9083 | . . . . 5
⊢ {∅}
∈ Fin | 
| 4 |  | finnum 9988 | . . . . 5
⊢
({∅} ∈ Fin → {∅} ∈ dom card) | 
| 5 | 3, 4 | ax-mp 5 | . . . 4
⊢ {∅}
∈ dom card | 
| 6 |  | unnum 10237 | . . . 4
⊢ ((𝐴 ∈ dom card ∧ {∅}
∈ dom card) → (𝐴
∪ {∅}) ∈ dom card) | 
| 7 | 2, 5, 6 | sylancl 586 | . . 3
⊢ ((𝐴 ∈ dom card ∧ 𝐴 ≠ ∅ ∧
∀𝑧((𝑧 ⊆ 𝐴 ∧ 𝑧 ≠ ∅ ∧ [⊊] Or
𝑧) → ∪ 𝑧
∈ 𝐴)) → (𝐴 ∪ {∅}) ∈ dom
card) | 
| 8 |  | uncom 4158 | . . . . . . . . 9
⊢ (𝐴 ∪ {∅}) = ({∅}
∪ 𝐴) | 
| 9 | 8 | sseq2i 4013 | . . . . . . . 8
⊢ (𝑤 ⊆ (𝐴 ∪ {∅}) ↔ 𝑤 ⊆ ({∅} ∪ 𝐴)) | 
| 10 |  | ssundif 4488 | . . . . . . . 8
⊢ (𝑤 ⊆ ({∅} ∪ 𝐴) ↔ (𝑤 ∖ {∅}) ⊆ 𝐴) | 
| 11 | 9, 10 | bitri 275 | . . . . . . 7
⊢ (𝑤 ⊆ (𝐴 ∪ {∅}) ↔ (𝑤 ∖ {∅}) ⊆ 𝐴) | 
| 12 |  | difss 4136 | . . . . . . . . 9
⊢ (𝑤 ∖ {∅}) ⊆
𝑤 | 
| 13 |  | soss 5612 | . . . . . . . . 9
⊢ ((𝑤 ∖ {∅}) ⊆
𝑤 → (
[⊊] Or 𝑤
→ [⊊] Or (𝑤 ∖ {∅}))) | 
| 14 | 12, 13 | ax-mp 5 | . . . . . . . 8
⊢ (
[⊊] Or 𝑤
→ [⊊] Or (𝑤 ∖ {∅})) | 
| 15 |  | ssdif0 4366 | . . . . . . . . . . 11
⊢ (𝑤 ⊆ {∅} ↔ (𝑤 ∖ {∅}) =
∅) | 
| 16 |  | uni0b 4933 | . . . . . . . . . . . . 13
⊢ (∪ 𝑤 =
∅ ↔ 𝑤 ⊆
{∅}) | 
| 17 | 16 | biimpri 228 | . . . . . . . . . . . 12
⊢ (𝑤 ⊆ {∅} → ∪ 𝑤 =
∅) | 
| 18 | 17 | eleq1d 2826 | . . . . . . . . . . 11
⊢ (𝑤 ⊆ {∅} → (∪ 𝑤
∈ (𝐴 ∪ {∅})
↔ ∅ ∈ (𝐴
∪ {∅}))) | 
| 19 | 15, 18 | sylbir 235 | . . . . . . . . . 10
⊢ ((𝑤 ∖ {∅}) = ∅
→ (∪ 𝑤 ∈ (𝐴 ∪ {∅}) ↔ ∅ ∈
(𝐴 ∪
{∅}))) | 
| 20 | 19 | imbi2d 340 | . . . . . . . . 9
⊢ ((𝑤 ∖ {∅}) = ∅
→ ((∀𝑧((𝑧 ⊆ 𝐴 ∧ 𝑧 ≠ ∅ ∧ [⊊] Or
𝑧) → ∪ 𝑧
∈ 𝐴) → ∪ 𝑤
∈ (𝐴 ∪ {∅}))
↔ (∀𝑧((𝑧 ⊆ 𝐴 ∧ 𝑧 ≠ ∅ ∧ [⊊] Or
𝑧) → ∪ 𝑧
∈ 𝐴) → ∅
∈ (𝐴 ∪
{∅})))) | 
| 21 |  | vex 3484 | . . . . . . . . . . . . . . 15
⊢ 𝑤 ∈ V | 
| 22 | 21 | difexi 5330 | . . . . . . . . . . . . . 14
⊢ (𝑤 ∖ {∅}) ∈
V | 
| 23 |  | sseq1 4009 | . . . . . . . . . . . . . . . 16
⊢ (𝑧 = (𝑤 ∖ {∅}) → (𝑧 ⊆ 𝐴 ↔ (𝑤 ∖ {∅}) ⊆ 𝐴)) | 
| 24 |  | neeq1 3003 | . . . . . . . . . . . . . . . 16
⊢ (𝑧 = (𝑤 ∖ {∅}) → (𝑧 ≠ ∅ ↔ (𝑤 ∖ {∅}) ≠
∅)) | 
| 25 |  | soeq2 5614 | . . . . . . . . . . . . . . . 16
⊢ (𝑧 = (𝑤 ∖ {∅}) → (
[⊊] Or 𝑧
↔ [⊊] Or (𝑤 ∖ {∅}))) | 
| 26 | 23, 24, 25 | 3anbi123d 1438 | . . . . . . . . . . . . . . 15
⊢ (𝑧 = (𝑤 ∖ {∅}) → ((𝑧 ⊆ 𝐴 ∧ 𝑧 ≠ ∅ ∧ [⊊] Or
𝑧) ↔ ((𝑤 ∖ {∅}) ⊆
𝐴 ∧ (𝑤 ∖ {∅}) ≠ ∅ ∧
[⊊] Or (𝑤
∖ {∅})))) | 
| 27 |  | unieq 4918 | . . . . . . . . . . . . . . . 16
⊢ (𝑧 = (𝑤 ∖ {∅}) → ∪ 𝑧 =
∪ (𝑤 ∖ {∅})) | 
| 28 | 27 | eleq1d 2826 | . . . . . . . . . . . . . . 15
⊢ (𝑧 = (𝑤 ∖ {∅}) → (∪ 𝑧
∈ 𝐴 ↔ ∪ (𝑤
∖ {∅}) ∈ 𝐴)) | 
| 29 | 26, 28 | imbi12d 344 | . . . . . . . . . . . . . 14
⊢ (𝑧 = (𝑤 ∖ {∅}) → (((𝑧 ⊆ 𝐴 ∧ 𝑧 ≠ ∅ ∧ [⊊] Or
𝑧) → ∪ 𝑧
∈ 𝐴) ↔ (((𝑤 ∖ {∅}) ⊆
𝐴 ∧ (𝑤 ∖ {∅}) ≠ ∅ ∧
[⊊] Or (𝑤
∖ {∅})) → ∪ (𝑤 ∖ {∅}) ∈ 𝐴))) | 
| 30 | 22, 29 | spcv 3605 | . . . . . . . . . . . . 13
⊢
(∀𝑧((𝑧 ⊆ 𝐴 ∧ 𝑧 ≠ ∅ ∧ [⊊] Or
𝑧) → ∪ 𝑧
∈ 𝐴) → (((𝑤 ∖ {∅}) ⊆
𝐴 ∧ (𝑤 ∖ {∅}) ≠ ∅ ∧
[⊊] Or (𝑤
∖ {∅})) → ∪ (𝑤 ∖ {∅}) ∈ 𝐴)) | 
| 31 | 30 | com12 32 | . . . . . . . . . . . 12
⊢ (((𝑤 ∖ {∅}) ⊆
𝐴 ∧ (𝑤 ∖ {∅}) ≠ ∅ ∧
[⊊] Or (𝑤
∖ {∅})) → (∀𝑧((𝑧 ⊆ 𝐴 ∧ 𝑧 ≠ ∅ ∧ [⊊] Or
𝑧) → ∪ 𝑧
∈ 𝐴) → ∪ (𝑤
∖ {∅}) ∈ 𝐴)) | 
| 32 | 31 | 3expa 1119 | . . . . . . . . . . 11
⊢ ((((𝑤 ∖ {∅}) ⊆
𝐴 ∧ (𝑤 ∖ {∅}) ≠ ∅) ∧
[⊊] Or (𝑤
∖ {∅})) → (∀𝑧((𝑧 ⊆ 𝐴 ∧ 𝑧 ≠ ∅ ∧ [⊊] Or
𝑧) → ∪ 𝑧
∈ 𝐴) → ∪ (𝑤
∖ {∅}) ∈ 𝐴)) | 
| 33 | 32 | an32s 652 | . . . . . . . . . 10
⊢ ((((𝑤 ∖ {∅}) ⊆
𝐴 ∧ [⊊]
Or (𝑤 ∖ {∅}))
∧ (𝑤 ∖ {∅})
≠ ∅) → (∀𝑧((𝑧 ⊆ 𝐴 ∧ 𝑧 ≠ ∅ ∧ [⊊] Or
𝑧) → ∪ 𝑧
∈ 𝐴) → ∪ (𝑤
∖ {∅}) ∈ 𝐴)) | 
| 34 |  | unidif0 5360 | . . . . . . . . . . . 12
⊢ ∪ (𝑤
∖ {∅}) = ∪ 𝑤 | 
| 35 | 34 | eleq1i 2832 | . . . . . . . . . . 11
⊢ (∪ (𝑤
∖ {∅}) ∈ 𝐴
↔ ∪ 𝑤 ∈ 𝐴) | 
| 36 |  | elun1 4182 | . . . . . . . . . . 11
⊢ (∪ 𝑤
∈ 𝐴 → ∪ 𝑤
∈ (𝐴 ∪
{∅})) | 
| 37 | 35, 36 | sylbi 217 | . . . . . . . . . 10
⊢ (∪ (𝑤
∖ {∅}) ∈ 𝐴
→ ∪ 𝑤 ∈ (𝐴 ∪ {∅})) | 
| 38 | 33, 37 | syl6 35 | . . . . . . . . 9
⊢ ((((𝑤 ∖ {∅}) ⊆
𝐴 ∧ [⊊]
Or (𝑤 ∖ {∅}))
∧ (𝑤 ∖ {∅})
≠ ∅) → (∀𝑧((𝑧 ⊆ 𝐴 ∧ 𝑧 ≠ ∅ ∧ [⊊] Or
𝑧) → ∪ 𝑧
∈ 𝐴) → ∪ 𝑤
∈ (𝐴 ∪
{∅}))) | 
| 39 |  | 0ex 5307 | . . . . . . . . . . . 12
⊢ ∅
∈ V | 
| 40 | 39 | snid 4662 | . . . . . . . . . . 11
⊢ ∅
∈ {∅} | 
| 41 |  | elun2 4183 | . . . . . . . . . . 11
⊢ (∅
∈ {∅} → ∅ ∈ (𝐴 ∪ {∅})) | 
| 42 | 40, 41 | ax-mp 5 | . . . . . . . . . 10
⊢ ∅
∈ (𝐴 ∪
{∅}) | 
| 43 | 42 | 2a1i 12 | . . . . . . . . 9
⊢ (((𝑤 ∖ {∅}) ⊆
𝐴 ∧ [⊊]
Or (𝑤 ∖ {∅}))
→ (∀𝑧((𝑧 ⊆ 𝐴 ∧ 𝑧 ≠ ∅ ∧ [⊊] Or
𝑧) → ∪ 𝑧
∈ 𝐴) → ∅
∈ (𝐴 ∪
{∅}))) | 
| 44 | 20, 38, 43 | pm2.61ne 3027 | . . . . . . . 8
⊢ (((𝑤 ∖ {∅}) ⊆
𝐴 ∧ [⊊]
Or (𝑤 ∖ {∅}))
→ (∀𝑧((𝑧 ⊆ 𝐴 ∧ 𝑧 ≠ ∅ ∧ [⊊] Or
𝑧) → ∪ 𝑧
∈ 𝐴) → ∪ 𝑤
∈ (𝐴 ∪
{∅}))) | 
| 45 | 14, 44 | sylan2 593 | . . . . . . 7
⊢ (((𝑤 ∖ {∅}) ⊆
𝐴 ∧ [⊊]
Or 𝑤) → (∀𝑧((𝑧 ⊆ 𝐴 ∧ 𝑧 ≠ ∅ ∧ [⊊] Or
𝑧) → ∪ 𝑧
∈ 𝐴) → ∪ 𝑤
∈ (𝐴 ∪
{∅}))) | 
| 46 | 11, 45 | sylanb 581 | . . . . . 6
⊢ ((𝑤 ⊆ (𝐴 ∪ {∅}) ∧ [⊊] Or
𝑤) → (∀𝑧((𝑧 ⊆ 𝐴 ∧ 𝑧 ≠ ∅ ∧ [⊊] Or
𝑧) → ∪ 𝑧
∈ 𝐴) → ∪ 𝑤
∈ (𝐴 ∪
{∅}))) | 
| 47 | 46 | com12 32 | . . . . 5
⊢
(∀𝑧((𝑧 ⊆ 𝐴 ∧ 𝑧 ≠ ∅ ∧ [⊊] Or
𝑧) → ∪ 𝑧
∈ 𝐴) → ((𝑤 ⊆ (𝐴 ∪ {∅}) ∧ [⊊] Or
𝑤) → ∪ 𝑤
∈ (𝐴 ∪
{∅}))) | 
| 48 | 47 | alrimiv 1927 | . . . 4
⊢
(∀𝑧((𝑧 ⊆ 𝐴 ∧ 𝑧 ≠ ∅ ∧ [⊊] Or
𝑧) → ∪ 𝑧
∈ 𝐴) →
∀𝑤((𝑤 ⊆ (𝐴 ∪ {∅}) ∧ [⊊] Or
𝑤) → ∪ 𝑤
∈ (𝐴 ∪
{∅}))) | 
| 49 | 48 | 3ad2ant3 1136 | . . 3
⊢ ((𝐴 ∈ dom card ∧ 𝐴 ≠ ∅ ∧
∀𝑧((𝑧 ⊆ 𝐴 ∧ 𝑧 ≠ ∅ ∧ [⊊] Or
𝑧) → ∪ 𝑧
∈ 𝐴)) →
∀𝑤((𝑤 ⊆ (𝐴 ∪ {∅}) ∧ [⊊] Or
𝑤) → ∪ 𝑤
∈ (𝐴 ∪
{∅}))) | 
| 50 |  | zorng 10544 | . . 3
⊢ (((𝐴 ∪ {∅}) ∈ dom
card ∧ ∀𝑤((𝑤 ⊆ (𝐴 ∪ {∅}) ∧ [⊊] Or
𝑤) → ∪ 𝑤
∈ (𝐴 ∪
{∅}))) → ∃𝑥 ∈ (𝐴 ∪ {∅})∀𝑦 ∈ (𝐴 ∪ {∅}) ¬ 𝑥 ⊊ 𝑦) | 
| 51 | 7, 49, 50 | syl2anc 584 | . 2
⊢ ((𝐴 ∈ dom card ∧ 𝐴 ≠ ∅ ∧
∀𝑧((𝑧 ⊆ 𝐴 ∧ 𝑧 ≠ ∅ ∧ [⊊] Or
𝑧) → ∪ 𝑧
∈ 𝐴)) →
∃𝑥 ∈ (𝐴 ∪ {∅})∀𝑦 ∈ (𝐴 ∪ {∅}) ¬ 𝑥 ⊊ 𝑦) | 
| 52 |  | ssun1 4178 | . . . . 5
⊢ 𝐴 ⊆ (𝐴 ∪ {∅}) | 
| 53 |  | ssralv 4052 | . . . . 5
⊢ (𝐴 ⊆ (𝐴 ∪ {∅}) → (∀𝑦 ∈ (𝐴 ∪ {∅}) ¬ 𝑥 ⊊ 𝑦 → ∀𝑦 ∈ 𝐴 ¬ 𝑥 ⊊ 𝑦)) | 
| 54 | 52, 53 | ax-mp 5 | . . . 4
⊢
(∀𝑦 ∈
(𝐴 ∪ {∅}) ¬
𝑥 ⊊ 𝑦 → ∀𝑦 ∈ 𝐴 ¬ 𝑥 ⊊ 𝑦) | 
| 55 | 54 | reximi 3084 | . . 3
⊢
(∃𝑥 ∈
(𝐴 ∪
{∅})∀𝑦 ∈
(𝐴 ∪ {∅}) ¬
𝑥 ⊊ 𝑦 → ∃𝑥 ∈ (𝐴 ∪ {∅})∀𝑦 ∈ 𝐴 ¬ 𝑥 ⊊ 𝑦) | 
| 56 |  | rexun 4196 | . . . 4
⊢
(∃𝑥 ∈
(𝐴 ∪
{∅})∀𝑦 ∈
𝐴 ¬ 𝑥 ⊊ 𝑦 ↔ (∃𝑥 ∈ 𝐴 ∀𝑦 ∈ 𝐴 ¬ 𝑥 ⊊ 𝑦 ∨ ∃𝑥 ∈ {∅}∀𝑦 ∈ 𝐴 ¬ 𝑥 ⊊ 𝑦)) | 
| 57 |  | simpr 484 | . . . . 5
⊢ ((𝐴 ≠ ∅ ∧ ∃𝑥 ∈ 𝐴 ∀𝑦 ∈ 𝐴 ¬ 𝑥 ⊊ 𝑦) → ∃𝑥 ∈ 𝐴 ∀𝑦 ∈ 𝐴 ¬ 𝑥 ⊊ 𝑦) | 
| 58 |  | simpr 484 | . . . . . 6
⊢ ((𝐴 ≠ ∅ ∧ ∃𝑥 ∈ {∅}∀𝑦 ∈ 𝐴 ¬ 𝑥 ⊊ 𝑦) → ∃𝑥 ∈ {∅}∀𝑦 ∈ 𝐴 ¬ 𝑥 ⊊ 𝑦) | 
| 59 |  | psseq1 4090 | . . . . . . . . . . . 12
⊢ (𝑥 = ∅ → (𝑥 ⊊ 𝑦 ↔ ∅ ⊊ 𝑦)) | 
| 60 |  | 0pss 4447 | . . . . . . . . . . . 12
⊢ (∅
⊊ 𝑦 ↔ 𝑦 ≠ ∅) | 
| 61 | 59, 60 | bitrdi 287 | . . . . . . . . . . 11
⊢ (𝑥 = ∅ → (𝑥 ⊊ 𝑦 ↔ 𝑦 ≠ ∅)) | 
| 62 | 61 | notbid 318 | . . . . . . . . . 10
⊢ (𝑥 = ∅ → (¬ 𝑥 ⊊ 𝑦 ↔ ¬ 𝑦 ≠ ∅)) | 
| 63 |  | nne 2944 | . . . . . . . . . 10
⊢ (¬
𝑦 ≠ ∅ ↔ 𝑦 = ∅) | 
| 64 | 62, 63 | bitrdi 287 | . . . . . . . . 9
⊢ (𝑥 = ∅ → (¬ 𝑥 ⊊ 𝑦 ↔ 𝑦 = ∅)) | 
| 65 | 64 | ralbidv 3178 | . . . . . . . 8
⊢ (𝑥 = ∅ → (∀𝑦 ∈ 𝐴 ¬ 𝑥 ⊊ 𝑦 ↔ ∀𝑦 ∈ 𝐴 𝑦 = ∅)) | 
| 66 | 39, 65 | rexsn 4682 | . . . . . . 7
⊢
(∃𝑥 ∈
{∅}∀𝑦 ∈
𝐴 ¬ 𝑥 ⊊ 𝑦 ↔ ∀𝑦 ∈ 𝐴 𝑦 = ∅) | 
| 67 |  | eqsn 4829 | . . . . . . . 8
⊢ (𝐴 ≠ ∅ → (𝐴 = {∅} ↔
∀𝑦 ∈ 𝐴 𝑦 = ∅)) | 
| 68 | 67 | biimpar 477 | . . . . . . 7
⊢ ((𝐴 ≠ ∅ ∧
∀𝑦 ∈ 𝐴 𝑦 = ∅) → 𝐴 = {∅}) | 
| 69 | 66, 68 | sylan2b 594 | . . . . . 6
⊢ ((𝐴 ≠ ∅ ∧ ∃𝑥 ∈ {∅}∀𝑦 ∈ 𝐴 ¬ 𝑥 ⊊ 𝑦) → 𝐴 = {∅}) | 
| 70 | 58, 69 | rexeqtrrdv 3331 | . . . . 5
⊢ ((𝐴 ≠ ∅ ∧ ∃𝑥 ∈ {∅}∀𝑦 ∈ 𝐴 ¬ 𝑥 ⊊ 𝑦) → ∃𝑥 ∈ 𝐴 ∀𝑦 ∈ 𝐴 ¬ 𝑥 ⊊ 𝑦) | 
| 71 | 57, 70 | jaodan 960 | . . . 4
⊢ ((𝐴 ≠ ∅ ∧
(∃𝑥 ∈ 𝐴 ∀𝑦 ∈ 𝐴 ¬ 𝑥 ⊊ 𝑦 ∨ ∃𝑥 ∈ {∅}∀𝑦 ∈ 𝐴 ¬ 𝑥 ⊊ 𝑦)) → ∃𝑥 ∈ 𝐴 ∀𝑦 ∈ 𝐴 ¬ 𝑥 ⊊ 𝑦) | 
| 72 | 56, 71 | sylan2b 594 | . . 3
⊢ ((𝐴 ≠ ∅ ∧ ∃𝑥 ∈ (𝐴 ∪ {∅})∀𝑦 ∈ 𝐴 ¬ 𝑥 ⊊ 𝑦) → ∃𝑥 ∈ 𝐴 ∀𝑦 ∈ 𝐴 ¬ 𝑥 ⊊ 𝑦) | 
| 73 | 55, 72 | sylan2 593 | . 2
⊢ ((𝐴 ≠ ∅ ∧ ∃𝑥 ∈ (𝐴 ∪ {∅})∀𝑦 ∈ (𝐴 ∪ {∅}) ¬ 𝑥 ⊊ 𝑦) → ∃𝑥 ∈ 𝐴 ∀𝑦 ∈ 𝐴 ¬ 𝑥 ⊊ 𝑦) | 
| 74 | 1, 51, 73 | syl2anc 584 | 1
⊢ ((𝐴 ∈ dom card ∧ 𝐴 ≠ ∅ ∧
∀𝑧((𝑧 ⊆ 𝐴 ∧ 𝑧 ≠ ∅ ∧ [⊊] Or
𝑧) → ∪ 𝑧
∈ 𝐴)) →
∃𝑥 ∈ 𝐴 ∀𝑦 ∈ 𝐴 ¬ 𝑥 ⊊ 𝑦) |