Metamath Proof Explorer


Theorem suctrALTcf

Description: The sucessor of a transitive class is transitive. suctrALTcf , using conventional notation, was translated from virtual deduction form, suctrALTcfVD , using a translation program. (Contributed by Alan Sare, 13-Jun-2015) (Proof modification is discouraged.) (New usage is discouraged.)

Ref Expression
Assertion suctrALTcf ( Tr 𝐴 → Tr suc 𝐴 )

Proof

Step Hyp Ref Expression
1 sssucid 𝐴 ⊆ suc 𝐴
2 id ( Tr 𝐴 → Tr 𝐴 )
3 id ( ( 𝑧𝑦𝑦 ∈ suc 𝐴 ) → ( 𝑧𝑦𝑦 ∈ suc 𝐴 ) )
4 simpl ( ( 𝑧𝑦𝑦 ∈ suc 𝐴 ) → 𝑧𝑦 )
5 3 4 syl ( ( 𝑧𝑦𝑦 ∈ suc 𝐴 ) → 𝑧𝑦 )
6 id ( 𝑦𝐴𝑦𝐴 )
7 trel ( Tr 𝐴 → ( ( 𝑧𝑦𝑦𝐴 ) → 𝑧𝐴 ) )
8 7 3impib ( ( Tr 𝐴𝑧𝑦𝑦𝐴 ) → 𝑧𝐴 )
9 2 5 6 8 syl3an ( ( Tr 𝐴 ∧ ( 𝑧𝑦𝑦 ∈ suc 𝐴 ) ∧ 𝑦𝐴 ) → 𝑧𝐴 )
10 ssel2 ( ( 𝐴 ⊆ suc 𝐴𝑧𝐴 ) → 𝑧 ∈ suc 𝐴 )
11 1 9 10 eel0321old ( ( Tr 𝐴 ∧ ( 𝑧𝑦𝑦 ∈ suc 𝐴 ) ∧ 𝑦𝐴 ) → 𝑧 ∈ suc 𝐴 )
12 11 3expia ( ( Tr 𝐴 ∧ ( 𝑧𝑦𝑦 ∈ suc 𝐴 ) ) → ( 𝑦𝐴𝑧 ∈ suc 𝐴 ) )
13 id ( 𝑦 = 𝐴𝑦 = 𝐴 )
14 eleq2 ( 𝑦 = 𝐴 → ( 𝑧𝑦𝑧𝐴 ) )
15 14 biimpac ( ( 𝑧𝑦𝑦 = 𝐴 ) → 𝑧𝐴 )
16 5 13 15 syl2an ( ( ( 𝑧𝑦𝑦 ∈ suc 𝐴 ) ∧ 𝑦 = 𝐴 ) → 𝑧𝐴 )
17 1 16 10 eel021old ( ( ( 𝑧𝑦𝑦 ∈ suc 𝐴 ) ∧ 𝑦 = 𝐴 ) → 𝑧 ∈ suc 𝐴 )
18 17 ex ( ( 𝑧𝑦𝑦 ∈ suc 𝐴 ) → ( 𝑦 = 𝐴𝑧 ∈ suc 𝐴 ) )
19 simpr ( ( 𝑧𝑦𝑦 ∈ suc 𝐴 ) → 𝑦 ∈ suc 𝐴 )
20 3 19 syl ( ( 𝑧𝑦𝑦 ∈ suc 𝐴 ) → 𝑦 ∈ suc 𝐴 )
21 elsuci ( 𝑦 ∈ suc 𝐴 → ( 𝑦𝐴𝑦 = 𝐴 ) )
22 20 21 syl ( ( 𝑧𝑦𝑦 ∈ suc 𝐴 ) → ( 𝑦𝐴𝑦 = 𝐴 ) )
23 jao ( ( 𝑦𝐴𝑧 ∈ suc 𝐴 ) → ( ( 𝑦 = 𝐴𝑧 ∈ suc 𝐴 ) → ( ( 𝑦𝐴𝑦 = 𝐴 ) → 𝑧 ∈ suc 𝐴 ) ) )
24 23 3imp ( ( ( 𝑦𝐴𝑧 ∈ suc 𝐴 ) ∧ ( 𝑦 = 𝐴𝑧 ∈ suc 𝐴 ) ∧ ( 𝑦𝐴𝑦 = 𝐴 ) ) → 𝑧 ∈ suc 𝐴 )
25 12 18 22 24 eel2122old ( ( Tr 𝐴 ∧ ( 𝑧𝑦𝑦 ∈ suc 𝐴 ) ) → 𝑧 ∈ suc 𝐴 )
26 25 ex ( Tr 𝐴 → ( ( 𝑧𝑦𝑦 ∈ suc 𝐴 ) → 𝑧 ∈ suc 𝐴 ) )
27 26 alrimivv ( Tr 𝐴 → ∀ 𝑧𝑦 ( ( 𝑧𝑦𝑦 ∈ suc 𝐴 ) → 𝑧 ∈ suc 𝐴 ) )
28 dftr2 ( Tr suc 𝐴 ↔ ∀ 𝑧𝑦 ( ( 𝑧𝑦𝑦 ∈ suc 𝐴 ) → 𝑧 ∈ suc 𝐴 ) )
29 28 biimpri ( ∀ 𝑧𝑦 ( ( 𝑧𝑦𝑦 ∈ suc 𝐴 ) → 𝑧 ∈ suc 𝐴 ) → Tr suc 𝐴 )
30 27 29 syl ( Tr 𝐴 → Tr suc 𝐴 )
31 30 iin1 ( Tr 𝐴 → Tr suc 𝐴 )