| Step |
Hyp |
Ref |
Expression |
| 1 |
|
difss |
⊢ ( ∪ 𝐴 ∖ 𝐵 ) ⊆ ∪ 𝐴 |
| 2 |
|
ssnum |
⊢ ( ( ∪ 𝐴 ∈ dom card ∧ ( ∪ 𝐴 ∖ 𝐵 ) ⊆ ∪ 𝐴 ) → ( ∪ 𝐴 ∖ 𝐵 ) ∈ dom card ) |
| 3 |
1 2
|
mpan2 |
⊢ ( ∪ 𝐴 ∈ dom card → ( ∪ 𝐴 ∖ 𝐵 ) ∈ dom card ) |
| 4 |
|
isnum3 |
⊢ ( ( ∪ 𝐴 ∖ 𝐵 ) ∈ dom card ↔ ( card ‘ ( ∪ 𝐴 ∖ 𝐵 ) ) ≈ ( ∪ 𝐴 ∖ 𝐵 ) ) |
| 5 |
|
bren |
⊢ ( ( card ‘ ( ∪ 𝐴 ∖ 𝐵 ) ) ≈ ( ∪ 𝐴 ∖ 𝐵 ) ↔ ∃ 𝑓 𝑓 : ( card ‘ ( ∪ 𝐴 ∖ 𝐵 ) ) –1-1-onto→ ( ∪ 𝐴 ∖ 𝐵 ) ) |
| 6 |
4 5
|
bitri |
⊢ ( ( ∪ 𝐴 ∖ 𝐵 ) ∈ dom card ↔ ∃ 𝑓 𝑓 : ( card ‘ ( ∪ 𝐴 ∖ 𝐵 ) ) –1-1-onto→ ( ∪ 𝐴 ∖ 𝐵 ) ) |
| 7 |
|
simp1 |
⊢ ( ( 𝑓 : ( card ‘ ( ∪ 𝐴 ∖ 𝐵 ) ) –1-1-onto→ ( ∪ 𝐴 ∖ 𝐵 ) ∧ 𝐵 ∈ 𝐴 ∧ ∀ 𝑥 ( 𝑥 ∈ 𝐴 ↔ ( 𝒫 𝑥 ∩ Fin ) ⊆ 𝐴 ) ) → 𝑓 : ( card ‘ ( ∪ 𝐴 ∖ 𝐵 ) ) –1-1-onto→ ( ∪ 𝐴 ∖ 𝐵 ) ) |
| 8 |
|
simp2 |
⊢ ( ( 𝑓 : ( card ‘ ( ∪ 𝐴 ∖ 𝐵 ) ) –1-1-onto→ ( ∪ 𝐴 ∖ 𝐵 ) ∧ 𝐵 ∈ 𝐴 ∧ ∀ 𝑥 ( 𝑥 ∈ 𝐴 ↔ ( 𝒫 𝑥 ∩ Fin ) ⊆ 𝐴 ) ) → 𝐵 ∈ 𝐴 ) |
| 9 |
|
simp3 |
⊢ ( ( 𝑓 : ( card ‘ ( ∪ 𝐴 ∖ 𝐵 ) ) –1-1-onto→ ( ∪ 𝐴 ∖ 𝐵 ) ∧ 𝐵 ∈ 𝐴 ∧ ∀ 𝑥 ( 𝑥 ∈ 𝐴 ↔ ( 𝒫 𝑥 ∩ Fin ) ⊆ 𝐴 ) ) → ∀ 𝑥 ( 𝑥 ∈ 𝐴 ↔ ( 𝒫 𝑥 ∩ Fin ) ⊆ 𝐴 ) ) |
| 10 |
|
dmeq |
⊢ ( 𝑤 = 𝑧 → dom 𝑤 = dom 𝑧 ) |
| 11 |
10
|
unieqd |
⊢ ( 𝑤 = 𝑧 → ∪ dom 𝑤 = ∪ dom 𝑧 ) |
| 12 |
10 11
|
eqeq12d |
⊢ ( 𝑤 = 𝑧 → ( dom 𝑤 = ∪ dom 𝑤 ↔ dom 𝑧 = ∪ dom 𝑧 ) ) |
| 13 |
10
|
eqeq1d |
⊢ ( 𝑤 = 𝑧 → ( dom 𝑤 = ∅ ↔ dom 𝑧 = ∅ ) ) |
| 14 |
|
rneq |
⊢ ( 𝑤 = 𝑧 → ran 𝑤 = ran 𝑧 ) |
| 15 |
14
|
unieqd |
⊢ ( 𝑤 = 𝑧 → ∪ ran 𝑤 = ∪ ran 𝑧 ) |
| 16 |
13 15
|
ifbieq2d |
⊢ ( 𝑤 = 𝑧 → if ( dom 𝑤 = ∅ , 𝐵 , ∪ ran 𝑤 ) = if ( dom 𝑧 = ∅ , 𝐵 , ∪ ran 𝑧 ) ) |
| 17 |
|
id |
⊢ ( 𝑤 = 𝑧 → 𝑤 = 𝑧 ) |
| 18 |
17 11
|
fveq12d |
⊢ ( 𝑤 = 𝑧 → ( 𝑤 ‘ ∪ dom 𝑤 ) = ( 𝑧 ‘ ∪ dom 𝑧 ) ) |
| 19 |
11
|
fveq2d |
⊢ ( 𝑤 = 𝑧 → ( 𝑓 ‘ ∪ dom 𝑤 ) = ( 𝑓 ‘ ∪ dom 𝑧 ) ) |
| 20 |
19
|
sneqd |
⊢ ( 𝑤 = 𝑧 → { ( 𝑓 ‘ ∪ dom 𝑤 ) } = { ( 𝑓 ‘ ∪ dom 𝑧 ) } ) |
| 21 |
18 20
|
uneq12d |
⊢ ( 𝑤 = 𝑧 → ( ( 𝑤 ‘ ∪ dom 𝑤 ) ∪ { ( 𝑓 ‘ ∪ dom 𝑤 ) } ) = ( ( 𝑧 ‘ ∪ dom 𝑧 ) ∪ { ( 𝑓 ‘ ∪ dom 𝑧 ) } ) ) |
| 22 |
21
|
eleq1d |
⊢ ( 𝑤 = 𝑧 → ( ( ( 𝑤 ‘ ∪ dom 𝑤 ) ∪ { ( 𝑓 ‘ ∪ dom 𝑤 ) } ) ∈ 𝐴 ↔ ( ( 𝑧 ‘ ∪ dom 𝑧 ) ∪ { ( 𝑓 ‘ ∪ dom 𝑧 ) } ) ∈ 𝐴 ) ) |
| 23 |
22 20
|
ifbieq1d |
⊢ ( 𝑤 = 𝑧 → if ( ( ( 𝑤 ‘ ∪ dom 𝑤 ) ∪ { ( 𝑓 ‘ ∪ dom 𝑤 ) } ) ∈ 𝐴 , { ( 𝑓 ‘ ∪ dom 𝑤 ) } , ∅ ) = if ( ( ( 𝑧 ‘ ∪ dom 𝑧 ) ∪ { ( 𝑓 ‘ ∪ dom 𝑧 ) } ) ∈ 𝐴 , { ( 𝑓 ‘ ∪ dom 𝑧 ) } , ∅ ) ) |
| 24 |
18 23
|
uneq12d |
⊢ ( 𝑤 = 𝑧 → ( ( 𝑤 ‘ ∪ dom 𝑤 ) ∪ if ( ( ( 𝑤 ‘ ∪ dom 𝑤 ) ∪ { ( 𝑓 ‘ ∪ dom 𝑤 ) } ) ∈ 𝐴 , { ( 𝑓 ‘ ∪ dom 𝑤 ) } , ∅ ) ) = ( ( 𝑧 ‘ ∪ dom 𝑧 ) ∪ if ( ( ( 𝑧 ‘ ∪ dom 𝑧 ) ∪ { ( 𝑓 ‘ ∪ dom 𝑧 ) } ) ∈ 𝐴 , { ( 𝑓 ‘ ∪ dom 𝑧 ) } , ∅ ) ) ) |
| 25 |
12 16 24
|
ifbieq12d |
⊢ ( 𝑤 = 𝑧 → if ( dom 𝑤 = ∪ dom 𝑤 , if ( dom 𝑤 = ∅ , 𝐵 , ∪ ran 𝑤 ) , ( ( 𝑤 ‘ ∪ dom 𝑤 ) ∪ if ( ( ( 𝑤 ‘ ∪ dom 𝑤 ) ∪ { ( 𝑓 ‘ ∪ dom 𝑤 ) } ) ∈ 𝐴 , { ( 𝑓 ‘ ∪ dom 𝑤 ) } , ∅ ) ) ) = if ( dom 𝑧 = ∪ dom 𝑧 , if ( dom 𝑧 = ∅ , 𝐵 , ∪ ran 𝑧 ) , ( ( 𝑧 ‘ ∪ dom 𝑧 ) ∪ if ( ( ( 𝑧 ‘ ∪ dom 𝑧 ) ∪ { ( 𝑓 ‘ ∪ dom 𝑧 ) } ) ∈ 𝐴 , { ( 𝑓 ‘ ∪ dom 𝑧 ) } , ∅ ) ) ) ) |
| 26 |
25
|
cbvmptv |
⊢ ( 𝑤 ∈ V ↦ if ( dom 𝑤 = ∪ dom 𝑤 , if ( dom 𝑤 = ∅ , 𝐵 , ∪ ran 𝑤 ) , ( ( 𝑤 ‘ ∪ dom 𝑤 ) ∪ if ( ( ( 𝑤 ‘ ∪ dom 𝑤 ) ∪ { ( 𝑓 ‘ ∪ dom 𝑤 ) } ) ∈ 𝐴 , { ( 𝑓 ‘ ∪ dom 𝑤 ) } , ∅ ) ) ) ) = ( 𝑧 ∈ V ↦ if ( dom 𝑧 = ∪ dom 𝑧 , if ( dom 𝑧 = ∅ , 𝐵 , ∪ ran 𝑧 ) , ( ( 𝑧 ‘ ∪ dom 𝑧 ) ∪ if ( ( ( 𝑧 ‘ ∪ dom 𝑧 ) ∪ { ( 𝑓 ‘ ∪ dom 𝑧 ) } ) ∈ 𝐴 , { ( 𝑓 ‘ ∪ dom 𝑧 ) } , ∅ ) ) ) ) |
| 27 |
|
recseq |
⊢ ( ( 𝑤 ∈ V ↦ if ( dom 𝑤 = ∪ dom 𝑤 , if ( dom 𝑤 = ∅ , 𝐵 , ∪ ran 𝑤 ) , ( ( 𝑤 ‘ ∪ dom 𝑤 ) ∪ if ( ( ( 𝑤 ‘ ∪ dom 𝑤 ) ∪ { ( 𝑓 ‘ ∪ dom 𝑤 ) } ) ∈ 𝐴 , { ( 𝑓 ‘ ∪ dom 𝑤 ) } , ∅ ) ) ) ) = ( 𝑧 ∈ V ↦ if ( dom 𝑧 = ∪ dom 𝑧 , if ( dom 𝑧 = ∅ , 𝐵 , ∪ ran 𝑧 ) , ( ( 𝑧 ‘ ∪ dom 𝑧 ) ∪ if ( ( ( 𝑧 ‘ ∪ dom 𝑧 ) ∪ { ( 𝑓 ‘ ∪ dom 𝑧 ) } ) ∈ 𝐴 , { ( 𝑓 ‘ ∪ dom 𝑧 ) } , ∅ ) ) ) ) → recs ( ( 𝑤 ∈ V ↦ if ( dom 𝑤 = ∪ dom 𝑤 , if ( dom 𝑤 = ∅ , 𝐵 , ∪ ran 𝑤 ) , ( ( 𝑤 ‘ ∪ dom 𝑤 ) ∪ if ( ( ( 𝑤 ‘ ∪ dom 𝑤 ) ∪ { ( 𝑓 ‘ ∪ dom 𝑤 ) } ) ∈ 𝐴 , { ( 𝑓 ‘ ∪ dom 𝑤 ) } , ∅ ) ) ) ) ) = recs ( ( 𝑧 ∈ V ↦ if ( dom 𝑧 = ∪ dom 𝑧 , if ( dom 𝑧 = ∅ , 𝐵 , ∪ ran 𝑧 ) , ( ( 𝑧 ‘ ∪ dom 𝑧 ) ∪ if ( ( ( 𝑧 ‘ ∪ dom 𝑧 ) ∪ { ( 𝑓 ‘ ∪ dom 𝑧 ) } ) ∈ 𝐴 , { ( 𝑓 ‘ ∪ dom 𝑧 ) } , ∅ ) ) ) ) ) ) |
| 28 |
26 27
|
ax-mp |
⊢ recs ( ( 𝑤 ∈ V ↦ if ( dom 𝑤 = ∪ dom 𝑤 , if ( dom 𝑤 = ∅ , 𝐵 , ∪ ran 𝑤 ) , ( ( 𝑤 ‘ ∪ dom 𝑤 ) ∪ if ( ( ( 𝑤 ‘ ∪ dom 𝑤 ) ∪ { ( 𝑓 ‘ ∪ dom 𝑤 ) } ) ∈ 𝐴 , { ( 𝑓 ‘ ∪ dom 𝑤 ) } , ∅ ) ) ) ) ) = recs ( ( 𝑧 ∈ V ↦ if ( dom 𝑧 = ∪ dom 𝑧 , if ( dom 𝑧 = ∅ , 𝐵 , ∪ ran 𝑧 ) , ( ( 𝑧 ‘ ∪ dom 𝑧 ) ∪ if ( ( ( 𝑧 ‘ ∪ dom 𝑧 ) ∪ { ( 𝑓 ‘ ∪ dom 𝑧 ) } ) ∈ 𝐴 , { ( 𝑓 ‘ ∪ dom 𝑧 ) } , ∅ ) ) ) ) ) |
| 29 |
7 8 9 28
|
ttukeylem7 |
⊢ ( ( 𝑓 : ( card ‘ ( ∪ 𝐴 ∖ 𝐵 ) ) –1-1-onto→ ( ∪ 𝐴 ∖ 𝐵 ) ∧ 𝐵 ∈ 𝐴 ∧ ∀ 𝑥 ( 𝑥 ∈ 𝐴 ↔ ( 𝒫 𝑥 ∩ Fin ) ⊆ 𝐴 ) ) → ∃ 𝑥 ∈ 𝐴 ( 𝐵 ⊆ 𝑥 ∧ ∀ 𝑦 ∈ 𝐴 ¬ 𝑥 ⊊ 𝑦 ) ) |
| 30 |
29
|
3expib |
⊢ ( 𝑓 : ( card ‘ ( ∪ 𝐴 ∖ 𝐵 ) ) –1-1-onto→ ( ∪ 𝐴 ∖ 𝐵 ) → ( ( 𝐵 ∈ 𝐴 ∧ ∀ 𝑥 ( 𝑥 ∈ 𝐴 ↔ ( 𝒫 𝑥 ∩ Fin ) ⊆ 𝐴 ) ) → ∃ 𝑥 ∈ 𝐴 ( 𝐵 ⊆ 𝑥 ∧ ∀ 𝑦 ∈ 𝐴 ¬ 𝑥 ⊊ 𝑦 ) ) ) |
| 31 |
30
|
exlimiv |
⊢ ( ∃ 𝑓 𝑓 : ( card ‘ ( ∪ 𝐴 ∖ 𝐵 ) ) –1-1-onto→ ( ∪ 𝐴 ∖ 𝐵 ) → ( ( 𝐵 ∈ 𝐴 ∧ ∀ 𝑥 ( 𝑥 ∈ 𝐴 ↔ ( 𝒫 𝑥 ∩ Fin ) ⊆ 𝐴 ) ) → ∃ 𝑥 ∈ 𝐴 ( 𝐵 ⊆ 𝑥 ∧ ∀ 𝑦 ∈ 𝐴 ¬ 𝑥 ⊊ 𝑦 ) ) ) |
| 32 |
6 31
|
sylbi |
⊢ ( ( ∪ 𝐴 ∖ 𝐵 ) ∈ dom card → ( ( 𝐵 ∈ 𝐴 ∧ ∀ 𝑥 ( 𝑥 ∈ 𝐴 ↔ ( 𝒫 𝑥 ∩ Fin ) ⊆ 𝐴 ) ) → ∃ 𝑥 ∈ 𝐴 ( 𝐵 ⊆ 𝑥 ∧ ∀ 𝑦 ∈ 𝐴 ¬ 𝑥 ⊊ 𝑦 ) ) ) |
| 33 |
3 32
|
syl |
⊢ ( ∪ 𝐴 ∈ dom card → ( ( 𝐵 ∈ 𝐴 ∧ ∀ 𝑥 ( 𝑥 ∈ 𝐴 ↔ ( 𝒫 𝑥 ∩ Fin ) ⊆ 𝐴 ) ) → ∃ 𝑥 ∈ 𝐴 ( 𝐵 ⊆ 𝑥 ∧ ∀ 𝑦 ∈ 𝐴 ¬ 𝑥 ⊊ 𝑦 ) ) ) |
| 34 |
33
|
3impib |
⊢ ( ( ∪ 𝐴 ∈ dom card ∧ 𝐵 ∈ 𝐴 ∧ ∀ 𝑥 ( 𝑥 ∈ 𝐴 ↔ ( 𝒫 𝑥 ∩ Fin ) ⊆ 𝐴 ) ) → ∃ 𝑥 ∈ 𝐴 ( 𝐵 ⊆ 𝑥 ∧ ∀ 𝑦 ∈ 𝐴 ¬ 𝑥 ⊊ 𝑦 ) ) |