Metamath Proof Explorer


Theorem isomenndlem

Description: O is sub-additive w.r.t. countable indexed union, implies that O is sub-additive w.r.t. countable union. Thus, the definition of Outer Measure can be given using an indexed union. Definition 113A of Fremlin1 p. 19 . (Contributed by Glauco Siliprandi, 11-Oct-2020)

Ref Expression
Hypotheses isomenndlem.o ( 𝜑𝑂 : 𝒫 𝑋 ⟶ ( 0 [,] +∞ ) )
isomenndlem.o0 ( 𝜑 → ( 𝑂 ‘ ∅ ) = 0 )
isomenndlem.y ( 𝜑𝑌 ⊆ 𝒫 𝑋 )
isomenndlem.subadd ( ( 𝜑𝑎 : ℕ ⟶ 𝒫 𝑋 ) → ( 𝑂 𝑛 ∈ ℕ ( 𝑎𝑛 ) ) ≤ ( Σ^ ‘ ( 𝑛 ∈ ℕ ↦ ( 𝑂 ‘ ( 𝑎𝑛 ) ) ) ) )
isomenndlem.b ( 𝜑𝐵 ⊆ ℕ )
isomenndlem.f ( 𝜑𝐹 : 𝐵1-1-onto𝑌 )
isomenndlem.a 𝐴 = ( 𝑛 ∈ ℕ ↦ if ( 𝑛𝐵 , ( 𝐹𝑛 ) , ∅ ) )
Assertion isomenndlem ( 𝜑 → ( 𝑂 𝑌 ) ≤ ( Σ^ ‘ ( 𝑂𝑌 ) ) )

Proof

Step Hyp Ref Expression
1 isomenndlem.o ( 𝜑𝑂 : 𝒫 𝑋 ⟶ ( 0 [,] +∞ ) )
2 isomenndlem.o0 ( 𝜑 → ( 𝑂 ‘ ∅ ) = 0 )
3 isomenndlem.y ( 𝜑𝑌 ⊆ 𝒫 𝑋 )
4 isomenndlem.subadd ( ( 𝜑𝑎 : ℕ ⟶ 𝒫 𝑋 ) → ( 𝑂 𝑛 ∈ ℕ ( 𝑎𝑛 ) ) ≤ ( Σ^ ‘ ( 𝑛 ∈ ℕ ↦ ( 𝑂 ‘ ( 𝑎𝑛 ) ) ) ) )
5 isomenndlem.b ( 𝜑𝐵 ⊆ ℕ )
6 isomenndlem.f ( 𝜑𝐹 : 𝐵1-1-onto𝑌 )
7 isomenndlem.a 𝐴 = ( 𝑛 ∈ ℕ ↦ if ( 𝑛𝐵 , ( 𝐹𝑛 ) , ∅ ) )
8 id ( 𝜑𝜑 )
9 iftrue ( 𝑛𝐵 → if ( 𝑛𝐵 , ( 𝐹𝑛 ) , ∅ ) = ( 𝐹𝑛 ) )
10 9 adantl ( ( 𝜑𝑛𝐵 ) → if ( 𝑛𝐵 , ( 𝐹𝑛 ) , ∅ ) = ( 𝐹𝑛 ) )
11 f1of ( 𝐹 : 𝐵1-1-onto𝑌𝐹 : 𝐵𝑌 )
12 6 11 syl ( 𝜑𝐹 : 𝐵𝑌 )
13 ssun1 𝑌 ⊆ ( 𝑌 ∪ { ∅ } )
14 13 a1i ( 𝜑𝑌 ⊆ ( 𝑌 ∪ { ∅ } ) )
15 12 14 fssd ( 𝜑𝐹 : 𝐵 ⟶ ( 𝑌 ∪ { ∅ } ) )
16 15 ffvelrnda ( ( 𝜑𝑛𝐵 ) → ( 𝐹𝑛 ) ∈ ( 𝑌 ∪ { ∅ } ) )
17 10 16 eqeltrd ( ( 𝜑𝑛𝐵 ) → if ( 𝑛𝐵 , ( 𝐹𝑛 ) , ∅ ) ∈ ( 𝑌 ∪ { ∅ } ) )
18 17 adantlr ( ( ( 𝜑𝑛 ∈ ℕ ) ∧ 𝑛𝐵 ) → if ( 𝑛𝐵 , ( 𝐹𝑛 ) , ∅ ) ∈ ( 𝑌 ∪ { ∅ } ) )
19 iffalse ( ¬ 𝑛𝐵 → if ( 𝑛𝐵 , ( 𝐹𝑛 ) , ∅ ) = ∅ )
20 19 adantl ( ( 𝜑 ∧ ¬ 𝑛𝐵 ) → if ( 𝑛𝐵 , ( 𝐹𝑛 ) , ∅ ) = ∅ )
21 0ex ∅ ∈ V
22 21 snid ∅ ∈ { ∅ }
23 elun2 ( ∅ ∈ { ∅ } → ∅ ∈ ( 𝑌 ∪ { ∅ } ) )
24 22 23 ax-mp ∅ ∈ ( 𝑌 ∪ { ∅ } )
25 24 a1i ( ( 𝜑 ∧ ¬ 𝑛𝐵 ) → ∅ ∈ ( 𝑌 ∪ { ∅ } ) )
26 20 25 eqeltrd ( ( 𝜑 ∧ ¬ 𝑛𝐵 ) → if ( 𝑛𝐵 , ( 𝐹𝑛 ) , ∅ ) ∈ ( 𝑌 ∪ { ∅ } ) )
27 26 adantlr ( ( ( 𝜑𝑛 ∈ ℕ ) ∧ ¬ 𝑛𝐵 ) → if ( 𝑛𝐵 , ( 𝐹𝑛 ) , ∅ ) ∈ ( 𝑌 ∪ { ∅ } ) )
28 18 27 pm2.61dan ( ( 𝜑𝑛 ∈ ℕ ) → if ( 𝑛𝐵 , ( 𝐹𝑛 ) , ∅ ) ∈ ( 𝑌 ∪ { ∅ } ) )
29 28 7 fmptd ( 𝜑𝐴 : ℕ ⟶ ( 𝑌 ∪ { ∅ } ) )
30 0elpw ∅ ∈ 𝒫 𝑋
31 snssi ( ∅ ∈ 𝒫 𝑋 → { ∅ } ⊆ 𝒫 𝑋 )
32 30 31 ax-mp { ∅ } ⊆ 𝒫 𝑋
33 32 a1i ( 𝜑 → { ∅ } ⊆ 𝒫 𝑋 )
34 3 33 unssd ( 𝜑 → ( 𝑌 ∪ { ∅ } ) ⊆ 𝒫 𝑋 )
35 29 34 fssd ( 𝜑𝐴 : ℕ ⟶ 𝒫 𝑋 )
36 nnex ℕ ∈ V
37 36 mptex ( 𝑛 ∈ ℕ ↦ if ( 𝑛𝐵 , ( 𝐹𝑛 ) , ∅ ) ) ∈ V
38 7 37 eqeltri 𝐴 ∈ V
39 feq1 ( 𝑎 = 𝐴 → ( 𝑎 : ℕ ⟶ 𝒫 𝑋𝐴 : ℕ ⟶ 𝒫 𝑋 ) )
40 39 anbi2d ( 𝑎 = 𝐴 → ( ( 𝜑𝑎 : ℕ ⟶ 𝒫 𝑋 ) ↔ ( 𝜑𝐴 : ℕ ⟶ 𝒫 𝑋 ) ) )
41 fveq1 ( 𝑎 = 𝐴 → ( 𝑎𝑛 ) = ( 𝐴𝑛 ) )
42 41 iuneq2d ( 𝑎 = 𝐴 𝑛 ∈ ℕ ( 𝑎𝑛 ) = 𝑛 ∈ ℕ ( 𝐴𝑛 ) )
43 42 fveq2d ( 𝑎 = 𝐴 → ( 𝑂 𝑛 ∈ ℕ ( 𝑎𝑛 ) ) = ( 𝑂 𝑛 ∈ ℕ ( 𝐴𝑛 ) ) )
44 simpl ( ( 𝑎 = 𝐴𝑛 ∈ ℕ ) → 𝑎 = 𝐴 )
45 44 fveq1d ( ( 𝑎 = 𝐴𝑛 ∈ ℕ ) → ( 𝑎𝑛 ) = ( 𝐴𝑛 ) )
46 45 fveq2d ( ( 𝑎 = 𝐴𝑛 ∈ ℕ ) → ( 𝑂 ‘ ( 𝑎𝑛 ) ) = ( 𝑂 ‘ ( 𝐴𝑛 ) ) )
47 46 mpteq2dva ( 𝑎 = 𝐴 → ( 𝑛 ∈ ℕ ↦ ( 𝑂 ‘ ( 𝑎𝑛 ) ) ) = ( 𝑛 ∈ ℕ ↦ ( 𝑂 ‘ ( 𝐴𝑛 ) ) ) )
48 47 fveq2d ( 𝑎 = 𝐴 → ( Σ^ ‘ ( 𝑛 ∈ ℕ ↦ ( 𝑂 ‘ ( 𝑎𝑛 ) ) ) ) = ( Σ^ ‘ ( 𝑛 ∈ ℕ ↦ ( 𝑂 ‘ ( 𝐴𝑛 ) ) ) ) )
49 43 48 breq12d ( 𝑎 = 𝐴 → ( ( 𝑂 𝑛 ∈ ℕ ( 𝑎𝑛 ) ) ≤ ( Σ^ ‘ ( 𝑛 ∈ ℕ ↦ ( 𝑂 ‘ ( 𝑎𝑛 ) ) ) ) ↔ ( 𝑂 𝑛 ∈ ℕ ( 𝐴𝑛 ) ) ≤ ( Σ^ ‘ ( 𝑛 ∈ ℕ ↦ ( 𝑂 ‘ ( 𝐴𝑛 ) ) ) ) ) )
50 40 49 imbi12d ( 𝑎 = 𝐴 → ( ( ( 𝜑𝑎 : ℕ ⟶ 𝒫 𝑋 ) → ( 𝑂 𝑛 ∈ ℕ ( 𝑎𝑛 ) ) ≤ ( Σ^ ‘ ( 𝑛 ∈ ℕ ↦ ( 𝑂 ‘ ( 𝑎𝑛 ) ) ) ) ) ↔ ( ( 𝜑𝐴 : ℕ ⟶ 𝒫 𝑋 ) → ( 𝑂 𝑛 ∈ ℕ ( 𝐴𝑛 ) ) ≤ ( Σ^ ‘ ( 𝑛 ∈ ℕ ↦ ( 𝑂 ‘ ( 𝐴𝑛 ) ) ) ) ) ) )
51 38 50 4 vtocl ( ( 𝜑𝐴 : ℕ ⟶ 𝒫 𝑋 ) → ( 𝑂 𝑛 ∈ ℕ ( 𝐴𝑛 ) ) ≤ ( Σ^ ‘ ( 𝑛 ∈ ℕ ↦ ( 𝑂 ‘ ( 𝐴𝑛 ) ) ) ) )
52 8 35 51 syl2anc ( 𝜑 → ( 𝑂 𝑛 ∈ ℕ ( 𝐴𝑛 ) ) ≤ ( Σ^ ‘ ( 𝑛 ∈ ℕ ↦ ( 𝑂 ‘ ( 𝐴𝑛 ) ) ) ) )
53 12 ad2antrr ( ( ( 𝜑𝐵 = ℕ ) ∧ 𝑛 ∈ ℕ ) → 𝐹 : 𝐵𝑌 )
54 simpr ( ( 𝐵 = ℕ ∧ 𝑛 ∈ ℕ ) → 𝑛 ∈ ℕ )
55 id ( 𝐵 = ℕ → 𝐵 = ℕ )
56 55 eqcomd ( 𝐵 = ℕ → ℕ = 𝐵 )
57 56 adantr ( ( 𝐵 = ℕ ∧ 𝑛 ∈ ℕ ) → ℕ = 𝐵 )
58 54 57 eleqtrd ( ( 𝐵 = ℕ ∧ 𝑛 ∈ ℕ ) → 𝑛𝐵 )
59 58 adantll ( ( ( 𝜑𝐵 = ℕ ) ∧ 𝑛 ∈ ℕ ) → 𝑛𝐵 )
60 53 59 ffvelrnd ( ( ( 𝜑𝐵 = ℕ ) ∧ 𝑛 ∈ ℕ ) → ( 𝐹𝑛 ) ∈ 𝑌 )
61 eqid ( 𝑛 ∈ ℕ ↦ ( 𝐹𝑛 ) ) = ( 𝑛 ∈ ℕ ↦ ( 𝐹𝑛 ) )
62 60 61 fmptd ( ( 𝜑𝐵 = ℕ ) → ( 𝑛 ∈ ℕ ↦ ( 𝐹𝑛 ) ) : ℕ ⟶ 𝑌 )
63 7 a1i ( 𝐵 = ℕ → 𝐴 = ( 𝑛 ∈ ℕ ↦ if ( 𝑛𝐵 , ( 𝐹𝑛 ) , ∅ ) ) )
64 58 iftrued ( ( 𝐵 = ℕ ∧ 𝑛 ∈ ℕ ) → if ( 𝑛𝐵 , ( 𝐹𝑛 ) , ∅ ) = ( 𝐹𝑛 ) )
65 64 mpteq2dva ( 𝐵 = ℕ → ( 𝑛 ∈ ℕ ↦ if ( 𝑛𝐵 , ( 𝐹𝑛 ) , ∅ ) ) = ( 𝑛 ∈ ℕ ↦ ( 𝐹𝑛 ) ) )
66 63 65 eqtrd ( 𝐵 = ℕ → 𝐴 = ( 𝑛 ∈ ℕ ↦ ( 𝐹𝑛 ) ) )
67 66 feq1d ( 𝐵 = ℕ → ( 𝐴 : ℕ ⟶ 𝑌 ↔ ( 𝑛 ∈ ℕ ↦ ( 𝐹𝑛 ) ) : ℕ ⟶ 𝑌 ) )
68 67 adantl ( ( 𝜑𝐵 = ℕ ) → ( 𝐴 : ℕ ⟶ 𝑌 ↔ ( 𝑛 ∈ ℕ ↦ ( 𝐹𝑛 ) ) : ℕ ⟶ 𝑌 ) )
69 62 68 mpbird ( ( 𝜑𝐵 = ℕ ) → 𝐴 : ℕ ⟶ 𝑌 )
70 f1ofo ( 𝐹 : 𝐵1-1-onto𝑌𝐹 : 𝐵onto𝑌 )
71 6 70 syl ( 𝜑𝐹 : 𝐵onto𝑌 )
72 dffo3 ( 𝐹 : 𝐵onto𝑌 ↔ ( 𝐹 : 𝐵𝑌 ∧ ∀ 𝑦𝑌𝑛𝐵 𝑦 = ( 𝐹𝑛 ) ) )
73 71 72 sylib ( 𝜑 → ( 𝐹 : 𝐵𝑌 ∧ ∀ 𝑦𝑌𝑛𝐵 𝑦 = ( 𝐹𝑛 ) ) )
74 73 simprd ( 𝜑 → ∀ 𝑦𝑌𝑛𝐵 𝑦 = ( 𝐹𝑛 ) )
75 74 adantr ( ( 𝜑𝑦𝑌 ) → ∀ 𝑦𝑌𝑛𝐵 𝑦 = ( 𝐹𝑛 ) )
76 simpr ( ( 𝜑𝑦𝑌 ) → 𝑦𝑌 )
77 rspa ( ( ∀ 𝑦𝑌𝑛𝐵 𝑦 = ( 𝐹𝑛 ) ∧ 𝑦𝑌 ) → ∃ 𝑛𝐵 𝑦 = ( 𝐹𝑛 ) )
78 75 76 77 syl2anc ( ( 𝜑𝑦𝑌 ) → ∃ 𝑛𝐵 𝑦 = ( 𝐹𝑛 ) )
79 78 adantlr ( ( ( 𝜑𝐵 = ℕ ) ∧ 𝑦𝑌 ) → ∃ 𝑛𝐵 𝑦 = ( 𝐹𝑛 ) )
80 nfv 𝑛 ( 𝜑𝐵 = ℕ )
81 nfre1 𝑛𝑛 ∈ ℕ 𝑦 = ( 𝐴𝑛 )
82 simpr ( ( 𝐵 = ℕ ∧ 𝑛𝐵 ) → 𝑛𝐵 )
83 simpl ( ( 𝐵 = ℕ ∧ 𝑛𝐵 ) → 𝐵 = ℕ )
84 82 83 eleqtrd ( ( 𝐵 = ℕ ∧ 𝑛𝐵 ) → 𝑛 ∈ ℕ )
85 84 adantll ( ( ( 𝜑𝐵 = ℕ ) ∧ 𝑛𝐵 ) → 𝑛 ∈ ℕ )
86 85 3adant3 ( ( ( 𝜑𝐵 = ℕ ) ∧ 𝑛𝐵𝑦 = ( 𝐹𝑛 ) ) → 𝑛 ∈ ℕ )
87 63 fveq1d ( 𝐵 = ℕ → ( 𝐴𝑛 ) = ( ( 𝑛 ∈ ℕ ↦ if ( 𝑛𝐵 , ( 𝐹𝑛 ) , ∅ ) ) ‘ 𝑛 ) )
88 87 3ad2ant1 ( ( 𝐵 = ℕ ∧ 𝑛𝐵𝑦 = ( 𝐹𝑛 ) ) → ( 𝐴𝑛 ) = ( ( 𝑛 ∈ ℕ ↦ if ( 𝑛𝐵 , ( 𝐹𝑛 ) , ∅ ) ) ‘ 𝑛 ) )
89 fvex ( 𝐹𝑛 ) ∈ V
90 89 21 ifex if ( 𝑛𝐵 , ( 𝐹𝑛 ) , ∅ ) ∈ V
91 90 a1i ( ( 𝐵 = ℕ ∧ 𝑛𝐵 ) → if ( 𝑛𝐵 , ( 𝐹𝑛 ) , ∅ ) ∈ V )
92 eqid ( 𝑛 ∈ ℕ ↦ if ( 𝑛𝐵 , ( 𝐹𝑛 ) , ∅ ) ) = ( 𝑛 ∈ ℕ ↦ if ( 𝑛𝐵 , ( 𝐹𝑛 ) , ∅ ) )
93 92 fvmpt2 ( ( 𝑛 ∈ ℕ ∧ if ( 𝑛𝐵 , ( 𝐹𝑛 ) , ∅ ) ∈ V ) → ( ( 𝑛 ∈ ℕ ↦ if ( 𝑛𝐵 , ( 𝐹𝑛 ) , ∅ ) ) ‘ 𝑛 ) = if ( 𝑛𝐵 , ( 𝐹𝑛 ) , ∅ ) )
94 84 91 93 syl2anc ( ( 𝐵 = ℕ ∧ 𝑛𝐵 ) → ( ( 𝑛 ∈ ℕ ↦ if ( 𝑛𝐵 , ( 𝐹𝑛 ) , ∅ ) ) ‘ 𝑛 ) = if ( 𝑛𝐵 , ( 𝐹𝑛 ) , ∅ ) )
95 9 adantl ( ( 𝐵 = ℕ ∧ 𝑛𝐵 ) → if ( 𝑛𝐵 , ( 𝐹𝑛 ) , ∅ ) = ( 𝐹𝑛 ) )
96 94 95 eqtrd ( ( 𝐵 = ℕ ∧ 𝑛𝐵 ) → ( ( 𝑛 ∈ ℕ ↦ if ( 𝑛𝐵 , ( 𝐹𝑛 ) , ∅ ) ) ‘ 𝑛 ) = ( 𝐹𝑛 ) )
97 96 3adant3 ( ( 𝐵 = ℕ ∧ 𝑛𝐵𝑦 = ( 𝐹𝑛 ) ) → ( ( 𝑛 ∈ ℕ ↦ if ( 𝑛𝐵 , ( 𝐹𝑛 ) , ∅ ) ) ‘ 𝑛 ) = ( 𝐹𝑛 ) )
98 id ( 𝑦 = ( 𝐹𝑛 ) → 𝑦 = ( 𝐹𝑛 ) )
99 98 eqcomd ( 𝑦 = ( 𝐹𝑛 ) → ( 𝐹𝑛 ) = 𝑦 )
100 99 3ad2ant3 ( ( 𝐵 = ℕ ∧ 𝑛𝐵𝑦 = ( 𝐹𝑛 ) ) → ( 𝐹𝑛 ) = 𝑦 )
101 88 97 100 3eqtrrd ( ( 𝐵 = ℕ ∧ 𝑛𝐵𝑦 = ( 𝐹𝑛 ) ) → 𝑦 = ( 𝐴𝑛 ) )
102 101 3adant1l ( ( ( 𝜑𝐵 = ℕ ) ∧ 𝑛𝐵𝑦 = ( 𝐹𝑛 ) ) → 𝑦 = ( 𝐴𝑛 ) )
103 rspe ( ( 𝑛 ∈ ℕ ∧ 𝑦 = ( 𝐴𝑛 ) ) → ∃ 𝑛 ∈ ℕ 𝑦 = ( 𝐴𝑛 ) )
104 86 102 103 syl2anc ( ( ( 𝜑𝐵 = ℕ ) ∧ 𝑛𝐵𝑦 = ( 𝐹𝑛 ) ) → ∃ 𝑛 ∈ ℕ 𝑦 = ( 𝐴𝑛 ) )
105 104 3exp ( ( 𝜑𝐵 = ℕ ) → ( 𝑛𝐵 → ( 𝑦 = ( 𝐹𝑛 ) → ∃ 𝑛 ∈ ℕ 𝑦 = ( 𝐴𝑛 ) ) ) )
106 80 81 105 rexlimd ( ( 𝜑𝐵 = ℕ ) → ( ∃ 𝑛𝐵 𝑦 = ( 𝐹𝑛 ) → ∃ 𝑛 ∈ ℕ 𝑦 = ( 𝐴𝑛 ) ) )
107 106 adantr ( ( ( 𝜑𝐵 = ℕ ) ∧ 𝑦𝑌 ) → ( ∃ 𝑛𝐵 𝑦 = ( 𝐹𝑛 ) → ∃ 𝑛 ∈ ℕ 𝑦 = ( 𝐴𝑛 ) ) )
108 79 107 mpd ( ( ( 𝜑𝐵 = ℕ ) ∧ 𝑦𝑌 ) → ∃ 𝑛 ∈ ℕ 𝑦 = ( 𝐴𝑛 ) )
109 108 ralrimiva ( ( 𝜑𝐵 = ℕ ) → ∀ 𝑦𝑌𝑛 ∈ ℕ 𝑦 = ( 𝐴𝑛 ) )
110 69 109 jca ( ( 𝜑𝐵 = ℕ ) → ( 𝐴 : ℕ ⟶ 𝑌 ∧ ∀ 𝑦𝑌𝑛 ∈ ℕ 𝑦 = ( 𝐴𝑛 ) ) )
111 dffo3 ( 𝐴 : ℕ –onto𝑌 ↔ ( 𝐴 : ℕ ⟶ 𝑌 ∧ ∀ 𝑦𝑌𝑛 ∈ ℕ 𝑦 = ( 𝐴𝑛 ) ) )
112 110 111 sylibr ( ( 𝜑𝐵 = ℕ ) → 𝐴 : ℕ –onto𝑌 )
113 founiiun ( 𝐴 : ℕ –onto𝑌 𝑌 = 𝑛 ∈ ℕ ( 𝐴𝑛 ) )
114 112 113 syl ( ( 𝜑𝐵 = ℕ ) → 𝑌 = 𝑛 ∈ ℕ ( 𝐴𝑛 ) )
115 uniun ( 𝑌 ∪ { ∅ } ) = ( 𝑌 { ∅ } )
116 21 unisn { ∅ } = ∅
117 116 uneq2i ( 𝑌 { ∅ } ) = ( 𝑌 ∪ ∅ )
118 un0 ( 𝑌 ∪ ∅ ) = 𝑌
119 115 117 118 3eqtrri 𝑌 = ( 𝑌 ∪ { ∅ } )
120 119 a1i ( ( 𝜑 ∧ ¬ 𝐵 = ℕ ) → 𝑌 = ( 𝑌 ∪ { ∅ } ) )
121 29 adantr ( ( 𝜑 ∧ ¬ 𝐵 = ℕ ) → 𝐴 : ℕ ⟶ ( 𝑌 ∪ { ∅ } ) )
122 nfv 𝑛 ( ( 𝜑 ∧ ¬ 𝐵 = ℕ ) ∧ 𝑦 = ∅ )
123 5 adantr ( ( 𝜑 ∧ ¬ 𝐵 = ℕ ) → 𝐵 ⊆ ℕ )
124 55 necon3bi ( ¬ 𝐵 = ℕ → 𝐵 ≠ ℕ )
125 124 adantl ( ( 𝜑 ∧ ¬ 𝐵 = ℕ ) → 𝐵 ≠ ℕ )
126 123 125 jca ( ( 𝜑 ∧ ¬ 𝐵 = ℕ ) → ( 𝐵 ⊆ ℕ ∧ 𝐵 ≠ ℕ ) )
127 df-pss ( 𝐵 ⊊ ℕ ↔ ( 𝐵 ⊆ ℕ ∧ 𝐵 ≠ ℕ ) )
128 126 127 sylibr ( ( 𝜑 ∧ ¬ 𝐵 = ℕ ) → 𝐵 ⊊ ℕ )
129 pssnel ( 𝐵 ⊊ ℕ → ∃ 𝑛 ( 𝑛 ∈ ℕ ∧ ¬ 𝑛𝐵 ) )
130 128 129 syl ( ( 𝜑 ∧ ¬ 𝐵 = ℕ ) → ∃ 𝑛 ( 𝑛 ∈ ℕ ∧ ¬ 𝑛𝐵 ) )
131 130 adantr ( ( ( 𝜑 ∧ ¬ 𝐵 = ℕ ) ∧ 𝑦 = ∅ ) → ∃ 𝑛 ( 𝑛 ∈ ℕ ∧ ¬ 𝑛𝐵 ) )
132 simprl ( ( ( 𝜑𝑦 = ∅ ) ∧ ( 𝑛 ∈ ℕ ∧ ¬ 𝑛𝐵 ) ) → 𝑛 ∈ ℕ )
133 simprl ( ( 𝜑 ∧ ( 𝑛 ∈ ℕ ∧ ¬ 𝑛𝐵 ) ) → 𝑛 ∈ ℕ )
134 90 a1i ( ( 𝜑 ∧ ( 𝑛 ∈ ℕ ∧ ¬ 𝑛𝐵 ) ) → if ( 𝑛𝐵 , ( 𝐹𝑛 ) , ∅ ) ∈ V )
135 7 fvmpt2 ( ( 𝑛 ∈ ℕ ∧ if ( 𝑛𝐵 , ( 𝐹𝑛 ) , ∅ ) ∈ V ) → ( 𝐴𝑛 ) = if ( 𝑛𝐵 , ( 𝐹𝑛 ) , ∅ ) )
136 133 134 135 syl2anc ( ( 𝜑 ∧ ( 𝑛 ∈ ℕ ∧ ¬ 𝑛𝐵 ) ) → ( 𝐴𝑛 ) = if ( 𝑛𝐵 , ( 𝐹𝑛 ) , ∅ ) )
137 136 adantlr ( ( ( 𝜑𝑦 = ∅ ) ∧ ( 𝑛 ∈ ℕ ∧ ¬ 𝑛𝐵 ) ) → ( 𝐴𝑛 ) = if ( 𝑛𝐵 , ( 𝐹𝑛 ) , ∅ ) )
138 19 ad2antll ( ( ( 𝜑𝑦 = ∅ ) ∧ ( 𝑛 ∈ ℕ ∧ ¬ 𝑛𝐵 ) ) → if ( 𝑛𝐵 , ( 𝐹𝑛 ) , ∅ ) = ∅ )
139 id ( 𝑦 = ∅ → 𝑦 = ∅ )
140 139 eqcomd ( 𝑦 = ∅ → ∅ = 𝑦 )
141 140 ad2antlr ( ( ( 𝜑𝑦 = ∅ ) ∧ ( 𝑛 ∈ ℕ ∧ ¬ 𝑛𝐵 ) ) → ∅ = 𝑦 )
142 137 138 141 3eqtrrd ( ( ( 𝜑𝑦 = ∅ ) ∧ ( 𝑛 ∈ ℕ ∧ ¬ 𝑛𝐵 ) ) → 𝑦 = ( 𝐴𝑛 ) )
143 132 142 103 syl2anc ( ( ( 𝜑𝑦 = ∅ ) ∧ ( 𝑛 ∈ ℕ ∧ ¬ 𝑛𝐵 ) ) → ∃ 𝑛 ∈ ℕ 𝑦 = ( 𝐴𝑛 ) )
144 143 ex ( ( 𝜑𝑦 = ∅ ) → ( ( 𝑛 ∈ ℕ ∧ ¬ 𝑛𝐵 ) → ∃ 𝑛 ∈ ℕ 𝑦 = ( 𝐴𝑛 ) ) )
145 144 adantlr ( ( ( 𝜑 ∧ ¬ 𝐵 = ℕ ) ∧ 𝑦 = ∅ ) → ( ( 𝑛 ∈ ℕ ∧ ¬ 𝑛𝐵 ) → ∃ 𝑛 ∈ ℕ 𝑦 = ( 𝐴𝑛 ) ) )
146 122 81 131 145 exlimimdd ( ( ( 𝜑 ∧ ¬ 𝐵 = ℕ ) ∧ 𝑦 = ∅ ) → ∃ 𝑛 ∈ ℕ 𝑦 = ( 𝐴𝑛 ) )
147 146 adantlr ( ( ( ( 𝜑 ∧ ¬ 𝐵 = ℕ ) ∧ 𝑦 ∈ ( 𝑌 ∪ { ∅ } ) ) ∧ 𝑦 = ∅ ) → ∃ 𝑛 ∈ ℕ 𝑦 = ( 𝐴𝑛 ) )
148 simplll ( ( ( ( 𝜑 ∧ ¬ 𝐵 = ℕ ) ∧ 𝑦 ∈ ( 𝑌 ∪ { ∅ } ) ) ∧ ¬ 𝑦 = ∅ ) → 𝜑 )
149 simpl ( ( 𝑦 ∈ ( 𝑌 ∪ { ∅ } ) ∧ ¬ 𝑦 = ∅ ) → 𝑦 ∈ ( 𝑌 ∪ { ∅ } ) )
150 elsni ( 𝑦 ∈ { ∅ } → 𝑦 = ∅ )
151 150 con3i ( ¬ 𝑦 = ∅ → ¬ 𝑦 ∈ { ∅ } )
152 151 adantl ( ( 𝑦 ∈ ( 𝑌 ∪ { ∅ } ) ∧ ¬ 𝑦 = ∅ ) → ¬ 𝑦 ∈ { ∅ } )
153 elunnel2 ( ( 𝑦 ∈ ( 𝑌 ∪ { ∅ } ) ∧ ¬ 𝑦 ∈ { ∅ } ) → 𝑦𝑌 )
154 149 152 153 syl2anc ( ( 𝑦 ∈ ( 𝑌 ∪ { ∅ } ) ∧ ¬ 𝑦 = ∅ ) → 𝑦𝑌 )
155 154 adantll ( ( ( ( 𝜑 ∧ ¬ 𝐵 = ℕ ) ∧ 𝑦 ∈ ( 𝑌 ∪ { ∅ } ) ) ∧ ¬ 𝑦 = ∅ ) → 𝑦𝑌 )
156 71 adantr ( ( 𝜑𝑦𝑌 ) → 𝐹 : 𝐵onto𝑌 )
157 foelrni ( ( 𝐹 : 𝐵onto𝑌𝑦𝑌 ) → ∃ 𝑛𝐵 ( 𝐹𝑛 ) = 𝑦 )
158 156 76 157 syl2anc ( ( 𝜑𝑦𝑌 ) → ∃ 𝑛𝐵 ( 𝐹𝑛 ) = 𝑦 )
159 nfv 𝑛 ( 𝜑𝑦𝑌 )
160 5 sselda ( ( 𝜑𝑛𝐵 ) → 𝑛 ∈ ℕ )
161 160 3adant3 ( ( 𝜑𝑛𝐵 ∧ ( 𝐹𝑛 ) = 𝑦 ) → 𝑛 ∈ ℕ )
162 160 90 135 sylancl ( ( 𝜑𝑛𝐵 ) → ( 𝐴𝑛 ) = if ( 𝑛𝐵 , ( 𝐹𝑛 ) , ∅ ) )
163 162 10 eqtrd ( ( 𝜑𝑛𝐵 ) → ( 𝐴𝑛 ) = ( 𝐹𝑛 ) )
164 163 3adant3 ( ( 𝜑𝑛𝐵 ∧ ( 𝐹𝑛 ) = 𝑦 ) → ( 𝐴𝑛 ) = ( 𝐹𝑛 ) )
165 simp3 ( ( 𝜑𝑛𝐵 ∧ ( 𝐹𝑛 ) = 𝑦 ) → ( 𝐹𝑛 ) = 𝑦 )
166 164 165 eqtr2d ( ( 𝜑𝑛𝐵 ∧ ( 𝐹𝑛 ) = 𝑦 ) → 𝑦 = ( 𝐴𝑛 ) )
167 161 166 103 syl2anc ( ( 𝜑𝑛𝐵 ∧ ( 𝐹𝑛 ) = 𝑦 ) → ∃ 𝑛 ∈ ℕ 𝑦 = ( 𝐴𝑛 ) )
168 167 3exp ( 𝜑 → ( 𝑛𝐵 → ( ( 𝐹𝑛 ) = 𝑦 → ∃ 𝑛 ∈ ℕ 𝑦 = ( 𝐴𝑛 ) ) ) )
169 168 adantr ( ( 𝜑𝑦𝑌 ) → ( 𝑛𝐵 → ( ( 𝐹𝑛 ) = 𝑦 → ∃ 𝑛 ∈ ℕ 𝑦 = ( 𝐴𝑛 ) ) ) )
170 159 81 169 rexlimd ( ( 𝜑𝑦𝑌 ) → ( ∃ 𝑛𝐵 ( 𝐹𝑛 ) = 𝑦 → ∃ 𝑛 ∈ ℕ 𝑦 = ( 𝐴𝑛 ) ) )
171 158 170 mpd ( ( 𝜑𝑦𝑌 ) → ∃ 𝑛 ∈ ℕ 𝑦 = ( 𝐴𝑛 ) )
172 148 155 171 syl2anc ( ( ( ( 𝜑 ∧ ¬ 𝐵 = ℕ ) ∧ 𝑦 ∈ ( 𝑌 ∪ { ∅ } ) ) ∧ ¬ 𝑦 = ∅ ) → ∃ 𝑛 ∈ ℕ 𝑦 = ( 𝐴𝑛 ) )
173 147 172 pm2.61dan ( ( ( 𝜑 ∧ ¬ 𝐵 = ℕ ) ∧ 𝑦 ∈ ( 𝑌 ∪ { ∅ } ) ) → ∃ 𝑛 ∈ ℕ 𝑦 = ( 𝐴𝑛 ) )
174 173 ralrimiva ( ( 𝜑 ∧ ¬ 𝐵 = ℕ ) → ∀ 𝑦 ∈ ( 𝑌 ∪ { ∅ } ) ∃ 𝑛 ∈ ℕ 𝑦 = ( 𝐴𝑛 ) )
175 121 174 jca ( ( 𝜑 ∧ ¬ 𝐵 = ℕ ) → ( 𝐴 : ℕ ⟶ ( 𝑌 ∪ { ∅ } ) ∧ ∀ 𝑦 ∈ ( 𝑌 ∪ { ∅ } ) ∃ 𝑛 ∈ ℕ 𝑦 = ( 𝐴𝑛 ) ) )
176 dffo3 ( 𝐴 : ℕ –onto→ ( 𝑌 ∪ { ∅ } ) ↔ ( 𝐴 : ℕ ⟶ ( 𝑌 ∪ { ∅ } ) ∧ ∀ 𝑦 ∈ ( 𝑌 ∪ { ∅ } ) ∃ 𝑛 ∈ ℕ 𝑦 = ( 𝐴𝑛 ) ) )
177 175 176 sylibr ( ( 𝜑 ∧ ¬ 𝐵 = ℕ ) → 𝐴 : ℕ –onto→ ( 𝑌 ∪ { ∅ } ) )
178 founiiun ( 𝐴 : ℕ –onto→ ( 𝑌 ∪ { ∅ } ) → ( 𝑌 ∪ { ∅ } ) = 𝑛 ∈ ℕ ( 𝐴𝑛 ) )
179 177 178 syl ( ( 𝜑 ∧ ¬ 𝐵 = ℕ ) → ( 𝑌 ∪ { ∅ } ) = 𝑛 ∈ ℕ ( 𝐴𝑛 ) )
180 120 179 eqtrd ( ( 𝜑 ∧ ¬ 𝐵 = ℕ ) → 𝑌 = 𝑛 ∈ ℕ ( 𝐴𝑛 ) )
181 114 180 pm2.61dan ( 𝜑 𝑌 = 𝑛 ∈ ℕ ( 𝐴𝑛 ) )
182 181 fveq2d ( 𝜑 → ( 𝑂 𝑌 ) = ( 𝑂 𝑛 ∈ ℕ ( 𝐴𝑛 ) ) )
183 uncom ( ( ℕ ∖ 𝐵 ) ∪ 𝐵 ) = ( 𝐵 ∪ ( ℕ ∖ 𝐵 ) )
184 183 a1i ( 𝜑 → ( ( ℕ ∖ 𝐵 ) ∪ 𝐵 ) = ( 𝐵 ∪ ( ℕ ∖ 𝐵 ) ) )
185 undif ( 𝐵 ⊆ ℕ ↔ ( 𝐵 ∪ ( ℕ ∖ 𝐵 ) ) = ℕ )
186 5 185 sylib ( 𝜑 → ( 𝐵 ∪ ( ℕ ∖ 𝐵 ) ) = ℕ )
187 184 186 eqtrd ( 𝜑 → ( ( ℕ ∖ 𝐵 ) ∪ 𝐵 ) = ℕ )
188 187 eqcomd ( 𝜑 → ℕ = ( ( ℕ ∖ 𝐵 ) ∪ 𝐵 ) )
189 188 mpteq1d ( 𝜑 → ( 𝑛 ∈ ℕ ↦ ( 𝑂 ‘ ( 𝐴𝑛 ) ) ) = ( 𝑛 ∈ ( ( ℕ ∖ 𝐵 ) ∪ 𝐵 ) ↦ ( 𝑂 ‘ ( 𝐴𝑛 ) ) ) )
190 189 fveq2d ( 𝜑 → ( Σ^ ‘ ( 𝑛 ∈ ℕ ↦ ( 𝑂 ‘ ( 𝐴𝑛 ) ) ) ) = ( Σ^ ‘ ( 𝑛 ∈ ( ( ℕ ∖ 𝐵 ) ∪ 𝐵 ) ↦ ( 𝑂 ‘ ( 𝐴𝑛 ) ) ) ) )
191 nfv 𝑛 𝜑
192 difexg ( ℕ ∈ V → ( ℕ ∖ 𝐵 ) ∈ V )
193 36 192 ax-mp ( ℕ ∖ 𝐵 ) ∈ V
194 193 a1i ( 𝜑 → ( ℕ ∖ 𝐵 ) ∈ V )
195 36 a1i ( 𝜑 → ℕ ∈ V )
196 195 5 ssexd ( 𝜑𝐵 ∈ V )
197 disjdifr ( ( ℕ ∖ 𝐵 ) ∩ 𝐵 ) = ∅
198 197 a1i ( 𝜑 → ( ( ℕ ∖ 𝐵 ) ∩ 𝐵 ) = ∅ )
199 simpl ( ( 𝜑𝑛 ∈ ( ℕ ∖ 𝐵 ) ) → 𝜑 )
200 eldifi ( 𝑛 ∈ ( ℕ ∖ 𝐵 ) → 𝑛 ∈ ℕ )
201 200 adantl ( ( 𝜑𝑛 ∈ ( ℕ ∖ 𝐵 ) ) → 𝑛 ∈ ℕ )
202 1 adantr ( ( 𝜑𝑛 ∈ ℕ ) → 𝑂 : 𝒫 𝑋 ⟶ ( 0 [,] +∞ ) )
203 35 ffvelrnda ( ( 𝜑𝑛 ∈ ℕ ) → ( 𝐴𝑛 ) ∈ 𝒫 𝑋 )
204 202 203 ffvelrnd ( ( 𝜑𝑛 ∈ ℕ ) → ( 𝑂 ‘ ( 𝐴𝑛 ) ) ∈ ( 0 [,] +∞ ) )
205 199 201 204 syl2anc ( ( 𝜑𝑛 ∈ ( ℕ ∖ 𝐵 ) ) → ( 𝑂 ‘ ( 𝐴𝑛 ) ) ∈ ( 0 [,] +∞ ) )
206 160 204 syldan ( ( 𝜑𝑛𝐵 ) → ( 𝑂 ‘ ( 𝐴𝑛 ) ) ∈ ( 0 [,] +∞ ) )
207 191 194 196 198 205 206 sge0splitmpt ( 𝜑 → ( Σ^ ‘ ( 𝑛 ∈ ( ( ℕ ∖ 𝐵 ) ∪ 𝐵 ) ↦ ( 𝑂 ‘ ( 𝐴𝑛 ) ) ) ) = ( ( Σ^ ‘ ( 𝑛 ∈ ( ℕ ∖ 𝐵 ) ↦ ( 𝑂 ‘ ( 𝐴𝑛 ) ) ) ) +𝑒 ( Σ^ ‘ ( 𝑛𝐵 ↦ ( 𝑂 ‘ ( 𝐴𝑛 ) ) ) ) ) )
208 eqid ( 𝑛𝐵 ↦ ( 𝑂 ‘ ( 𝐴𝑛 ) ) ) = ( 𝑛𝐵 ↦ ( 𝑂 ‘ ( 𝐴𝑛 ) ) )
209 206 208 fmptd ( 𝜑 → ( 𝑛𝐵 ↦ ( 𝑂 ‘ ( 𝐴𝑛 ) ) ) : 𝐵 ⟶ ( 0 [,] +∞ ) )
210 196 209 sge0xrcl ( 𝜑 → ( Σ^ ‘ ( 𝑛𝐵 ↦ ( 𝑂 ‘ ( 𝐴𝑛 ) ) ) ) ∈ ℝ* )
211 210 xaddid2d ( 𝜑 → ( 0 +𝑒 ( Σ^ ‘ ( 𝑛𝐵 ↦ ( 𝑂 ‘ ( 𝐴𝑛 ) ) ) ) ) = ( Σ^ ‘ ( 𝑛𝐵 ↦ ( 𝑂 ‘ ( 𝐴𝑛 ) ) ) ) )
212 90 a1i ( ( 𝜑𝑛 ∈ ( ℕ ∖ 𝐵 ) ) → if ( 𝑛𝐵 , ( 𝐹𝑛 ) , ∅ ) ∈ V )
213 201 212 135 syl2anc ( ( 𝜑𝑛 ∈ ( ℕ ∖ 𝐵 ) ) → ( 𝐴𝑛 ) = if ( 𝑛𝐵 , ( 𝐹𝑛 ) , ∅ ) )
214 eldifn ( 𝑛 ∈ ( ℕ ∖ 𝐵 ) → ¬ 𝑛𝐵 )
215 214 adantl ( ( 𝜑𝑛 ∈ ( ℕ ∖ 𝐵 ) ) → ¬ 𝑛𝐵 )
216 215 iffalsed ( ( 𝜑𝑛 ∈ ( ℕ ∖ 𝐵 ) ) → if ( 𝑛𝐵 , ( 𝐹𝑛 ) , ∅ ) = ∅ )
217 213 216 eqtrd ( ( 𝜑𝑛 ∈ ( ℕ ∖ 𝐵 ) ) → ( 𝐴𝑛 ) = ∅ )
218 217 fveq2d ( ( 𝜑𝑛 ∈ ( ℕ ∖ 𝐵 ) ) → ( 𝑂 ‘ ( 𝐴𝑛 ) ) = ( 𝑂 ‘ ∅ ) )
219 199 2 syl ( ( 𝜑𝑛 ∈ ( ℕ ∖ 𝐵 ) ) → ( 𝑂 ‘ ∅ ) = 0 )
220 218 219 eqtrd ( ( 𝜑𝑛 ∈ ( ℕ ∖ 𝐵 ) ) → ( 𝑂 ‘ ( 𝐴𝑛 ) ) = 0 )
221 220 mpteq2dva ( 𝜑 → ( 𝑛 ∈ ( ℕ ∖ 𝐵 ) ↦ ( 𝑂 ‘ ( 𝐴𝑛 ) ) ) = ( 𝑛 ∈ ( ℕ ∖ 𝐵 ) ↦ 0 ) )
222 221 fveq2d ( 𝜑 → ( Σ^ ‘ ( 𝑛 ∈ ( ℕ ∖ 𝐵 ) ↦ ( 𝑂 ‘ ( 𝐴𝑛 ) ) ) ) = ( Σ^ ‘ ( 𝑛 ∈ ( ℕ ∖ 𝐵 ) ↦ 0 ) ) )
223 191 194 sge0z ( 𝜑 → ( Σ^ ‘ ( 𝑛 ∈ ( ℕ ∖ 𝐵 ) ↦ 0 ) ) = 0 )
224 222 223 eqtrd ( 𝜑 → ( Σ^ ‘ ( 𝑛 ∈ ( ℕ ∖ 𝐵 ) ↦ ( 𝑂 ‘ ( 𝐴𝑛 ) ) ) ) = 0 )
225 224 oveq1d ( 𝜑 → ( ( Σ^ ‘ ( 𝑛 ∈ ( ℕ ∖ 𝐵 ) ↦ ( 𝑂 ‘ ( 𝐴𝑛 ) ) ) ) +𝑒 ( Σ^ ‘ ( 𝑛𝐵 ↦ ( 𝑂 ‘ ( 𝐴𝑛 ) ) ) ) ) = ( 0 +𝑒 ( Σ^ ‘ ( 𝑛𝐵 ↦ ( 𝑂 ‘ ( 𝐴𝑛 ) ) ) ) ) )
226 1 3 feqresmpt ( 𝜑 → ( 𝑂𝑌 ) = ( 𝑦𝑌 ↦ ( 𝑂𝑦 ) ) )
227 226 fveq2d ( 𝜑 → ( Σ^ ‘ ( 𝑂𝑌 ) ) = ( Σ^ ‘ ( 𝑦𝑌 ↦ ( 𝑂𝑦 ) ) ) )
228 nfv 𝑦 𝜑
229 fveq2 ( 𝑦 = ( 𝐴𝑛 ) → ( 𝑂𝑦 ) = ( 𝑂 ‘ ( 𝐴𝑛 ) ) )
230 163 eqcomd ( ( 𝜑𝑛𝐵 ) → ( 𝐹𝑛 ) = ( 𝐴𝑛 ) )
231 1 adantr ( ( 𝜑𝑦𝑌 ) → 𝑂 : 𝒫 𝑋 ⟶ ( 0 [,] +∞ ) )
232 3 sselda ( ( 𝜑𝑦𝑌 ) → 𝑦 ∈ 𝒫 𝑋 )
233 231 232 ffvelrnd ( ( 𝜑𝑦𝑌 ) → ( 𝑂𝑦 ) ∈ ( 0 [,] +∞ ) )
234 228 191 229 196 6 230 233 sge0f1o ( 𝜑 → ( Σ^ ‘ ( 𝑦𝑌 ↦ ( 𝑂𝑦 ) ) ) = ( Σ^ ‘ ( 𝑛𝐵 ↦ ( 𝑂 ‘ ( 𝐴𝑛 ) ) ) ) )
235 eqidd ( 𝜑 → ( Σ^ ‘ ( 𝑛𝐵 ↦ ( 𝑂 ‘ ( 𝐴𝑛 ) ) ) ) = ( Σ^ ‘ ( 𝑛𝐵 ↦ ( 𝑂 ‘ ( 𝐴𝑛 ) ) ) ) )
236 227 234 235 3eqtrd ( 𝜑 → ( Σ^ ‘ ( 𝑂𝑌 ) ) = ( Σ^ ‘ ( 𝑛𝐵 ↦ ( 𝑂 ‘ ( 𝐴𝑛 ) ) ) ) )
237 211 225 236 3eqtr4d ( 𝜑 → ( ( Σ^ ‘ ( 𝑛 ∈ ( ℕ ∖ 𝐵 ) ↦ ( 𝑂 ‘ ( 𝐴𝑛 ) ) ) ) +𝑒 ( Σ^ ‘ ( 𝑛𝐵 ↦ ( 𝑂 ‘ ( 𝐴𝑛 ) ) ) ) ) = ( Σ^ ‘ ( 𝑂𝑌 ) ) )
238 190 207 237 3eqtrrd ( 𝜑 → ( Σ^ ‘ ( 𝑂𝑌 ) ) = ( Σ^ ‘ ( 𝑛 ∈ ℕ ↦ ( 𝑂 ‘ ( 𝐴𝑛 ) ) ) ) )
239 182 238 breq12d ( 𝜑 → ( ( 𝑂 𝑌 ) ≤ ( Σ^ ‘ ( 𝑂𝑌 ) ) ↔ ( 𝑂 𝑛 ∈ ℕ ( 𝐴𝑛 ) ) ≤ ( Σ^ ‘ ( 𝑛 ∈ ℕ ↦ ( 𝑂 ‘ ( 𝐴𝑛 ) ) ) ) ) )
240 52 239 mpbird ( 𝜑 → ( 𝑂 𝑌 ) ≤ ( Σ^ ‘ ( 𝑂𝑌 ) ) )