Step |
Hyp |
Ref |
Expression |
1 |
|
sssucid |
⊢ 𝐴 ⊆ suc 𝐴 |
2 |
|
trel |
⊢ ( Tr 𝐴 → ( ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐴 ) → 𝑧 ∈ 𝐴 ) ) |
3 |
2
|
expd |
⊢ ( Tr 𝐴 → ( 𝑧 ∈ 𝑦 → ( 𝑦 ∈ 𝐴 → 𝑧 ∈ 𝐴 ) ) ) |
4 |
3
|
adantrd |
⊢ ( Tr 𝐴 → ( ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ suc 𝐴 ) → ( 𝑦 ∈ 𝐴 → 𝑧 ∈ 𝐴 ) ) ) |
5 |
|
ssel |
⊢ ( 𝐴 ⊆ suc 𝐴 → ( 𝑧 ∈ 𝐴 → 𝑧 ∈ suc 𝐴 ) ) |
6 |
1 4 5
|
ee03 |
⊢ ( Tr 𝐴 → ( ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ suc 𝐴 ) → ( 𝑦 ∈ 𝐴 → 𝑧 ∈ suc 𝐴 ) ) ) |
7 |
|
simpl |
⊢ ( ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ suc 𝐴 ) → 𝑧 ∈ 𝑦 ) |
8 |
7
|
a1i |
⊢ ( Tr 𝐴 → ( ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ suc 𝐴 ) → 𝑧 ∈ 𝑦 ) ) |
9 |
|
eleq2 |
⊢ ( 𝑦 = 𝐴 → ( 𝑧 ∈ 𝑦 ↔ 𝑧 ∈ 𝐴 ) ) |
10 |
9
|
biimpcd |
⊢ ( 𝑧 ∈ 𝑦 → ( 𝑦 = 𝐴 → 𝑧 ∈ 𝐴 ) ) |
11 |
8 10
|
syl6 |
⊢ ( Tr 𝐴 → ( ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ suc 𝐴 ) → ( 𝑦 = 𝐴 → 𝑧 ∈ 𝐴 ) ) ) |
12 |
1 11 5
|
ee03 |
⊢ ( Tr 𝐴 → ( ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ suc 𝐴 ) → ( 𝑦 = 𝐴 → 𝑧 ∈ suc 𝐴 ) ) ) |
13 |
|
simpr |
⊢ ( ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ suc 𝐴 ) → 𝑦 ∈ suc 𝐴 ) |
14 |
13
|
a1i |
⊢ ( Tr 𝐴 → ( ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ suc 𝐴 ) → 𝑦 ∈ suc 𝐴 ) ) |
15 |
|
elsuci |
⊢ ( 𝑦 ∈ suc 𝐴 → ( 𝑦 ∈ 𝐴 ∨ 𝑦 = 𝐴 ) ) |
16 |
14 15
|
syl6 |
⊢ ( Tr 𝐴 → ( ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ suc 𝐴 ) → ( 𝑦 ∈ 𝐴 ∨ 𝑦 = 𝐴 ) ) ) |
17 |
|
jao |
⊢ ( ( 𝑦 ∈ 𝐴 → 𝑧 ∈ suc 𝐴 ) → ( ( 𝑦 = 𝐴 → 𝑧 ∈ suc 𝐴 ) → ( ( 𝑦 ∈ 𝐴 ∨ 𝑦 = 𝐴 ) → 𝑧 ∈ suc 𝐴 ) ) ) |
18 |
6 12 16 17
|
ee222 |
⊢ ( Tr 𝐴 → ( ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ suc 𝐴 ) → 𝑧 ∈ suc 𝐴 ) ) |
19 |
18
|
alrimivv |
⊢ ( Tr 𝐴 → ∀ 𝑧 ∀ 𝑦 ( ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ suc 𝐴 ) → 𝑧 ∈ suc 𝐴 ) ) |
20 |
|
dftr2 |
⊢ ( Tr suc 𝐴 ↔ ∀ 𝑧 ∀ 𝑦 ( ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ suc 𝐴 ) → 𝑧 ∈ suc 𝐴 ) ) |
21 |
19 20
|
sylibr |
⊢ ( Tr 𝐴 → Tr suc 𝐴 ) |