Metamath Proof Explorer


Theorem nolt02o

Description: Given A less than B , equal to B up to X , and undefined at X , then B ( X ) = 2o . (Contributed by Scott Fenton, 6-Dec-2021)

Ref Expression
Assertion nolt02o ( ( ( 𝐴 No 𝐵 No 𝑋 ∈ On ) ∧ ( ( 𝐴𝑋 ) = ( 𝐵𝑋 ) ∧ 𝐴 <s 𝐵 ) ∧ ( 𝐴𝑋 ) = ∅ ) → ( 𝐵𝑋 ) = 2o )

Proof

Step Hyp Ref Expression
1 simp11 ( ( ( 𝐴 No 𝐵 No 𝑋 ∈ On ) ∧ ( ( 𝐴𝑋 ) = ( 𝐵𝑋 ) ∧ 𝐴 <s 𝐵 ) ∧ ( 𝐴𝑋 ) = ∅ ) → 𝐴 No )
2 sltso <s Or No
3 sonr ( ( <s Or No 𝐴 No ) → ¬ 𝐴 <s 𝐴 )
4 2 3 mpan ( 𝐴 No → ¬ 𝐴 <s 𝐴 )
5 1 4 syl ( ( ( 𝐴 No 𝐵 No 𝑋 ∈ On ) ∧ ( ( 𝐴𝑋 ) = ( 𝐵𝑋 ) ∧ 𝐴 <s 𝐵 ) ∧ ( 𝐴𝑋 ) = ∅ ) → ¬ 𝐴 <s 𝐴 )
6 simp2r ( ( ( 𝐴 No 𝐵 No 𝑋 ∈ On ) ∧ ( ( 𝐴𝑋 ) = ( 𝐵𝑋 ) ∧ 𝐴 <s 𝐵 ) ∧ ( 𝐴𝑋 ) = ∅ ) → 𝐴 <s 𝐵 )
7 breq2 ( 𝐴 = 𝐵 → ( 𝐴 <s 𝐴𝐴 <s 𝐵 ) )
8 6 7 syl5ibrcom ( ( ( 𝐴 No 𝐵 No 𝑋 ∈ On ) ∧ ( ( 𝐴𝑋 ) = ( 𝐵𝑋 ) ∧ 𝐴 <s 𝐵 ) ∧ ( 𝐴𝑋 ) = ∅ ) → ( 𝐴 = 𝐵𝐴 <s 𝐴 ) )
9 5 8 mtod ( ( ( 𝐴 No 𝐵 No 𝑋 ∈ On ) ∧ ( ( 𝐴𝑋 ) = ( 𝐵𝑋 ) ∧ 𝐴 <s 𝐵 ) ∧ ( 𝐴𝑋 ) = ∅ ) → ¬ 𝐴 = 𝐵 )
10 simpl2l ( ( ( ( 𝐴 No 𝐵 No 𝑋 ∈ On ) ∧ ( ( 𝐴𝑋 ) = ( 𝐵𝑋 ) ∧ 𝐴 <s 𝐵 ) ∧ ( 𝐴𝑋 ) = ∅ ) ∧ ( 𝐵𝑋 ) = ∅ ) → ( 𝐴𝑋 ) = ( 𝐵𝑋 ) )
11 simpl11 ( ( ( ( 𝐴 No 𝐵 No 𝑋 ∈ On ) ∧ ( ( 𝐴𝑋 ) = ( 𝐵𝑋 ) ∧ 𝐴 <s 𝐵 ) ∧ ( 𝐴𝑋 ) = ∅ ) ∧ ( 𝐵𝑋 ) = ∅ ) → 𝐴 No )
12 nofun ( 𝐴 No → Fun 𝐴 )
13 funrel ( Fun 𝐴 → Rel 𝐴 )
14 11 12 13 3syl ( ( ( ( 𝐴 No 𝐵 No 𝑋 ∈ On ) ∧ ( ( 𝐴𝑋 ) = ( 𝐵𝑋 ) ∧ 𝐴 <s 𝐵 ) ∧ ( 𝐴𝑋 ) = ∅ ) ∧ ( 𝐵𝑋 ) = ∅ ) → Rel 𝐴 )
15 simpl13 ( ( ( ( 𝐴 No 𝐵 No 𝑋 ∈ On ) ∧ ( ( 𝐴𝑋 ) = ( 𝐵𝑋 ) ∧ 𝐴 <s 𝐵 ) ∧ ( 𝐴𝑋 ) = ∅ ) ∧ ( 𝐵𝑋 ) = ∅ ) → 𝑋 ∈ On )
16 simpl3 ( ( ( ( 𝐴 No 𝐵 No 𝑋 ∈ On ) ∧ ( ( 𝐴𝑋 ) = ( 𝐵𝑋 ) ∧ 𝐴 <s 𝐵 ) ∧ ( 𝐴𝑋 ) = ∅ ) ∧ ( 𝐵𝑋 ) = ∅ ) → ( 𝐴𝑋 ) = ∅ )
17 nolt02olem ( ( 𝐴 No 𝑋 ∈ On ∧ ( 𝐴𝑋 ) = ∅ ) → dom 𝐴𝑋 )
18 11 15 16 17 syl3anc ( ( ( ( 𝐴 No 𝐵 No 𝑋 ∈ On ) ∧ ( ( 𝐴𝑋 ) = ( 𝐵𝑋 ) ∧ 𝐴 <s 𝐵 ) ∧ ( 𝐴𝑋 ) = ∅ ) ∧ ( 𝐵𝑋 ) = ∅ ) → dom 𝐴𝑋 )
19 relssres ( ( Rel 𝐴 ∧ dom 𝐴𝑋 ) → ( 𝐴𝑋 ) = 𝐴 )
20 14 18 19 syl2anc ( ( ( ( 𝐴 No 𝐵 No 𝑋 ∈ On ) ∧ ( ( 𝐴𝑋 ) = ( 𝐵𝑋 ) ∧ 𝐴 <s 𝐵 ) ∧ ( 𝐴𝑋 ) = ∅ ) ∧ ( 𝐵𝑋 ) = ∅ ) → ( 𝐴𝑋 ) = 𝐴 )
21 simpl12 ( ( ( ( 𝐴 No 𝐵 No 𝑋 ∈ On ) ∧ ( ( 𝐴𝑋 ) = ( 𝐵𝑋 ) ∧ 𝐴 <s 𝐵 ) ∧ ( 𝐴𝑋 ) = ∅ ) ∧ ( 𝐵𝑋 ) = ∅ ) → 𝐵 No )
22 nofun ( 𝐵 No → Fun 𝐵 )
23 funrel ( Fun 𝐵 → Rel 𝐵 )
24 21 22 23 3syl ( ( ( ( 𝐴 No 𝐵 No 𝑋 ∈ On ) ∧ ( ( 𝐴𝑋 ) = ( 𝐵𝑋 ) ∧ 𝐴 <s 𝐵 ) ∧ ( 𝐴𝑋 ) = ∅ ) ∧ ( 𝐵𝑋 ) = ∅ ) → Rel 𝐵 )
25 simpr ( ( ( ( 𝐴 No 𝐵 No 𝑋 ∈ On ) ∧ ( ( 𝐴𝑋 ) = ( 𝐵𝑋 ) ∧ 𝐴 <s 𝐵 ) ∧ ( 𝐴𝑋 ) = ∅ ) ∧ ( 𝐵𝑋 ) = ∅ ) → ( 𝐵𝑋 ) = ∅ )
26 nolt02olem ( ( 𝐵 No 𝑋 ∈ On ∧ ( 𝐵𝑋 ) = ∅ ) → dom 𝐵𝑋 )
27 21 15 25 26 syl3anc ( ( ( ( 𝐴 No 𝐵 No 𝑋 ∈ On ) ∧ ( ( 𝐴𝑋 ) = ( 𝐵𝑋 ) ∧ 𝐴 <s 𝐵 ) ∧ ( 𝐴𝑋 ) = ∅ ) ∧ ( 𝐵𝑋 ) = ∅ ) → dom 𝐵𝑋 )
28 relssres ( ( Rel 𝐵 ∧ dom 𝐵𝑋 ) → ( 𝐵𝑋 ) = 𝐵 )
29 24 27 28 syl2anc ( ( ( ( 𝐴 No 𝐵 No 𝑋 ∈ On ) ∧ ( ( 𝐴𝑋 ) = ( 𝐵𝑋 ) ∧ 𝐴 <s 𝐵 ) ∧ ( 𝐴𝑋 ) = ∅ ) ∧ ( 𝐵𝑋 ) = ∅ ) → ( 𝐵𝑋 ) = 𝐵 )
30 10 20 29 3eqtr3d ( ( ( ( 𝐴 No 𝐵 No 𝑋 ∈ On ) ∧ ( ( 𝐴𝑋 ) = ( 𝐵𝑋 ) ∧ 𝐴 <s 𝐵 ) ∧ ( 𝐴𝑋 ) = ∅ ) ∧ ( 𝐵𝑋 ) = ∅ ) → 𝐴 = 𝐵 )
31 9 30 mtand ( ( ( 𝐴 No 𝐵 No 𝑋 ∈ On ) ∧ ( ( 𝐴𝑋 ) = ( 𝐵𝑋 ) ∧ 𝐴 <s 𝐵 ) ∧ ( 𝐴𝑋 ) = ∅ ) → ¬ ( 𝐵𝑋 ) = ∅ )
32 simp12 ( ( ( 𝐴 No 𝐵 No 𝑋 ∈ On ) ∧ ( ( 𝐴𝑋 ) = ( 𝐵𝑋 ) ∧ 𝐴 <s 𝐵 ) ∧ ( 𝐴𝑋 ) = ∅ ) → 𝐵 No )
33 sltval ( ( 𝐴 No 𝐵 No ) → ( 𝐴 <s 𝐵 ↔ ∃ 𝑥 ∈ On ( ∀ 𝑦𝑥 ( 𝐴𝑦 ) = ( 𝐵𝑦 ) ∧ ( 𝐴𝑥 ) { ⟨ 1o , ∅ ⟩ , ⟨ 1o , 2o ⟩ , ⟨ ∅ , 2o ⟩ } ( 𝐵𝑥 ) ) ) )
34 1 32 33 syl2anc ( ( ( 𝐴 No 𝐵 No 𝑋 ∈ On ) ∧ ( ( 𝐴𝑋 ) = ( 𝐵𝑋 ) ∧ 𝐴 <s 𝐵 ) ∧ ( 𝐴𝑋 ) = ∅ ) → ( 𝐴 <s 𝐵 ↔ ∃ 𝑥 ∈ On ( ∀ 𝑦𝑥 ( 𝐴𝑦 ) = ( 𝐵𝑦 ) ∧ ( 𝐴𝑥 ) { ⟨ 1o , ∅ ⟩ , ⟨ 1o , 2o ⟩ , ⟨ ∅ , 2o ⟩ } ( 𝐵𝑥 ) ) ) )
35 6 34 mpbid ( ( ( 𝐴 No 𝐵 No 𝑋 ∈ On ) ∧ ( ( 𝐴𝑋 ) = ( 𝐵𝑋 ) ∧ 𝐴 <s 𝐵 ) ∧ ( 𝐴𝑋 ) = ∅ ) → ∃ 𝑥 ∈ On ( ∀ 𝑦𝑥 ( 𝐴𝑦 ) = ( 𝐵𝑦 ) ∧ ( 𝐴𝑥 ) { ⟨ 1o , ∅ ⟩ , ⟨ 1o , 2o ⟩ , ⟨ ∅ , 2o ⟩ } ( 𝐵𝑥 ) ) )
36 df-an ( ( ∀ 𝑦𝑥 ( 𝐴𝑦 ) = ( 𝐵𝑦 ) ∧ ( 𝐴𝑥 ) { ⟨ 1o , ∅ ⟩ , ⟨ 1o , 2o ⟩ , ⟨ ∅ , 2o ⟩ } ( 𝐵𝑥 ) ) ↔ ¬ ( ∀ 𝑦𝑥 ( 𝐴𝑦 ) = ( 𝐵𝑦 ) → ¬ ( 𝐴𝑥 ) { ⟨ 1o , ∅ ⟩ , ⟨ 1o , 2o ⟩ , ⟨ ∅ , 2o ⟩ } ( 𝐵𝑥 ) ) )
37 36 rexbii ( ∃ 𝑥 ∈ On ( ∀ 𝑦𝑥 ( 𝐴𝑦 ) = ( 𝐵𝑦 ) ∧ ( 𝐴𝑥 ) { ⟨ 1o , ∅ ⟩ , ⟨ 1o , 2o ⟩ , ⟨ ∅ , 2o ⟩ } ( 𝐵𝑥 ) ) ↔ ∃ 𝑥 ∈ On ¬ ( ∀ 𝑦𝑥 ( 𝐴𝑦 ) = ( 𝐵𝑦 ) → ¬ ( 𝐴𝑥 ) { ⟨ 1o , ∅ ⟩ , ⟨ 1o , 2o ⟩ , ⟨ ∅ , 2o ⟩ } ( 𝐵𝑥 ) ) )
38 rexnal ( ∃ 𝑥 ∈ On ¬ ( ∀ 𝑦𝑥 ( 𝐴𝑦 ) = ( 𝐵𝑦 ) → ¬ ( 𝐴𝑥 ) { ⟨ 1o , ∅ ⟩ , ⟨ 1o , 2o ⟩ , ⟨ ∅ , 2o ⟩ } ( 𝐵𝑥 ) ) ↔ ¬ ∀ 𝑥 ∈ On ( ∀ 𝑦𝑥 ( 𝐴𝑦 ) = ( 𝐵𝑦 ) → ¬ ( 𝐴𝑥 ) { ⟨ 1o , ∅ ⟩ , ⟨ 1o , 2o ⟩ , ⟨ ∅ , 2o ⟩ } ( 𝐵𝑥 ) ) )
39 37 38 bitri ( ∃ 𝑥 ∈ On ( ∀ 𝑦𝑥 ( 𝐴𝑦 ) = ( 𝐵𝑦 ) ∧ ( 𝐴𝑥 ) { ⟨ 1o , ∅ ⟩ , ⟨ 1o , 2o ⟩ , ⟨ ∅ , 2o ⟩ } ( 𝐵𝑥 ) ) ↔ ¬ ∀ 𝑥 ∈ On ( ∀ 𝑦𝑥 ( 𝐴𝑦 ) = ( 𝐵𝑦 ) → ¬ ( 𝐴𝑥 ) { ⟨ 1o , ∅ ⟩ , ⟨ 1o , 2o ⟩ , ⟨ ∅ , 2o ⟩ } ( 𝐵𝑥 ) ) )
40 35 39 sylib ( ( ( 𝐴 No 𝐵 No 𝑋 ∈ On ) ∧ ( ( 𝐴𝑋 ) = ( 𝐵𝑋 ) ∧ 𝐴 <s 𝐵 ) ∧ ( 𝐴𝑋 ) = ∅ ) → ¬ ∀ 𝑥 ∈ On ( ∀ 𝑦𝑥 ( 𝐴𝑦 ) = ( 𝐵𝑦 ) → ¬ ( 𝐴𝑥 ) { ⟨ 1o , ∅ ⟩ , ⟨ 1o , 2o ⟩ , ⟨ ∅ , 2o ⟩ } ( 𝐵𝑥 ) ) )
41 1oex 1o ∈ V
42 41 prid1 1o ∈ { 1o , 2o }
43 42 nosgnn0i ∅ ≠ 1o
44 43 neii ¬ ∅ = 1o
45 simpll3 ( ( ( ( ( 𝐴 No 𝐵 No 𝑋 ∈ On ) ∧ ( ( 𝐴𝑋 ) = ( 𝐵𝑋 ) ∧ 𝐴 <s 𝐵 ) ∧ ( 𝐴𝑋 ) = ∅ ) ∧ ( 𝐵𝑋 ) = 1o ) ∧ ( 𝑥 ∈ On ∧ ∀ 𝑦𝑥 ( 𝐴𝑦 ) = ( 𝐵𝑦 ) ) ) → ( 𝐴𝑋 ) = ∅ )
46 simplr ( ( ( ( ( 𝐴 No 𝐵 No 𝑋 ∈ On ) ∧ ( ( 𝐴𝑋 ) = ( 𝐵𝑋 ) ∧ 𝐴 <s 𝐵 ) ∧ ( 𝐴𝑋 ) = ∅ ) ∧ ( 𝐵𝑋 ) = 1o ) ∧ ( 𝑥 ∈ On ∧ ∀ 𝑦𝑥 ( 𝐴𝑦 ) = ( 𝐵𝑦 ) ) ) → ( 𝐵𝑋 ) = 1o )
47 eqeq1 ( ( 𝐴𝑋 ) = ( 𝐵𝑋 ) → ( ( 𝐴𝑋 ) = ∅ ↔ ( 𝐵𝑋 ) = ∅ ) )
48 47 anbi1d ( ( 𝐴𝑋 ) = ( 𝐵𝑋 ) → ( ( ( 𝐴𝑋 ) = ∅ ∧ ( 𝐵𝑋 ) = 1o ) ↔ ( ( 𝐵𝑋 ) = ∅ ∧ ( 𝐵𝑋 ) = 1o ) ) )
49 eqtr2 ( ( ( 𝐵𝑋 ) = ∅ ∧ ( 𝐵𝑋 ) = 1o ) → ∅ = 1o )
50 48 49 syl6bi ( ( 𝐴𝑋 ) = ( 𝐵𝑋 ) → ( ( ( 𝐴𝑋 ) = ∅ ∧ ( 𝐵𝑋 ) = 1o ) → ∅ = 1o ) )
51 50 com12 ( ( ( 𝐴𝑋 ) = ∅ ∧ ( 𝐵𝑋 ) = 1o ) → ( ( 𝐴𝑋 ) = ( 𝐵𝑋 ) → ∅ = 1o ) )
52 45 46 51 syl2anc ( ( ( ( ( 𝐴 No 𝐵 No 𝑋 ∈ On ) ∧ ( ( 𝐴𝑋 ) = ( 𝐵𝑋 ) ∧ 𝐴 <s 𝐵 ) ∧ ( 𝐴𝑋 ) = ∅ ) ∧ ( 𝐵𝑋 ) = 1o ) ∧ ( 𝑥 ∈ On ∧ ∀ 𝑦𝑥 ( 𝐴𝑦 ) = ( 𝐵𝑦 ) ) ) → ( ( 𝐴𝑋 ) = ( 𝐵𝑋 ) → ∅ = 1o ) )
53 44 52 mtoi ( ( ( ( ( 𝐴 No 𝐵 No 𝑋 ∈ On ) ∧ ( ( 𝐴𝑋 ) = ( 𝐵𝑋 ) ∧ 𝐴 <s 𝐵 ) ∧ ( 𝐴𝑋 ) = ∅ ) ∧ ( 𝐵𝑋 ) = 1o ) ∧ ( 𝑥 ∈ On ∧ ∀ 𝑦𝑥 ( 𝐴𝑦 ) = ( 𝐵𝑦 ) ) ) → ¬ ( 𝐴𝑋 ) = ( 𝐵𝑋 ) )
54 simpr ( ( ( ( ( ( 𝐴 No 𝐵 No 𝑋 ∈ On ) ∧ ( ( 𝐴𝑋 ) = ( 𝐵𝑋 ) ∧ 𝐴 <s 𝐵 ) ∧ ( 𝐴𝑋 ) = ∅ ) ∧ ( 𝐵𝑋 ) = 1o ) ∧ ( 𝑥 ∈ On ∧ ∀ 𝑦𝑥 ( 𝐴𝑦 ) = ( 𝐵𝑦 ) ) ) ∧ 𝑋𝑥 ) → 𝑋𝑥 )
55 simplrr ( ( ( ( ( ( 𝐴 No 𝐵 No 𝑋 ∈ On ) ∧ ( ( 𝐴𝑋 ) = ( 𝐵𝑋 ) ∧ 𝐴 <s 𝐵 ) ∧ ( 𝐴𝑋 ) = ∅ ) ∧ ( 𝐵𝑋 ) = 1o ) ∧ ( 𝑥 ∈ On ∧ ∀ 𝑦𝑥 ( 𝐴𝑦 ) = ( 𝐵𝑦 ) ) ) ∧ 𝑋𝑥 ) → ∀ 𝑦𝑥 ( 𝐴𝑦 ) = ( 𝐵𝑦 ) )
56 fveq2 ( 𝑦 = 𝑋 → ( 𝐴𝑦 ) = ( 𝐴𝑋 ) )
57 fveq2 ( 𝑦 = 𝑋 → ( 𝐵𝑦 ) = ( 𝐵𝑋 ) )
58 56 57 eqeq12d ( 𝑦 = 𝑋 → ( ( 𝐴𝑦 ) = ( 𝐵𝑦 ) ↔ ( 𝐴𝑋 ) = ( 𝐵𝑋 ) ) )
59 58 rspcv ( 𝑋𝑥 → ( ∀ 𝑦𝑥 ( 𝐴𝑦 ) = ( 𝐵𝑦 ) → ( 𝐴𝑋 ) = ( 𝐵𝑋 ) ) )
60 54 55 59 sylc ( ( ( ( ( ( 𝐴 No 𝐵 No 𝑋 ∈ On ) ∧ ( ( 𝐴𝑋 ) = ( 𝐵𝑋 ) ∧ 𝐴 <s 𝐵 ) ∧ ( 𝐴𝑋 ) = ∅ ) ∧ ( 𝐵𝑋 ) = 1o ) ∧ ( 𝑥 ∈ On ∧ ∀ 𝑦𝑥 ( 𝐴𝑦 ) = ( 𝐵𝑦 ) ) ) ∧ 𝑋𝑥 ) → ( 𝐴𝑋 ) = ( 𝐵𝑋 ) )
61 53 60 mtand ( ( ( ( ( 𝐴 No 𝐵 No 𝑋 ∈ On ) ∧ ( ( 𝐴𝑋 ) = ( 𝐵𝑋 ) ∧ 𝐴 <s 𝐵 ) ∧ ( 𝐴𝑋 ) = ∅ ) ∧ ( 𝐵𝑋 ) = 1o ) ∧ ( 𝑥 ∈ On ∧ ∀ 𝑦𝑥 ( 𝐴𝑦 ) = ( 𝐵𝑦 ) ) ) → ¬ 𝑋𝑥 )
62 simprl ( ( ( ( ( 𝐴 No 𝐵 No 𝑋 ∈ On ) ∧ ( ( 𝐴𝑋 ) = ( 𝐵𝑋 ) ∧ 𝐴 <s 𝐵 ) ∧ ( 𝐴𝑋 ) = ∅ ) ∧ ( 𝐵𝑋 ) = 1o ) ∧ ( 𝑥 ∈ On ∧ ∀ 𝑦𝑥 ( 𝐴𝑦 ) = ( 𝐵𝑦 ) ) ) → 𝑥 ∈ On )
63 simpl13 ( ( ( ( 𝐴 No 𝐵 No 𝑋 ∈ On ) ∧ ( ( 𝐴𝑋 ) = ( 𝐵𝑋 ) ∧ 𝐴 <s 𝐵 ) ∧ ( 𝐴𝑋 ) = ∅ ) ∧ ( 𝐵𝑋 ) = 1o ) → 𝑋 ∈ On )
64 63 adantr ( ( ( ( ( 𝐴 No 𝐵 No 𝑋 ∈ On ) ∧ ( ( 𝐴𝑋 ) = ( 𝐵𝑋 ) ∧ 𝐴 <s 𝐵 ) ∧ ( 𝐴𝑋 ) = ∅ ) ∧ ( 𝐵𝑋 ) = 1o ) ∧ ( 𝑥 ∈ On ∧ ∀ 𝑦𝑥 ( 𝐴𝑦 ) = ( 𝐵𝑦 ) ) ) → 𝑋 ∈ On )
65 ontri1 ( ( 𝑥 ∈ On ∧ 𝑋 ∈ On ) → ( 𝑥𝑋 ↔ ¬ 𝑋𝑥 ) )
66 62 64 65 syl2anc ( ( ( ( ( 𝐴 No 𝐵 No 𝑋 ∈ On ) ∧ ( ( 𝐴𝑋 ) = ( 𝐵𝑋 ) ∧ 𝐴 <s 𝐵 ) ∧ ( 𝐴𝑋 ) = ∅ ) ∧ ( 𝐵𝑋 ) = 1o ) ∧ ( 𝑥 ∈ On ∧ ∀ 𝑦𝑥 ( 𝐴𝑦 ) = ( 𝐵𝑦 ) ) ) → ( 𝑥𝑋 ↔ ¬ 𝑋𝑥 ) )
67 61 66 mpbird ( ( ( ( ( 𝐴 No 𝐵 No 𝑋 ∈ On ) ∧ ( ( 𝐴𝑋 ) = ( 𝐵𝑋 ) ∧ 𝐴 <s 𝐵 ) ∧ ( 𝐴𝑋 ) = ∅ ) ∧ ( 𝐵𝑋 ) = 1o ) ∧ ( 𝑥 ∈ On ∧ ∀ 𝑦𝑥 ( 𝐴𝑦 ) = ( 𝐵𝑦 ) ) ) → 𝑥𝑋 )
68 onsseleq ( ( 𝑥 ∈ On ∧ 𝑋 ∈ On ) → ( 𝑥𝑋 ↔ ( 𝑥𝑋𝑥 = 𝑋 ) ) )
69 62 64 68 syl2anc ( ( ( ( ( 𝐴 No 𝐵 No 𝑋 ∈ On ) ∧ ( ( 𝐴𝑋 ) = ( 𝐵𝑋 ) ∧ 𝐴 <s 𝐵 ) ∧ ( 𝐴𝑋 ) = ∅ ) ∧ ( 𝐵𝑋 ) = 1o ) ∧ ( 𝑥 ∈ On ∧ ∀ 𝑦𝑥 ( 𝐴𝑦 ) = ( 𝐵𝑦 ) ) ) → ( 𝑥𝑋 ↔ ( 𝑥𝑋𝑥 = 𝑋 ) ) )
70 eqtr2 ( ( ( ( 𝐴𝑋 ) ‘ 𝑥 ) = ∅ ∧ ( ( 𝐴𝑋 ) ‘ 𝑥 ) = 1o ) → ∅ = 1o )
71 70 ancoms ( ( ( ( 𝐴𝑋 ) ‘ 𝑥 ) = 1o ∧ ( ( 𝐴𝑋 ) ‘ 𝑥 ) = ∅ ) → ∅ = 1o )
72 44 71 mto ¬ ( ( ( 𝐴𝑋 ) ‘ 𝑥 ) = 1o ∧ ( ( 𝐴𝑋 ) ‘ 𝑥 ) = ∅ )
73 df-1o 1o = suc ∅
74 df-2o 2o = suc 1o
75 73 74 eqeq12i ( 1o = 2o ↔ suc ∅ = suc 1o )
76 0elon ∅ ∈ On
77 1on 1o ∈ On
78 suc11 ( ( ∅ ∈ On ∧ 1o ∈ On ) → ( suc ∅ = suc 1o ↔ ∅ = 1o ) )
79 76 77 78 mp2an ( suc ∅ = suc 1o ↔ ∅ = 1o )
80 75 79 bitri ( 1o = 2o ↔ ∅ = 1o )
81 43 80 nemtbir ¬ 1o = 2o
82 eqtr2 ( ( ( ( 𝐴𝑋 ) ‘ 𝑥 ) = 1o ∧ ( ( 𝐴𝑋 ) ‘ 𝑥 ) = 2o ) → 1o = 2o )
83 81 82 mto ¬ ( ( ( 𝐴𝑋 ) ‘ 𝑥 ) = 1o ∧ ( ( 𝐴𝑋 ) ‘ 𝑥 ) = 2o )
84 2on 2o ∈ On
85 84 elexi 2o ∈ V
86 85 prid2 2o ∈ { 1o , 2o }
87 86 nosgnn0i ∅ ≠ 2o
88 87 neii ¬ ∅ = 2o
89 eqtr2 ( ( ( ( 𝐴𝑋 ) ‘ 𝑥 ) = ∅ ∧ ( ( 𝐴𝑋 ) ‘ 𝑥 ) = 2o ) → ∅ = 2o )
90 88 89 mto ¬ ( ( ( 𝐴𝑋 ) ‘ 𝑥 ) = ∅ ∧ ( ( 𝐴𝑋 ) ‘ 𝑥 ) = 2o )
91 72 83 90 3pm3.2i ( ¬ ( ( ( 𝐴𝑋 ) ‘ 𝑥 ) = 1o ∧ ( ( 𝐴𝑋 ) ‘ 𝑥 ) = ∅ ) ∧ ¬ ( ( ( 𝐴𝑋 ) ‘ 𝑥 ) = 1o ∧ ( ( 𝐴𝑋 ) ‘ 𝑥 ) = 2o ) ∧ ¬ ( ( ( 𝐴𝑋 ) ‘ 𝑥 ) = ∅ ∧ ( ( 𝐴𝑋 ) ‘ 𝑥 ) = 2o ) )
92 fvex ( ( 𝐴𝑋 ) ‘ 𝑥 ) ∈ V
93 92 92 brtp ( ( ( 𝐴𝑋 ) ‘ 𝑥 ) { ⟨ 1o , ∅ ⟩ , ⟨ 1o , 2o ⟩ , ⟨ ∅ , 2o ⟩ } ( ( 𝐴𝑋 ) ‘ 𝑥 ) ↔ ( ( ( ( 𝐴𝑋 ) ‘ 𝑥 ) = 1o ∧ ( ( 𝐴𝑋 ) ‘ 𝑥 ) = ∅ ) ∨ ( ( ( 𝐴𝑋 ) ‘ 𝑥 ) = 1o ∧ ( ( 𝐴𝑋 ) ‘ 𝑥 ) = 2o ) ∨ ( ( ( 𝐴𝑋 ) ‘ 𝑥 ) = ∅ ∧ ( ( 𝐴𝑋 ) ‘ 𝑥 ) = 2o ) ) )
94 3oran ( ( ( ( ( 𝐴𝑋 ) ‘ 𝑥 ) = 1o ∧ ( ( 𝐴𝑋 ) ‘ 𝑥 ) = ∅ ) ∨ ( ( ( 𝐴𝑋 ) ‘ 𝑥 ) = 1o ∧ ( ( 𝐴𝑋 ) ‘ 𝑥 ) = 2o ) ∨ ( ( ( 𝐴𝑋 ) ‘ 𝑥 ) = ∅ ∧ ( ( 𝐴𝑋 ) ‘ 𝑥 ) = 2o ) ) ↔ ¬ ( ¬ ( ( ( 𝐴𝑋 ) ‘ 𝑥 ) = 1o ∧ ( ( 𝐴𝑋 ) ‘ 𝑥 ) = ∅ ) ∧ ¬ ( ( ( 𝐴𝑋 ) ‘ 𝑥 ) = 1o ∧ ( ( 𝐴𝑋 ) ‘ 𝑥 ) = 2o ) ∧ ¬ ( ( ( 𝐴𝑋 ) ‘ 𝑥 ) = ∅ ∧ ( ( 𝐴𝑋 ) ‘ 𝑥 ) = 2o ) ) )
95 93 94 bitri ( ( ( 𝐴𝑋 ) ‘ 𝑥 ) { ⟨ 1o , ∅ ⟩ , ⟨ 1o , 2o ⟩ , ⟨ ∅ , 2o ⟩ } ( ( 𝐴𝑋 ) ‘ 𝑥 ) ↔ ¬ ( ¬ ( ( ( 𝐴𝑋 ) ‘ 𝑥 ) = 1o ∧ ( ( 𝐴𝑋 ) ‘ 𝑥 ) = ∅ ) ∧ ¬ ( ( ( 𝐴𝑋 ) ‘ 𝑥 ) = 1o ∧ ( ( 𝐴𝑋 ) ‘ 𝑥 ) = 2o ) ∧ ¬ ( ( ( 𝐴𝑋 ) ‘ 𝑥 ) = ∅ ∧ ( ( 𝐴𝑋 ) ‘ 𝑥 ) = 2o ) ) )
96 95 con2bii ( ( ¬ ( ( ( 𝐴𝑋 ) ‘ 𝑥 ) = 1o ∧ ( ( 𝐴𝑋 ) ‘ 𝑥 ) = ∅ ) ∧ ¬ ( ( ( 𝐴𝑋 ) ‘ 𝑥 ) = 1o ∧ ( ( 𝐴𝑋 ) ‘ 𝑥 ) = 2o ) ∧ ¬ ( ( ( 𝐴𝑋 ) ‘ 𝑥 ) = ∅ ∧ ( ( 𝐴𝑋 ) ‘ 𝑥 ) = 2o ) ) ↔ ¬ ( ( 𝐴𝑋 ) ‘ 𝑥 ) { ⟨ 1o , ∅ ⟩ , ⟨ 1o , 2o ⟩ , ⟨ ∅ , 2o ⟩ } ( ( 𝐴𝑋 ) ‘ 𝑥 ) )
97 91 96 mpbi ¬ ( ( 𝐴𝑋 ) ‘ 𝑥 ) { ⟨ 1o , ∅ ⟩ , ⟨ 1o , 2o ⟩ , ⟨ ∅ , 2o ⟩ } ( ( 𝐴𝑋 ) ‘ 𝑥 )
98 simpl2l ( ( ( ( 𝐴 No 𝐵 No 𝑋 ∈ On ) ∧ ( ( 𝐴𝑋 ) = ( 𝐵𝑋 ) ∧ 𝐴 <s 𝐵 ) ∧ ( 𝐴𝑋 ) = ∅ ) ∧ ( 𝐵𝑋 ) = 1o ) → ( 𝐴𝑋 ) = ( 𝐵𝑋 ) )
99 98 adantr ( ( ( ( ( 𝐴 No 𝐵 No 𝑋 ∈ On ) ∧ ( ( 𝐴𝑋 ) = ( 𝐵𝑋 ) ∧ 𝐴 <s 𝐵 ) ∧ ( 𝐴𝑋 ) = ∅ ) ∧ ( 𝐵𝑋 ) = 1o ) ∧ ( 𝑥 ∈ On ∧ ∀ 𝑦𝑥 ( 𝐴𝑦 ) = ( 𝐵𝑦 ) ) ) → ( 𝐴𝑋 ) = ( 𝐵𝑋 ) )
100 99 fveq1d ( ( ( ( ( 𝐴 No 𝐵 No 𝑋 ∈ On ) ∧ ( ( 𝐴𝑋 ) = ( 𝐵𝑋 ) ∧ 𝐴 <s 𝐵 ) ∧ ( 𝐴𝑋 ) = ∅ ) ∧ ( 𝐵𝑋 ) = 1o ) ∧ ( 𝑥 ∈ On ∧ ∀ 𝑦𝑥 ( 𝐴𝑦 ) = ( 𝐵𝑦 ) ) ) → ( ( 𝐴𝑋 ) ‘ 𝑥 ) = ( ( 𝐵𝑋 ) ‘ 𝑥 ) )
101 100 breq2d ( ( ( ( ( 𝐴 No 𝐵 No 𝑋 ∈ On ) ∧ ( ( 𝐴𝑋 ) = ( 𝐵𝑋 ) ∧ 𝐴 <s 𝐵 ) ∧ ( 𝐴𝑋 ) = ∅ ) ∧ ( 𝐵𝑋 ) = 1o ) ∧ ( 𝑥 ∈ On ∧ ∀ 𝑦𝑥 ( 𝐴𝑦 ) = ( 𝐵𝑦 ) ) ) → ( ( ( 𝐴𝑋 ) ‘ 𝑥 ) { ⟨ 1o , ∅ ⟩ , ⟨ 1o , 2o ⟩ , ⟨ ∅ , 2o ⟩ } ( ( 𝐴𝑋 ) ‘ 𝑥 ) ↔ ( ( 𝐴𝑋 ) ‘ 𝑥 ) { ⟨ 1o , ∅ ⟩ , ⟨ 1o , 2o ⟩ , ⟨ ∅ , 2o ⟩ } ( ( 𝐵𝑋 ) ‘ 𝑥 ) ) )
102 97 101 mtbii ( ( ( ( ( 𝐴 No 𝐵 No 𝑋 ∈ On ) ∧ ( ( 𝐴𝑋 ) = ( 𝐵𝑋 ) ∧ 𝐴 <s 𝐵 ) ∧ ( 𝐴𝑋 ) = ∅ ) ∧ ( 𝐵𝑋 ) = 1o ) ∧ ( 𝑥 ∈ On ∧ ∀ 𝑦𝑥 ( 𝐴𝑦 ) = ( 𝐵𝑦 ) ) ) → ¬ ( ( 𝐴𝑋 ) ‘ 𝑥 ) { ⟨ 1o , ∅ ⟩ , ⟨ 1o , 2o ⟩ , ⟨ ∅ , 2o ⟩ } ( ( 𝐵𝑋 ) ‘ 𝑥 ) )
103 fvres ( 𝑥𝑋 → ( ( 𝐴𝑋 ) ‘ 𝑥 ) = ( 𝐴𝑥 ) )
104 fvres ( 𝑥𝑋 → ( ( 𝐵𝑋 ) ‘ 𝑥 ) = ( 𝐵𝑥 ) )
105 103 104 breq12d ( 𝑥𝑋 → ( ( ( 𝐴𝑋 ) ‘ 𝑥 ) { ⟨ 1o , ∅ ⟩ , ⟨ 1o , 2o ⟩ , ⟨ ∅ , 2o ⟩ } ( ( 𝐵𝑋 ) ‘ 𝑥 ) ↔ ( 𝐴𝑥 ) { ⟨ 1o , ∅ ⟩ , ⟨ 1o , 2o ⟩ , ⟨ ∅ , 2o ⟩ } ( 𝐵𝑥 ) ) )
106 105 notbid ( 𝑥𝑋 → ( ¬ ( ( 𝐴𝑋 ) ‘ 𝑥 ) { ⟨ 1o , ∅ ⟩ , ⟨ 1o , 2o ⟩ , ⟨ ∅ , 2o ⟩ } ( ( 𝐵𝑋 ) ‘ 𝑥 ) ↔ ¬ ( 𝐴𝑥 ) { ⟨ 1o , ∅ ⟩ , ⟨ 1o , 2o ⟩ , ⟨ ∅ , 2o ⟩ } ( 𝐵𝑥 ) ) )
107 102 106 syl5ibcom ( ( ( ( ( 𝐴 No 𝐵 No 𝑋 ∈ On ) ∧ ( ( 𝐴𝑋 ) = ( 𝐵𝑋 ) ∧ 𝐴 <s 𝐵 ) ∧ ( 𝐴𝑋 ) = ∅ ) ∧ ( 𝐵𝑋 ) = 1o ) ∧ ( 𝑥 ∈ On ∧ ∀ 𝑦𝑥 ( 𝐴𝑦 ) = ( 𝐵𝑦 ) ) ) → ( 𝑥𝑋 → ¬ ( 𝐴𝑥 ) { ⟨ 1o , ∅ ⟩ , ⟨ 1o , 2o ⟩ , ⟨ ∅ , 2o ⟩ } ( 𝐵𝑥 ) ) )
108 44 intnanr ¬ ( ∅ = 1o ∧ 1o = ∅ )
109 44 intnanr ¬ ( ∅ = 1o ∧ 1o = 2o )
110 81 intnan ¬ ( ∅ = ∅ ∧ 1o = 2o )
111 108 109 110 3pm3.2i ( ¬ ( ∅ = 1o ∧ 1o = ∅ ) ∧ ¬ ( ∅ = 1o ∧ 1o = 2o ) ∧ ¬ ( ∅ = ∅ ∧ 1o = 2o ) )
112 0ex ∅ ∈ V
113 112 41 brtp ( ∅ { ⟨ 1o , ∅ ⟩ , ⟨ 1o , 2o ⟩ , ⟨ ∅ , 2o ⟩ } 1o ↔ ( ( ∅ = 1o ∧ 1o = ∅ ) ∨ ( ∅ = 1o ∧ 1o = 2o ) ∨ ( ∅ = ∅ ∧ 1o = 2o ) ) )
114 3oran ( ( ( ∅ = 1o ∧ 1o = ∅ ) ∨ ( ∅ = 1o ∧ 1o = 2o ) ∨ ( ∅ = ∅ ∧ 1o = 2o ) ) ↔ ¬ ( ¬ ( ∅ = 1o ∧ 1o = ∅ ) ∧ ¬ ( ∅ = 1o ∧ 1o = 2o ) ∧ ¬ ( ∅ = ∅ ∧ 1o = 2o ) ) )
115 113 114 bitri ( ∅ { ⟨ 1o , ∅ ⟩ , ⟨ 1o , 2o ⟩ , ⟨ ∅ , 2o ⟩ } 1o ↔ ¬ ( ¬ ( ∅ = 1o ∧ 1o = ∅ ) ∧ ¬ ( ∅ = 1o ∧ 1o = 2o ) ∧ ¬ ( ∅ = ∅ ∧ 1o = 2o ) ) )
116 115 con2bii ( ( ¬ ( ∅ = 1o ∧ 1o = ∅ ) ∧ ¬ ( ∅ = 1o ∧ 1o = 2o ) ∧ ¬ ( ∅ = ∅ ∧ 1o = 2o ) ) ↔ ¬ ∅ { ⟨ 1o , ∅ ⟩ , ⟨ 1o , 2o ⟩ , ⟨ ∅ , 2o ⟩ } 1o )
117 111 116 mpbi ¬ ∅ { ⟨ 1o , ∅ ⟩ , ⟨ 1o , 2o ⟩ , ⟨ ∅ , 2o ⟩ } 1o
118 45 46 breq12d ( ( ( ( ( 𝐴 No 𝐵 No 𝑋 ∈ On ) ∧ ( ( 𝐴𝑋 ) = ( 𝐵𝑋 ) ∧ 𝐴 <s 𝐵 ) ∧ ( 𝐴𝑋 ) = ∅ ) ∧ ( 𝐵𝑋 ) = 1o ) ∧ ( 𝑥 ∈ On ∧ ∀ 𝑦𝑥 ( 𝐴𝑦 ) = ( 𝐵𝑦 ) ) ) → ( ( 𝐴𝑋 ) { ⟨ 1o , ∅ ⟩ , ⟨ 1o , 2o ⟩ , ⟨ ∅ , 2o ⟩ } ( 𝐵𝑋 ) ↔ ∅ { ⟨ 1o , ∅ ⟩ , ⟨ 1o , 2o ⟩ , ⟨ ∅ , 2o ⟩ } 1o ) )
119 117 118 mtbiri ( ( ( ( ( 𝐴 No 𝐵 No 𝑋 ∈ On ) ∧ ( ( 𝐴𝑋 ) = ( 𝐵𝑋 ) ∧ 𝐴 <s 𝐵 ) ∧ ( 𝐴𝑋 ) = ∅ ) ∧ ( 𝐵𝑋 ) = 1o ) ∧ ( 𝑥 ∈ On ∧ ∀ 𝑦𝑥 ( 𝐴𝑦 ) = ( 𝐵𝑦 ) ) ) → ¬ ( 𝐴𝑋 ) { ⟨ 1o , ∅ ⟩ , ⟨ 1o , 2o ⟩ , ⟨ ∅ , 2o ⟩ } ( 𝐵𝑋 ) )
120 fveq2 ( 𝑥 = 𝑋 → ( 𝐴𝑥 ) = ( 𝐴𝑋 ) )
121 fveq2 ( 𝑥 = 𝑋 → ( 𝐵𝑥 ) = ( 𝐵𝑋 ) )
122 120 121 breq12d ( 𝑥 = 𝑋 → ( ( 𝐴𝑥 ) { ⟨ 1o , ∅ ⟩ , ⟨ 1o , 2o ⟩ , ⟨ ∅ , 2o ⟩ } ( 𝐵𝑥 ) ↔ ( 𝐴𝑋 ) { ⟨ 1o , ∅ ⟩ , ⟨ 1o , 2o ⟩ , ⟨ ∅ , 2o ⟩ } ( 𝐵𝑋 ) ) )
123 122 notbid ( 𝑥 = 𝑋 → ( ¬ ( 𝐴𝑥 ) { ⟨ 1o , ∅ ⟩ , ⟨ 1o , 2o ⟩ , ⟨ ∅ , 2o ⟩ } ( 𝐵𝑥 ) ↔ ¬ ( 𝐴𝑋 ) { ⟨ 1o , ∅ ⟩ , ⟨ 1o , 2o ⟩ , ⟨ ∅ , 2o ⟩ } ( 𝐵𝑋 ) ) )
124 119 123 syl5ibrcom ( ( ( ( ( 𝐴 No 𝐵 No 𝑋 ∈ On ) ∧ ( ( 𝐴𝑋 ) = ( 𝐵𝑋 ) ∧ 𝐴 <s 𝐵 ) ∧ ( 𝐴𝑋 ) = ∅ ) ∧ ( 𝐵𝑋 ) = 1o ) ∧ ( 𝑥 ∈ On ∧ ∀ 𝑦𝑥 ( 𝐴𝑦 ) = ( 𝐵𝑦 ) ) ) → ( 𝑥 = 𝑋 → ¬ ( 𝐴𝑥 ) { ⟨ 1o , ∅ ⟩ , ⟨ 1o , 2o ⟩ , ⟨ ∅ , 2o ⟩ } ( 𝐵𝑥 ) ) )
125 107 124 jaod ( ( ( ( ( 𝐴 No 𝐵 No 𝑋 ∈ On ) ∧ ( ( 𝐴𝑋 ) = ( 𝐵𝑋 ) ∧ 𝐴 <s 𝐵 ) ∧ ( 𝐴𝑋 ) = ∅ ) ∧ ( 𝐵𝑋 ) = 1o ) ∧ ( 𝑥 ∈ On ∧ ∀ 𝑦𝑥 ( 𝐴𝑦 ) = ( 𝐵𝑦 ) ) ) → ( ( 𝑥𝑋𝑥 = 𝑋 ) → ¬ ( 𝐴𝑥 ) { ⟨ 1o , ∅ ⟩ , ⟨ 1o , 2o ⟩ , ⟨ ∅ , 2o ⟩ } ( 𝐵𝑥 ) ) )
126 69 125 sylbid ( ( ( ( ( 𝐴 No 𝐵 No 𝑋 ∈ On ) ∧ ( ( 𝐴𝑋 ) = ( 𝐵𝑋 ) ∧ 𝐴 <s 𝐵 ) ∧ ( 𝐴𝑋 ) = ∅ ) ∧ ( 𝐵𝑋 ) = 1o ) ∧ ( 𝑥 ∈ On ∧ ∀ 𝑦𝑥 ( 𝐴𝑦 ) = ( 𝐵𝑦 ) ) ) → ( 𝑥𝑋 → ¬ ( 𝐴𝑥 ) { ⟨ 1o , ∅ ⟩ , ⟨ 1o , 2o ⟩ , ⟨ ∅ , 2o ⟩ } ( 𝐵𝑥 ) ) )
127 67 126 mpd ( ( ( ( ( 𝐴 No 𝐵 No 𝑋 ∈ On ) ∧ ( ( 𝐴𝑋 ) = ( 𝐵𝑋 ) ∧ 𝐴 <s 𝐵 ) ∧ ( 𝐴𝑋 ) = ∅ ) ∧ ( 𝐵𝑋 ) = 1o ) ∧ ( 𝑥 ∈ On ∧ ∀ 𝑦𝑥 ( 𝐴𝑦 ) = ( 𝐵𝑦 ) ) ) → ¬ ( 𝐴𝑥 ) { ⟨ 1o , ∅ ⟩ , ⟨ 1o , 2o ⟩ , ⟨ ∅ , 2o ⟩ } ( 𝐵𝑥 ) )
128 127 expr ( ( ( ( ( 𝐴 No 𝐵 No 𝑋 ∈ On ) ∧ ( ( 𝐴𝑋 ) = ( 𝐵𝑋 ) ∧ 𝐴 <s 𝐵 ) ∧ ( 𝐴𝑋 ) = ∅ ) ∧ ( 𝐵𝑋 ) = 1o ) ∧ 𝑥 ∈ On ) → ( ∀ 𝑦𝑥 ( 𝐴𝑦 ) = ( 𝐵𝑦 ) → ¬ ( 𝐴𝑥 ) { ⟨ 1o , ∅ ⟩ , ⟨ 1o , 2o ⟩ , ⟨ ∅ , 2o ⟩ } ( 𝐵𝑥 ) ) )
129 128 ralrimiva ( ( ( ( 𝐴 No 𝐵 No 𝑋 ∈ On ) ∧ ( ( 𝐴𝑋 ) = ( 𝐵𝑋 ) ∧ 𝐴 <s 𝐵 ) ∧ ( 𝐴𝑋 ) = ∅ ) ∧ ( 𝐵𝑋 ) = 1o ) → ∀ 𝑥 ∈ On ( ∀ 𝑦𝑥 ( 𝐴𝑦 ) = ( 𝐵𝑦 ) → ¬ ( 𝐴𝑥 ) { ⟨ 1o , ∅ ⟩ , ⟨ 1o , 2o ⟩ , ⟨ ∅ , 2o ⟩ } ( 𝐵𝑥 ) ) )
130 40 129 mtand ( ( ( 𝐴 No 𝐵 No 𝑋 ∈ On ) ∧ ( ( 𝐴𝑋 ) = ( 𝐵𝑋 ) ∧ 𝐴 <s 𝐵 ) ∧ ( 𝐴𝑋 ) = ∅ ) → ¬ ( 𝐵𝑋 ) = 1o )
131 nofv ( 𝐵 No → ( ( 𝐵𝑋 ) = ∅ ∨ ( 𝐵𝑋 ) = 1o ∨ ( 𝐵𝑋 ) = 2o ) )
132 32 131 syl ( ( ( 𝐴 No 𝐵 No 𝑋 ∈ On ) ∧ ( ( 𝐴𝑋 ) = ( 𝐵𝑋 ) ∧ 𝐴 <s 𝐵 ) ∧ ( 𝐴𝑋 ) = ∅ ) → ( ( 𝐵𝑋 ) = ∅ ∨ ( 𝐵𝑋 ) = 1o ∨ ( 𝐵𝑋 ) = 2o ) )
133 3orrot ( ( ( 𝐵𝑋 ) = ∅ ∨ ( 𝐵𝑋 ) = 1o ∨ ( 𝐵𝑋 ) = 2o ) ↔ ( ( 𝐵𝑋 ) = 1o ∨ ( 𝐵𝑋 ) = 2o ∨ ( 𝐵𝑋 ) = ∅ ) )
134 3orrot ( ( ( 𝐵𝑋 ) = 1o ∨ ( 𝐵𝑋 ) = 2o ∨ ( 𝐵𝑋 ) = ∅ ) ↔ ( ( 𝐵𝑋 ) = 2o ∨ ( 𝐵𝑋 ) = ∅ ∨ ( 𝐵𝑋 ) = 1o ) )
135 133 134 bitri ( ( ( 𝐵𝑋 ) = ∅ ∨ ( 𝐵𝑋 ) = 1o ∨ ( 𝐵𝑋 ) = 2o ) ↔ ( ( 𝐵𝑋 ) = 2o ∨ ( 𝐵𝑋 ) = ∅ ∨ ( 𝐵𝑋 ) = 1o ) )
136 132 135 sylib ( ( ( 𝐴 No 𝐵 No 𝑋 ∈ On ) ∧ ( ( 𝐴𝑋 ) = ( 𝐵𝑋 ) ∧ 𝐴 <s 𝐵 ) ∧ ( 𝐴𝑋 ) = ∅ ) → ( ( 𝐵𝑋 ) = 2o ∨ ( 𝐵𝑋 ) = ∅ ∨ ( 𝐵𝑋 ) = 1o ) )
137 31 130 136 ecase23d ( ( ( 𝐴 No 𝐵 No 𝑋 ∈ On ) ∧ ( ( 𝐴𝑋 ) = ( 𝐵𝑋 ) ∧ 𝐴 <s 𝐵 ) ∧ ( 𝐴𝑋 ) = ∅ ) → ( 𝐵𝑋 ) = 2o )