Metamath Proof Explorer


Theorem frgpnabllem1

Description: Lemma for frgpnabl . (Contributed by Mario Carneiro, 21-Apr-2016) (Revised by AV, 25-Apr-2024)

Ref Expression
Hypotheses frgpnabl.g 𝐺 = ( freeGrp ‘ 𝐼 )
frgpnabl.w 𝑊 = ( I ‘ Word ( 𝐼 × 2o ) )
frgpnabl.r = ( ~FG𝐼 )
frgpnabl.p + = ( +g𝐺 )
frgpnabl.m 𝑀 = ( 𝑦𝐼 , 𝑧 ∈ 2o ↦ ⟨ 𝑦 , ( 1o𝑧 ) ⟩ )
frgpnabl.t 𝑇 = ( 𝑣𝑊 ↦ ( 𝑛 ∈ ( 0 ... ( ♯ ‘ 𝑣 ) ) , 𝑤 ∈ ( 𝐼 × 2o ) ↦ ( 𝑣 splice ⟨ 𝑛 , 𝑛 , ⟨“ 𝑤 ( 𝑀𝑤 ) ”⟩ ⟩ ) ) )
frgpnabl.d 𝐷 = ( 𝑊 𝑥𝑊 ran ( 𝑇𝑥 ) )
frgpnabl.u 𝑈 = ( varFGrp𝐼 )
frgpnabl.i ( 𝜑𝐼𝑉 )
frgpnabl.a ( 𝜑𝐴𝐼 )
frgpnabl.b ( 𝜑𝐵𝐼 )
Assertion frgpnabllem1 ( 𝜑 → ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ ∈ ( 𝐷 ∩ ( ( 𝑈𝐴 ) + ( 𝑈𝐵 ) ) ) )

Proof

Step Hyp Ref Expression
1 frgpnabl.g 𝐺 = ( freeGrp ‘ 𝐼 )
2 frgpnabl.w 𝑊 = ( I ‘ Word ( 𝐼 × 2o ) )
3 frgpnabl.r = ( ~FG𝐼 )
4 frgpnabl.p + = ( +g𝐺 )
5 frgpnabl.m 𝑀 = ( 𝑦𝐼 , 𝑧 ∈ 2o ↦ ⟨ 𝑦 , ( 1o𝑧 ) ⟩ )
6 frgpnabl.t 𝑇 = ( 𝑣𝑊 ↦ ( 𝑛 ∈ ( 0 ... ( ♯ ‘ 𝑣 ) ) , 𝑤 ∈ ( 𝐼 × 2o ) ↦ ( 𝑣 splice ⟨ 𝑛 , 𝑛 , ⟨“ 𝑤 ( 𝑀𝑤 ) ”⟩ ⟩ ) ) )
7 frgpnabl.d 𝐷 = ( 𝑊 𝑥𝑊 ran ( 𝑇𝑥 ) )
8 frgpnabl.u 𝑈 = ( varFGrp𝐼 )
9 frgpnabl.i ( 𝜑𝐼𝑉 )
10 frgpnabl.a ( 𝜑𝐴𝐼 )
11 frgpnabl.b ( 𝜑𝐵𝐼 )
12 0ex ∅ ∈ V
13 12 prid1 ∅ ∈ { ∅ , 1o }
14 df2o3 2o = { ∅ , 1o }
15 13 14 eleqtrri ∅ ∈ 2o
16 opelxpi ( ( 𝐴𝐼 ∧ ∅ ∈ 2o ) → ⟨ 𝐴 , ∅ ⟩ ∈ ( 𝐼 × 2o ) )
17 10 15 16 sylancl ( 𝜑 → ⟨ 𝐴 , ∅ ⟩ ∈ ( 𝐼 × 2o ) )
18 opelxpi ( ( 𝐵𝐼 ∧ ∅ ∈ 2o ) → ⟨ 𝐵 , ∅ ⟩ ∈ ( 𝐼 × 2o ) )
19 11 15 18 sylancl ( 𝜑 → ⟨ 𝐵 , ∅ ⟩ ∈ ( 𝐼 × 2o ) )
20 17 19 s2cld ( 𝜑 → ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ ∈ Word ( 𝐼 × 2o ) )
21 2on 2o ∈ On
22 xpexg ( ( 𝐼𝑉 ∧ 2o ∈ On ) → ( 𝐼 × 2o ) ∈ V )
23 9 21 22 sylancl ( 𝜑 → ( 𝐼 × 2o ) ∈ V )
24 wrdexg ( ( 𝐼 × 2o ) ∈ V → Word ( 𝐼 × 2o ) ∈ V )
25 fvi ( Word ( 𝐼 × 2o ) ∈ V → ( I ‘ Word ( 𝐼 × 2o ) ) = Word ( 𝐼 × 2o ) )
26 23 24 25 3syl ( 𝜑 → ( I ‘ Word ( 𝐼 × 2o ) ) = Word ( 𝐼 × 2o ) )
27 2 26 syl5eq ( 𝜑𝑊 = Word ( 𝐼 × 2o ) )
28 20 27 eleqtrrd ( 𝜑 → ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ ∈ 𝑊 )
29 1n0 1o ≠ ∅
30 2cn 2 ∈ ℂ
31 30 addid2i ( 0 + 2 ) = 2
32 s2len ( ♯ ‘ ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ ) = 2
33 31 32 eqtr4i ( 0 + 2 ) = ( ♯ ‘ ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ )
34 2 3 5 6 efgtlen ( ( 𝑥𝑊 ∧ ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ ∈ ran ( 𝑇𝑥 ) ) → ( ♯ ‘ ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ ) = ( ( ♯ ‘ 𝑥 ) + 2 ) )
35 34 adantll ( ( ( 𝜑𝑥𝑊 ) ∧ ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ ∈ ran ( 𝑇𝑥 ) ) → ( ♯ ‘ ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ ) = ( ( ♯ ‘ 𝑥 ) + 2 ) )
36 33 35 syl5eq ( ( ( 𝜑𝑥𝑊 ) ∧ ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ ∈ ran ( 𝑇𝑥 ) ) → ( 0 + 2 ) = ( ( ♯ ‘ 𝑥 ) + 2 ) )
37 36 ex ( ( 𝜑𝑥𝑊 ) → ( ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ ∈ ran ( 𝑇𝑥 ) → ( 0 + 2 ) = ( ( ♯ ‘ 𝑥 ) + 2 ) ) )
38 0cnd ( ( 𝜑𝑥𝑊 ) → 0 ∈ ℂ )
39 simpr ( ( 𝜑𝑥𝑊 ) → 𝑥𝑊 )
40 2 efgrcl ( 𝑥𝑊 → ( 𝐼 ∈ V ∧ 𝑊 = Word ( 𝐼 × 2o ) ) )
41 40 simprd ( 𝑥𝑊𝑊 = Word ( 𝐼 × 2o ) )
42 41 adantl ( ( 𝜑𝑥𝑊 ) → 𝑊 = Word ( 𝐼 × 2o ) )
43 39 42 eleqtrd ( ( 𝜑𝑥𝑊 ) → 𝑥 ∈ Word ( 𝐼 × 2o ) )
44 lencl ( 𝑥 ∈ Word ( 𝐼 × 2o ) → ( ♯ ‘ 𝑥 ) ∈ ℕ0 )
45 43 44 syl ( ( 𝜑𝑥𝑊 ) → ( ♯ ‘ 𝑥 ) ∈ ℕ0 )
46 45 nn0cnd ( ( 𝜑𝑥𝑊 ) → ( ♯ ‘ 𝑥 ) ∈ ℂ )
47 2cnd ( ( 𝜑𝑥𝑊 ) → 2 ∈ ℂ )
48 38 46 47 addcan2d ( ( 𝜑𝑥𝑊 ) → ( ( 0 + 2 ) = ( ( ♯ ‘ 𝑥 ) + 2 ) ↔ 0 = ( ♯ ‘ 𝑥 ) ) )
49 37 48 sylibd ( ( 𝜑𝑥𝑊 ) → ( ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ ∈ ran ( 𝑇𝑥 ) → 0 = ( ♯ ‘ 𝑥 ) ) )
50 2 3 5 6 efgtf ( ∅ ∈ 𝑊 → ( ( 𝑇 ‘ ∅ ) = ( 𝑎 ∈ ( 0 ... ( ♯ ‘ ∅ ) ) , 𝑏 ∈ ( 𝐼 × 2o ) ↦ ( ∅ splice ⟨ 𝑎 , 𝑎 , ⟨“ 𝑏 ( 𝑀𝑏 ) ”⟩ ⟩ ) ) ∧ ( 𝑇 ‘ ∅ ) : ( ( 0 ... ( ♯ ‘ ∅ ) ) × ( 𝐼 × 2o ) ) ⟶ 𝑊 ) )
51 50 adantl ( ( 𝜑 ∧ ∅ ∈ 𝑊 ) → ( ( 𝑇 ‘ ∅ ) = ( 𝑎 ∈ ( 0 ... ( ♯ ‘ ∅ ) ) , 𝑏 ∈ ( 𝐼 × 2o ) ↦ ( ∅ splice ⟨ 𝑎 , 𝑎 , ⟨“ 𝑏 ( 𝑀𝑏 ) ”⟩ ⟩ ) ) ∧ ( 𝑇 ‘ ∅ ) : ( ( 0 ... ( ♯ ‘ ∅ ) ) × ( 𝐼 × 2o ) ) ⟶ 𝑊 ) )
52 51 simpld ( ( 𝜑 ∧ ∅ ∈ 𝑊 ) → ( 𝑇 ‘ ∅ ) = ( 𝑎 ∈ ( 0 ... ( ♯ ‘ ∅ ) ) , 𝑏 ∈ ( 𝐼 × 2o ) ↦ ( ∅ splice ⟨ 𝑎 , 𝑎 , ⟨“ 𝑏 ( 𝑀𝑏 ) ”⟩ ⟩ ) ) )
53 52 rneqd ( ( 𝜑 ∧ ∅ ∈ 𝑊 ) → ran ( 𝑇 ‘ ∅ ) = ran ( 𝑎 ∈ ( 0 ... ( ♯ ‘ ∅ ) ) , 𝑏 ∈ ( 𝐼 × 2o ) ↦ ( ∅ splice ⟨ 𝑎 , 𝑎 , ⟨“ 𝑏 ( 𝑀𝑏 ) ”⟩ ⟩ ) ) )
54 53 eleq2d ( ( 𝜑 ∧ ∅ ∈ 𝑊 ) → ( ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ ∈ ran ( 𝑇 ‘ ∅ ) ↔ ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ ∈ ran ( 𝑎 ∈ ( 0 ... ( ♯ ‘ ∅ ) ) , 𝑏 ∈ ( 𝐼 × 2o ) ↦ ( ∅ splice ⟨ 𝑎 , 𝑎 , ⟨“ 𝑏 ( 𝑀𝑏 ) ”⟩ ⟩ ) ) ) )
55 eqid ( 𝑎 ∈ ( 0 ... ( ♯ ‘ ∅ ) ) , 𝑏 ∈ ( 𝐼 × 2o ) ↦ ( ∅ splice ⟨ 𝑎 , 𝑎 , ⟨“ 𝑏 ( 𝑀𝑏 ) ”⟩ ⟩ ) ) = ( 𝑎 ∈ ( 0 ... ( ♯ ‘ ∅ ) ) , 𝑏 ∈ ( 𝐼 × 2o ) ↦ ( ∅ splice ⟨ 𝑎 , 𝑎 , ⟨“ 𝑏 ( 𝑀𝑏 ) ”⟩ ⟩ ) )
56 ovex ( ∅ splice ⟨ 𝑎 , 𝑎 , ⟨“ 𝑏 ( 𝑀𝑏 ) ”⟩ ⟩ ) ∈ V
57 55 56 elrnmpo ( ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ ∈ ran ( 𝑎 ∈ ( 0 ... ( ♯ ‘ ∅ ) ) , 𝑏 ∈ ( 𝐼 × 2o ) ↦ ( ∅ splice ⟨ 𝑎 , 𝑎 , ⟨“ 𝑏 ( 𝑀𝑏 ) ”⟩ ⟩ ) ) ↔ ∃ 𝑎 ∈ ( 0 ... ( ♯ ‘ ∅ ) ) ∃ 𝑏 ∈ ( 𝐼 × 2o ) ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ = ( ∅ splice ⟨ 𝑎 , 𝑎 , ⟨“ 𝑏 ( 𝑀𝑏 ) ”⟩ ⟩ ) )
58 wrd0 ∅ ∈ Word ( 𝐼 × 2o )
59 58 a1i ( ( ( 𝜑 ∧ ∅ ∈ 𝑊 ) ∧ ( 𝑎 ∈ ( 0 ... ( ♯ ‘ ∅ ) ) ∧ 𝑏 ∈ ( 𝐼 × 2o ) ) ) → ∅ ∈ Word ( 𝐼 × 2o ) )
60 simprr ( ( ( 𝜑 ∧ ∅ ∈ 𝑊 ) ∧ ( 𝑎 ∈ ( 0 ... ( ♯ ‘ ∅ ) ) ∧ 𝑏 ∈ ( 𝐼 × 2o ) ) ) → 𝑏 ∈ ( 𝐼 × 2o ) )
61 5 efgmf 𝑀 : ( 𝐼 × 2o ) ⟶ ( 𝐼 × 2o )
62 61 ffvelrni ( 𝑏 ∈ ( 𝐼 × 2o ) → ( 𝑀𝑏 ) ∈ ( 𝐼 × 2o ) )
63 60 62 syl ( ( ( 𝜑 ∧ ∅ ∈ 𝑊 ) ∧ ( 𝑎 ∈ ( 0 ... ( ♯ ‘ ∅ ) ) ∧ 𝑏 ∈ ( 𝐼 × 2o ) ) ) → ( 𝑀𝑏 ) ∈ ( 𝐼 × 2o ) )
64 60 63 s2cld ( ( ( 𝜑 ∧ ∅ ∈ 𝑊 ) ∧ ( 𝑎 ∈ ( 0 ... ( ♯ ‘ ∅ ) ) ∧ 𝑏 ∈ ( 𝐼 × 2o ) ) ) → ⟨“ 𝑏 ( 𝑀𝑏 ) ”⟩ ∈ Word ( 𝐼 × 2o ) )
65 ccatidid ( ∅ ++ ∅ ) = ∅
66 65 oveq1i ( ( ∅ ++ ∅ ) ++ ∅ ) = ( ∅ ++ ∅ )
67 66 65 eqtr2i ∅ = ( ( ∅ ++ ∅ ) ++ ∅ )
68 67 a1i ( ( ( 𝜑 ∧ ∅ ∈ 𝑊 ) ∧ ( 𝑎 ∈ ( 0 ... ( ♯ ‘ ∅ ) ) ∧ 𝑏 ∈ ( 𝐼 × 2o ) ) ) → ∅ = ( ( ∅ ++ ∅ ) ++ ∅ ) )
69 simprl ( ( ( 𝜑 ∧ ∅ ∈ 𝑊 ) ∧ ( 𝑎 ∈ ( 0 ... ( ♯ ‘ ∅ ) ) ∧ 𝑏 ∈ ( 𝐼 × 2o ) ) ) → 𝑎 ∈ ( 0 ... ( ♯ ‘ ∅ ) ) )
70 hash0 ( ♯ ‘ ∅ ) = 0
71 70 oveq2i ( 0 ... ( ♯ ‘ ∅ ) ) = ( 0 ... 0 )
72 69 71 eleqtrdi ( ( ( 𝜑 ∧ ∅ ∈ 𝑊 ) ∧ ( 𝑎 ∈ ( 0 ... ( ♯ ‘ ∅ ) ) ∧ 𝑏 ∈ ( 𝐼 × 2o ) ) ) → 𝑎 ∈ ( 0 ... 0 ) )
73 elfz1eq ( 𝑎 ∈ ( 0 ... 0 ) → 𝑎 = 0 )
74 72 73 syl ( ( ( 𝜑 ∧ ∅ ∈ 𝑊 ) ∧ ( 𝑎 ∈ ( 0 ... ( ♯ ‘ ∅ ) ) ∧ 𝑏 ∈ ( 𝐼 × 2o ) ) ) → 𝑎 = 0 )
75 74 70 eqtr4di ( ( ( 𝜑 ∧ ∅ ∈ 𝑊 ) ∧ ( 𝑎 ∈ ( 0 ... ( ♯ ‘ ∅ ) ) ∧ 𝑏 ∈ ( 𝐼 × 2o ) ) ) → 𝑎 = ( ♯ ‘ ∅ ) )
76 70 oveq2i ( 𝑎 + ( ♯ ‘ ∅ ) ) = ( 𝑎 + 0 )
77 0cn 0 ∈ ℂ
78 74 77 eqeltrdi ( ( ( 𝜑 ∧ ∅ ∈ 𝑊 ) ∧ ( 𝑎 ∈ ( 0 ... ( ♯ ‘ ∅ ) ) ∧ 𝑏 ∈ ( 𝐼 × 2o ) ) ) → 𝑎 ∈ ℂ )
79 78 addid1d ( ( ( 𝜑 ∧ ∅ ∈ 𝑊 ) ∧ ( 𝑎 ∈ ( 0 ... ( ♯ ‘ ∅ ) ) ∧ 𝑏 ∈ ( 𝐼 × 2o ) ) ) → ( 𝑎 + 0 ) = 𝑎 )
80 76 79 syl5req ( ( ( 𝜑 ∧ ∅ ∈ 𝑊 ) ∧ ( 𝑎 ∈ ( 0 ... ( ♯ ‘ ∅ ) ) ∧ 𝑏 ∈ ( 𝐼 × 2o ) ) ) → 𝑎 = ( 𝑎 + ( ♯ ‘ ∅ ) ) )
81 59 59 59 64 68 75 80 splval2 ( ( ( 𝜑 ∧ ∅ ∈ 𝑊 ) ∧ ( 𝑎 ∈ ( 0 ... ( ♯ ‘ ∅ ) ) ∧ 𝑏 ∈ ( 𝐼 × 2o ) ) ) → ( ∅ splice ⟨ 𝑎 , 𝑎 , ⟨“ 𝑏 ( 𝑀𝑏 ) ”⟩ ⟩ ) = ( ( ∅ ++ ⟨“ 𝑏 ( 𝑀𝑏 ) ”⟩ ) ++ ∅ ) )
82 ccatlid ( ⟨“ 𝑏 ( 𝑀𝑏 ) ”⟩ ∈ Word ( 𝐼 × 2o ) → ( ∅ ++ ⟨“ 𝑏 ( 𝑀𝑏 ) ”⟩ ) = ⟨“ 𝑏 ( 𝑀𝑏 ) ”⟩ )
83 82 oveq1d ( ⟨“ 𝑏 ( 𝑀𝑏 ) ”⟩ ∈ Word ( 𝐼 × 2o ) → ( ( ∅ ++ ⟨“ 𝑏 ( 𝑀𝑏 ) ”⟩ ) ++ ∅ ) = ( ⟨“ 𝑏 ( 𝑀𝑏 ) ”⟩ ++ ∅ ) )
84 ccatrid ( ⟨“ 𝑏 ( 𝑀𝑏 ) ”⟩ ∈ Word ( 𝐼 × 2o ) → ( ⟨“ 𝑏 ( 𝑀𝑏 ) ”⟩ ++ ∅ ) = ⟨“ 𝑏 ( 𝑀𝑏 ) ”⟩ )
85 83 84 eqtrd ( ⟨“ 𝑏 ( 𝑀𝑏 ) ”⟩ ∈ Word ( 𝐼 × 2o ) → ( ( ∅ ++ ⟨“ 𝑏 ( 𝑀𝑏 ) ”⟩ ) ++ ∅ ) = ⟨“ 𝑏 ( 𝑀𝑏 ) ”⟩ )
86 64 85 syl ( ( ( 𝜑 ∧ ∅ ∈ 𝑊 ) ∧ ( 𝑎 ∈ ( 0 ... ( ♯ ‘ ∅ ) ) ∧ 𝑏 ∈ ( 𝐼 × 2o ) ) ) → ( ( ∅ ++ ⟨“ 𝑏 ( 𝑀𝑏 ) ”⟩ ) ++ ∅ ) = ⟨“ 𝑏 ( 𝑀𝑏 ) ”⟩ )
87 81 86 eqtrd ( ( ( 𝜑 ∧ ∅ ∈ 𝑊 ) ∧ ( 𝑎 ∈ ( 0 ... ( ♯ ‘ ∅ ) ) ∧ 𝑏 ∈ ( 𝐼 × 2o ) ) ) → ( ∅ splice ⟨ 𝑎 , 𝑎 , ⟨“ 𝑏 ( 𝑀𝑏 ) ”⟩ ⟩ ) = ⟨“ 𝑏 ( 𝑀𝑏 ) ”⟩ )
88 87 eqeq2d ( ( ( 𝜑 ∧ ∅ ∈ 𝑊 ) ∧ ( 𝑎 ∈ ( 0 ... ( ♯ ‘ ∅ ) ) ∧ 𝑏 ∈ ( 𝐼 × 2o ) ) ) → ( ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ = ( ∅ splice ⟨ 𝑎 , 𝑎 , ⟨“ 𝑏 ( 𝑀𝑏 ) ”⟩ ⟩ ) ↔ ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ = ⟨“ 𝑏 ( 𝑀𝑏 ) ”⟩ ) )
89 10 ad3antrrr ( ( ( ( 𝜑 ∧ ∅ ∈ 𝑊 ) ∧ ( 𝑎 ∈ ( 0 ... ( ♯ ‘ ∅ ) ) ∧ 𝑏 ∈ ( 𝐼 × 2o ) ) ) ∧ ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ = ⟨“ 𝑏 ( 𝑀𝑏 ) ”⟩ ) → 𝐴𝐼 )
90 1on 1o ∈ On
91 90 a1i ( ( ( ( 𝜑 ∧ ∅ ∈ 𝑊 ) ∧ ( 𝑎 ∈ ( 0 ... ( ♯ ‘ ∅ ) ) ∧ 𝑏 ∈ ( 𝐼 × 2o ) ) ) ∧ ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ = ⟨“ 𝑏 ( 𝑀𝑏 ) ”⟩ ) → 1o ∈ On )
92 simpr ( ( ( ( 𝜑 ∧ ∅ ∈ 𝑊 ) ∧ ( 𝑎 ∈ ( 0 ... ( ♯ ‘ ∅ ) ) ∧ 𝑏 ∈ ( 𝐼 × 2o ) ) ) ∧ ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ = ⟨“ 𝑏 ( 𝑀𝑏 ) ”⟩ ) → ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ = ⟨“ 𝑏 ( 𝑀𝑏 ) ”⟩ )
93 92 fveq1d ( ( ( ( 𝜑 ∧ ∅ ∈ 𝑊 ) ∧ ( 𝑎 ∈ ( 0 ... ( ♯ ‘ ∅ ) ) ∧ 𝑏 ∈ ( 𝐼 × 2o ) ) ) ∧ ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ = ⟨“ 𝑏 ( 𝑀𝑏 ) ”⟩ ) → ( ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ ‘ 1 ) = ( ⟨“ 𝑏 ( 𝑀𝑏 ) ”⟩ ‘ 1 ) )
94 opex 𝐵 , ∅ ⟩ ∈ V
95 s2fv1 ( ⟨ 𝐵 , ∅ ⟩ ∈ V → ( ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ ‘ 1 ) = ⟨ 𝐵 , ∅ ⟩ )
96 94 95 ax-mp ( ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ ‘ 1 ) = ⟨ 𝐵 , ∅ ⟩
97 fvex ( 𝑀𝑏 ) ∈ V
98 s2fv1 ( ( 𝑀𝑏 ) ∈ V → ( ⟨“ 𝑏 ( 𝑀𝑏 ) ”⟩ ‘ 1 ) = ( 𝑀𝑏 ) )
99 97 98 ax-mp ( ⟨“ 𝑏 ( 𝑀𝑏 ) ”⟩ ‘ 1 ) = ( 𝑀𝑏 )
100 93 96 99 3eqtr3g ( ( ( ( 𝜑 ∧ ∅ ∈ 𝑊 ) ∧ ( 𝑎 ∈ ( 0 ... ( ♯ ‘ ∅ ) ) ∧ 𝑏 ∈ ( 𝐼 × 2o ) ) ) ∧ ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ = ⟨“ 𝑏 ( 𝑀𝑏 ) ”⟩ ) → ⟨ 𝐵 , ∅ ⟩ = ( 𝑀𝑏 ) )
101 92 fveq1d ( ( ( ( 𝜑 ∧ ∅ ∈ 𝑊 ) ∧ ( 𝑎 ∈ ( 0 ... ( ♯ ‘ ∅ ) ) ∧ 𝑏 ∈ ( 𝐼 × 2o ) ) ) ∧ ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ = ⟨“ 𝑏 ( 𝑀𝑏 ) ”⟩ ) → ( ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ ‘ 0 ) = ( ⟨“ 𝑏 ( 𝑀𝑏 ) ”⟩ ‘ 0 ) )
102 opex 𝐴 , ∅ ⟩ ∈ V
103 s2fv0 ( ⟨ 𝐴 , ∅ ⟩ ∈ V → ( ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ ‘ 0 ) = ⟨ 𝐴 , ∅ ⟩ )
104 102 103 ax-mp ( ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ ‘ 0 ) = ⟨ 𝐴 , ∅ ⟩
105 s2fv0 ( 𝑏 ∈ V → ( ⟨“ 𝑏 ( 𝑀𝑏 ) ”⟩ ‘ 0 ) = 𝑏 )
106 105 elv ( ⟨“ 𝑏 ( 𝑀𝑏 ) ”⟩ ‘ 0 ) = 𝑏
107 101 104 106 3eqtr3g ( ( ( ( 𝜑 ∧ ∅ ∈ 𝑊 ) ∧ ( 𝑎 ∈ ( 0 ... ( ♯ ‘ ∅ ) ) ∧ 𝑏 ∈ ( 𝐼 × 2o ) ) ) ∧ ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ = ⟨“ 𝑏 ( 𝑀𝑏 ) ”⟩ ) → ⟨ 𝐴 , ∅ ⟩ = 𝑏 )
108 107 fveq2d ( ( ( ( 𝜑 ∧ ∅ ∈ 𝑊 ) ∧ ( 𝑎 ∈ ( 0 ... ( ♯ ‘ ∅ ) ) ∧ 𝑏 ∈ ( 𝐼 × 2o ) ) ) ∧ ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ = ⟨“ 𝑏 ( 𝑀𝑏 ) ”⟩ ) → ( 𝑀 ‘ ⟨ 𝐴 , ∅ ⟩ ) = ( 𝑀𝑏 ) )
109 5 efgmval ( ( 𝐴𝐼 ∧ ∅ ∈ 2o ) → ( 𝐴 𝑀 ∅ ) = ⟨ 𝐴 , ( 1o ∖ ∅ ) ⟩ )
110 89 15 109 sylancl ( ( ( ( 𝜑 ∧ ∅ ∈ 𝑊 ) ∧ ( 𝑎 ∈ ( 0 ... ( ♯ ‘ ∅ ) ) ∧ 𝑏 ∈ ( 𝐼 × 2o ) ) ) ∧ ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ = ⟨“ 𝑏 ( 𝑀𝑏 ) ”⟩ ) → ( 𝐴 𝑀 ∅ ) = ⟨ 𝐴 , ( 1o ∖ ∅ ) ⟩ )
111 df-ov ( 𝐴 𝑀 ∅ ) = ( 𝑀 ‘ ⟨ 𝐴 , ∅ ⟩ )
112 dif0 ( 1o ∖ ∅ ) = 1o
113 112 opeq2i 𝐴 , ( 1o ∖ ∅ ) ⟩ = ⟨ 𝐴 , 1o
114 110 111 113 3eqtr3g ( ( ( ( 𝜑 ∧ ∅ ∈ 𝑊 ) ∧ ( 𝑎 ∈ ( 0 ... ( ♯ ‘ ∅ ) ) ∧ 𝑏 ∈ ( 𝐼 × 2o ) ) ) ∧ ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ = ⟨“ 𝑏 ( 𝑀𝑏 ) ”⟩ ) → ( 𝑀 ‘ ⟨ 𝐴 , ∅ ⟩ ) = ⟨ 𝐴 , 1o ⟩ )
115 100 108 114 3eqtr2rd ( ( ( ( 𝜑 ∧ ∅ ∈ 𝑊 ) ∧ ( 𝑎 ∈ ( 0 ... ( ♯ ‘ ∅ ) ) ∧ 𝑏 ∈ ( 𝐼 × 2o ) ) ) ∧ ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ = ⟨“ 𝑏 ( 𝑀𝑏 ) ”⟩ ) → ⟨ 𝐴 , 1o ⟩ = ⟨ 𝐵 , ∅ ⟩ )
116 opthg ( ( 𝐴𝐼 ∧ 1o ∈ On ) → ( ⟨ 𝐴 , 1o ⟩ = ⟨ 𝐵 , ∅ ⟩ ↔ ( 𝐴 = 𝐵 ∧ 1o = ∅ ) ) )
117 116 simplbda ( ( ( 𝐴𝐼 ∧ 1o ∈ On ) ∧ ⟨ 𝐴 , 1o ⟩ = ⟨ 𝐵 , ∅ ⟩ ) → 1o = ∅ )
118 89 91 115 117 syl21anc ( ( ( ( 𝜑 ∧ ∅ ∈ 𝑊 ) ∧ ( 𝑎 ∈ ( 0 ... ( ♯ ‘ ∅ ) ) ∧ 𝑏 ∈ ( 𝐼 × 2o ) ) ) ∧ ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ = ⟨“ 𝑏 ( 𝑀𝑏 ) ”⟩ ) → 1o = ∅ )
119 118 ex ( ( ( 𝜑 ∧ ∅ ∈ 𝑊 ) ∧ ( 𝑎 ∈ ( 0 ... ( ♯ ‘ ∅ ) ) ∧ 𝑏 ∈ ( 𝐼 × 2o ) ) ) → ( ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ = ⟨“ 𝑏 ( 𝑀𝑏 ) ”⟩ → 1o = ∅ ) )
120 88 119 sylbid ( ( ( 𝜑 ∧ ∅ ∈ 𝑊 ) ∧ ( 𝑎 ∈ ( 0 ... ( ♯ ‘ ∅ ) ) ∧ 𝑏 ∈ ( 𝐼 × 2o ) ) ) → ( ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ = ( ∅ splice ⟨ 𝑎 , 𝑎 , ⟨“ 𝑏 ( 𝑀𝑏 ) ”⟩ ⟩ ) → 1o = ∅ ) )
121 120 rexlimdvva ( ( 𝜑 ∧ ∅ ∈ 𝑊 ) → ( ∃ 𝑎 ∈ ( 0 ... ( ♯ ‘ ∅ ) ) ∃ 𝑏 ∈ ( 𝐼 × 2o ) ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ = ( ∅ splice ⟨ 𝑎 , 𝑎 , ⟨“ 𝑏 ( 𝑀𝑏 ) ”⟩ ⟩ ) → 1o = ∅ ) )
122 57 121 syl5bi ( ( 𝜑 ∧ ∅ ∈ 𝑊 ) → ( ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ ∈ ran ( 𝑎 ∈ ( 0 ... ( ♯ ‘ ∅ ) ) , 𝑏 ∈ ( 𝐼 × 2o ) ↦ ( ∅ splice ⟨ 𝑎 , 𝑎 , ⟨“ 𝑏 ( 𝑀𝑏 ) ”⟩ ⟩ ) ) → 1o = ∅ ) )
123 54 122 sylbid ( ( 𝜑 ∧ ∅ ∈ 𝑊 ) → ( ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ ∈ ran ( 𝑇 ‘ ∅ ) → 1o = ∅ ) )
124 123 expimpd ( 𝜑 → ( ( ∅ ∈ 𝑊 ∧ ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ ∈ ran ( 𝑇 ‘ ∅ ) ) → 1o = ∅ ) )
125 hasheq0 ( 𝑥 ∈ V → ( ( ♯ ‘ 𝑥 ) = 0 ↔ 𝑥 = ∅ ) )
126 125 elv ( ( ♯ ‘ 𝑥 ) = 0 ↔ 𝑥 = ∅ )
127 eleq1 ( 𝑥 = ∅ → ( 𝑥𝑊 ↔ ∅ ∈ 𝑊 ) )
128 fveq2 ( 𝑥 = ∅ → ( 𝑇𝑥 ) = ( 𝑇 ‘ ∅ ) )
129 128 rneqd ( 𝑥 = ∅ → ran ( 𝑇𝑥 ) = ran ( 𝑇 ‘ ∅ ) )
130 129 eleq2d ( 𝑥 = ∅ → ( ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ ∈ ran ( 𝑇𝑥 ) ↔ ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ ∈ ran ( 𝑇 ‘ ∅ ) ) )
131 127 130 anbi12d ( 𝑥 = ∅ → ( ( 𝑥𝑊 ∧ ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ ∈ ran ( 𝑇𝑥 ) ) ↔ ( ∅ ∈ 𝑊 ∧ ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ ∈ ran ( 𝑇 ‘ ∅ ) ) ) )
132 126 131 sylbi ( ( ♯ ‘ 𝑥 ) = 0 → ( ( 𝑥𝑊 ∧ ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ ∈ ran ( 𝑇𝑥 ) ) ↔ ( ∅ ∈ 𝑊 ∧ ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ ∈ ran ( 𝑇 ‘ ∅ ) ) ) )
133 132 eqcoms ( 0 = ( ♯ ‘ 𝑥 ) → ( ( 𝑥𝑊 ∧ ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ ∈ ran ( 𝑇𝑥 ) ) ↔ ( ∅ ∈ 𝑊 ∧ ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ ∈ ran ( 𝑇 ‘ ∅ ) ) ) )
134 133 imbi1d ( 0 = ( ♯ ‘ 𝑥 ) → ( ( ( 𝑥𝑊 ∧ ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ ∈ ran ( 𝑇𝑥 ) ) → 1o = ∅ ) ↔ ( ( ∅ ∈ 𝑊 ∧ ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ ∈ ran ( 𝑇 ‘ ∅ ) ) → 1o = ∅ ) ) )
135 124 134 syl5ibrcom ( 𝜑 → ( 0 = ( ♯ ‘ 𝑥 ) → ( ( 𝑥𝑊 ∧ ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ ∈ ran ( 𝑇𝑥 ) ) → 1o = ∅ ) ) )
136 135 com23 ( 𝜑 → ( ( 𝑥𝑊 ∧ ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ ∈ ran ( 𝑇𝑥 ) ) → ( 0 = ( ♯ ‘ 𝑥 ) → 1o = ∅ ) ) )
137 136 expdimp ( ( 𝜑𝑥𝑊 ) → ( ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ ∈ ran ( 𝑇𝑥 ) → ( 0 = ( ♯ ‘ 𝑥 ) → 1o = ∅ ) ) )
138 49 137 mpdd ( ( 𝜑𝑥𝑊 ) → ( ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ ∈ ran ( 𝑇𝑥 ) → 1o = ∅ ) )
139 138 necon3ad ( ( 𝜑𝑥𝑊 ) → ( 1o ≠ ∅ → ¬ ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ ∈ ran ( 𝑇𝑥 ) ) )
140 29 139 mpi ( ( 𝜑𝑥𝑊 ) → ¬ ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ ∈ ran ( 𝑇𝑥 ) )
141 140 nrexdv ( 𝜑 → ¬ ∃ 𝑥𝑊 ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ ∈ ran ( 𝑇𝑥 ) )
142 eliun ( ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ ∈ 𝑥𝑊 ran ( 𝑇𝑥 ) ↔ ∃ 𝑥𝑊 ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ ∈ ran ( 𝑇𝑥 ) )
143 141 142 sylnibr ( 𝜑 → ¬ ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ ∈ 𝑥𝑊 ran ( 𝑇𝑥 ) )
144 28 143 eldifd ( 𝜑 → ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ ∈ ( 𝑊 𝑥𝑊 ran ( 𝑇𝑥 ) ) )
145 144 7 eleqtrrdi ( 𝜑 → ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ ∈ 𝐷 )
146 df-s2 ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ = ( ⟨“ ⟨ 𝐴 , ∅ ⟩ ”⟩ ++ ⟨“ ⟨ 𝐵 , ∅ ⟩ ”⟩ )
147 2 3 efger Er 𝑊
148 147 a1i ( 𝜑 Er 𝑊 )
149 148 28 erref ( 𝜑 → ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ )
150 146 149 eqbrtrrid ( 𝜑 → ( ⟨“ ⟨ 𝐴 , ∅ ⟩ ”⟩ ++ ⟨“ ⟨ 𝐵 , ∅ ⟩ ”⟩ ) ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ )
151 146 ovexi ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ ∈ V
152 ovex ( ⟨“ ⟨ 𝐴 , ∅ ⟩ ”⟩ ++ ⟨“ ⟨ 𝐵 , ∅ ⟩ ”⟩ ) ∈ V
153 151 152 elec ( ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ ∈ [ ( ⟨“ ⟨ 𝐴 , ∅ ⟩ ”⟩ ++ ⟨“ ⟨ 𝐵 , ∅ ⟩ ”⟩ ) ] ↔ ( ⟨“ ⟨ 𝐴 , ∅ ⟩ ”⟩ ++ ⟨“ ⟨ 𝐵 , ∅ ⟩ ”⟩ ) ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ )
154 150 153 sylibr ( 𝜑 → ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ ∈ [ ( ⟨“ ⟨ 𝐴 , ∅ ⟩ ”⟩ ++ ⟨“ ⟨ 𝐵 , ∅ ⟩ ”⟩ ) ] )
155 3 8 vrgpval ( ( 𝐼𝑉𝐴𝐼 ) → ( 𝑈𝐴 ) = [ ⟨“ ⟨ 𝐴 , ∅ ⟩ ”⟩ ] )
156 9 10 155 syl2anc ( 𝜑 → ( 𝑈𝐴 ) = [ ⟨“ ⟨ 𝐴 , ∅ ⟩ ”⟩ ] )
157 3 8 vrgpval ( ( 𝐼𝑉𝐵𝐼 ) → ( 𝑈𝐵 ) = [ ⟨“ ⟨ 𝐵 , ∅ ⟩ ”⟩ ] )
158 9 11 157 syl2anc ( 𝜑 → ( 𝑈𝐵 ) = [ ⟨“ ⟨ 𝐵 , ∅ ⟩ ”⟩ ] )
159 156 158 oveq12d ( 𝜑 → ( ( 𝑈𝐴 ) + ( 𝑈𝐵 ) ) = ( [ ⟨“ ⟨ 𝐴 , ∅ ⟩ ”⟩ ] + [ ⟨“ ⟨ 𝐵 , ∅ ⟩ ”⟩ ] ) )
160 17 s1cld ( 𝜑 → ⟨“ ⟨ 𝐴 , ∅ ⟩ ”⟩ ∈ Word ( 𝐼 × 2o ) )
161 160 27 eleqtrrd ( 𝜑 → ⟨“ ⟨ 𝐴 , ∅ ⟩ ”⟩ ∈ 𝑊 )
162 19 s1cld ( 𝜑 → ⟨“ ⟨ 𝐵 , ∅ ⟩ ”⟩ ∈ Word ( 𝐼 × 2o ) )
163 162 27 eleqtrrd ( 𝜑 → ⟨“ ⟨ 𝐵 , ∅ ⟩ ”⟩ ∈ 𝑊 )
164 2 1 3 4 frgpadd ( ( ⟨“ ⟨ 𝐴 , ∅ ⟩ ”⟩ ∈ 𝑊 ∧ ⟨“ ⟨ 𝐵 , ∅ ⟩ ”⟩ ∈ 𝑊 ) → ( [ ⟨“ ⟨ 𝐴 , ∅ ⟩ ”⟩ ] + [ ⟨“ ⟨ 𝐵 , ∅ ⟩ ”⟩ ] ) = [ ( ⟨“ ⟨ 𝐴 , ∅ ⟩ ”⟩ ++ ⟨“ ⟨ 𝐵 , ∅ ⟩ ”⟩ ) ] )
165 161 163 164 syl2anc ( 𝜑 → ( [ ⟨“ ⟨ 𝐴 , ∅ ⟩ ”⟩ ] + [ ⟨“ ⟨ 𝐵 , ∅ ⟩ ”⟩ ] ) = [ ( ⟨“ ⟨ 𝐴 , ∅ ⟩ ”⟩ ++ ⟨“ ⟨ 𝐵 , ∅ ⟩ ”⟩ ) ] )
166 159 165 eqtrd ( 𝜑 → ( ( 𝑈𝐴 ) + ( 𝑈𝐵 ) ) = [ ( ⟨“ ⟨ 𝐴 , ∅ ⟩ ”⟩ ++ ⟨“ ⟨ 𝐵 , ∅ ⟩ ”⟩ ) ] )
167 154 166 eleqtrrd ( 𝜑 → ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ ∈ ( ( 𝑈𝐴 ) + ( 𝑈𝐵 ) ) )
168 145 167 elind ( 𝜑 → ⟨“ ⟨ 𝐴 , ∅ ⟩ ⟨ 𝐵 , ∅ ⟩ ”⟩ ∈ ( 𝐷 ∩ ( ( 𝑈𝐴 ) + ( 𝑈𝐵 ) ) ) )