| 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 ) |