Step |
Hyp |
Ref |
Expression |
1 |
|
fveq2 |
⊢ ( 𝐴 = ∅ → ( rank ‘ 𝐴 ) = ( rank ‘ ∅ ) ) |
2 |
|
r1funlim |
⊢ ( Fun 𝑅1 ∧ Lim dom 𝑅1 ) |
3 |
2
|
simpri |
⊢ Lim dom 𝑅1 |
4 |
|
limomss |
⊢ ( Lim dom 𝑅1 → ω ⊆ dom 𝑅1 ) |
5 |
3 4
|
ax-mp |
⊢ ω ⊆ dom 𝑅1 |
6 |
|
peano1 |
⊢ ∅ ∈ ω |
7 |
5 6
|
sselii |
⊢ ∅ ∈ dom 𝑅1 |
8 |
|
rankonid |
⊢ ( ∅ ∈ dom 𝑅1 ↔ ( rank ‘ ∅ ) = ∅ ) |
9 |
7 8
|
mpbi |
⊢ ( rank ‘ ∅ ) = ∅ |
10 |
1 9
|
eqtrdi |
⊢ ( 𝐴 = ∅ → ( rank ‘ 𝐴 ) = ∅ ) |
11 |
|
eqimss |
⊢ ( ( rank ‘ 𝐴 ) = ∅ → ( rank ‘ 𝐴 ) ⊆ ∅ ) |
12 |
11
|
adantl |
⊢ ( ( 𝐴 ∈ ∪ ( 𝑅1 “ On ) ∧ ( rank ‘ 𝐴 ) = ∅ ) → ( rank ‘ 𝐴 ) ⊆ ∅ ) |
13 |
|
simpl |
⊢ ( ( 𝐴 ∈ ∪ ( 𝑅1 “ On ) ∧ ( rank ‘ 𝐴 ) = ∅ ) → 𝐴 ∈ ∪ ( 𝑅1 “ On ) ) |
14 |
|
rankr1bg |
⊢ ( ( 𝐴 ∈ ∪ ( 𝑅1 “ On ) ∧ ∅ ∈ dom 𝑅1 ) → ( 𝐴 ⊆ ( 𝑅1 ‘ ∅ ) ↔ ( rank ‘ 𝐴 ) ⊆ ∅ ) ) |
15 |
13 7 14
|
sylancl |
⊢ ( ( 𝐴 ∈ ∪ ( 𝑅1 “ On ) ∧ ( rank ‘ 𝐴 ) = ∅ ) → ( 𝐴 ⊆ ( 𝑅1 ‘ ∅ ) ↔ ( rank ‘ 𝐴 ) ⊆ ∅ ) ) |
16 |
12 15
|
mpbird |
⊢ ( ( 𝐴 ∈ ∪ ( 𝑅1 “ On ) ∧ ( rank ‘ 𝐴 ) = ∅ ) → 𝐴 ⊆ ( 𝑅1 ‘ ∅ ) ) |
17 |
|
r10 |
⊢ ( 𝑅1 ‘ ∅ ) = ∅ |
18 |
16 17
|
sseqtrdi |
⊢ ( ( 𝐴 ∈ ∪ ( 𝑅1 “ On ) ∧ ( rank ‘ 𝐴 ) = ∅ ) → 𝐴 ⊆ ∅ ) |
19 |
|
ss0 |
⊢ ( 𝐴 ⊆ ∅ → 𝐴 = ∅ ) |
20 |
18 19
|
syl |
⊢ ( ( 𝐴 ∈ ∪ ( 𝑅1 “ On ) ∧ ( rank ‘ 𝐴 ) = ∅ ) → 𝐴 = ∅ ) |
21 |
20
|
ex |
⊢ ( 𝐴 ∈ ∪ ( 𝑅1 “ On ) → ( ( rank ‘ 𝐴 ) = ∅ → 𝐴 = ∅ ) ) |
22 |
10 21
|
impbid2 |
⊢ ( 𝐴 ∈ ∪ ( 𝑅1 “ On ) → ( 𝐴 = ∅ ↔ ( rank ‘ 𝐴 ) = ∅ ) ) |