Metamath Proof Explorer


Theorem ovnovollem3

Description: The 1-dimensional Lebesgue outer measure agrees with the Lebesgue outer measure on subsets of Real numbers. (Contributed by Glauco Siliprandi, 3-Mar-2021)

Ref Expression
Hypotheses ovnovollem3.a ( 𝜑𝐴𝑉 )
ovnovollem3.b ( 𝜑𝐵 ⊆ ℝ )
ovnovollem3.m 𝑀 = { 𝑧 ∈ ℝ* ∣ ∃ 𝑖 ∈ ( ( ( ℝ × ℝ ) ↑m { 𝐴 } ) ↑m ℕ ) ( ( 𝐵m { 𝐴 } ) ⊆ 𝑗 ∈ ℕ X 𝑘 ∈ { 𝐴 } ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) ∧ 𝑧 = ( Σ^ ‘ ( 𝑗 ∈ ℕ ↦ ∏ 𝑘 ∈ { 𝐴 } ( vol ‘ ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) ) ) ) ) }
ovnovollem3.n 𝑁 = { 𝑧 ∈ ℝ* ∣ ∃ 𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) ( 𝐵 ran ( [,) ∘ 𝑓 ) ∧ 𝑧 = ( Σ^ ‘ ( ( vol ∘ [,) ) ∘ 𝑓 ) ) ) }
Assertion ovnovollem3 ( 𝜑 → ( ( voln* ‘ { 𝐴 } ) ‘ ( 𝐵m { 𝐴 } ) ) = ( vol* ‘ 𝐵 ) )

Proof

Step Hyp Ref Expression
1 ovnovollem3.a ( 𝜑𝐴𝑉 )
2 ovnovollem3.b ( 𝜑𝐵 ⊆ ℝ )
3 ovnovollem3.m 𝑀 = { 𝑧 ∈ ℝ* ∣ ∃ 𝑖 ∈ ( ( ( ℝ × ℝ ) ↑m { 𝐴 } ) ↑m ℕ ) ( ( 𝐵m { 𝐴 } ) ⊆ 𝑗 ∈ ℕ X 𝑘 ∈ { 𝐴 } ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) ∧ 𝑧 = ( Σ^ ‘ ( 𝑗 ∈ ℕ ↦ ∏ 𝑘 ∈ { 𝐴 } ( vol ‘ ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) ) ) ) ) }
4 ovnovollem3.n 𝑁 = { 𝑧 ∈ ℝ* ∣ ∃ 𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) ( 𝐵 ran ( [,) ∘ 𝑓 ) ∧ 𝑧 = ( Σ^ ‘ ( ( vol ∘ [,) ) ∘ 𝑓 ) ) ) }
5 1 snn0d ( 𝜑 → { 𝐴 } ≠ ∅ )
6 5 neneqd ( 𝜑 → ¬ { 𝐴 } = ∅ )
7 6 iffalsed ( 𝜑 → if ( { 𝐴 } = ∅ , 0 , inf ( 𝑀 , ℝ* , < ) ) = inf ( 𝑀 , ℝ* , < ) )
8 snfi { 𝐴 } ∈ Fin
9 8 a1i ( 𝜑 → { 𝐴 } ∈ Fin )
10 reex ℝ ∈ V
11 10 a1i ( 𝜑 → ℝ ∈ V )
12 mapss ( ( ℝ ∈ V ∧ 𝐵 ⊆ ℝ ) → ( 𝐵m { 𝐴 } ) ⊆ ( ℝ ↑m { 𝐴 } ) )
13 11 2 12 syl2anc ( 𝜑 → ( 𝐵m { 𝐴 } ) ⊆ ( ℝ ↑m { 𝐴 } ) )
14 9 13 3 ovnval2 ( 𝜑 → ( ( voln* ‘ { 𝐴 } ) ‘ ( 𝐵m { 𝐴 } ) ) = if ( { 𝐴 } = ∅ , 0 , inf ( 𝑀 , ℝ* , < ) ) )
15 2 4 ovolval5 ( 𝜑 → ( vol* ‘ 𝐵 ) = inf ( 𝑁 , ℝ* , < ) )
16 1 ad2antrr ( ( ( 𝜑𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) ) ∧ ( 𝐵 ran ( [,) ∘ 𝑓 ) ∧ 𝑧 = ( Σ^ ‘ ( ( vol ∘ [,) ) ∘ 𝑓 ) ) ) ) → 𝐴𝑉 )
17 simplr ( ( ( 𝜑𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) ) ∧ ( 𝐵 ran ( [,) ∘ 𝑓 ) ∧ 𝑧 = ( Σ^ ‘ ( ( vol ∘ [,) ) ∘ 𝑓 ) ) ) ) → 𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) )
18 fveq2 ( 𝑛 = 𝑗 → ( 𝑓𝑛 ) = ( 𝑓𝑗 ) )
19 18 opeq2d ( 𝑛 = 𝑗 → ⟨ 𝐴 , ( 𝑓𝑛 ) ⟩ = ⟨ 𝐴 , ( 𝑓𝑗 ) ⟩ )
20 19 sneqd ( 𝑛 = 𝑗 → { ⟨ 𝐴 , ( 𝑓𝑛 ) ⟩ } = { ⟨ 𝐴 , ( 𝑓𝑗 ) ⟩ } )
21 20 cbvmptv ( 𝑛 ∈ ℕ ↦ { ⟨ 𝐴 , ( 𝑓𝑛 ) ⟩ } ) = ( 𝑗 ∈ ℕ ↦ { ⟨ 𝐴 , ( 𝑓𝑗 ) ⟩ } )
22 simprl ( ( ( 𝜑𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) ) ∧ ( 𝐵 ran ( [,) ∘ 𝑓 ) ∧ 𝑧 = ( Σ^ ‘ ( ( vol ∘ [,) ) ∘ 𝑓 ) ) ) ) → 𝐵 ran ( [,) ∘ 𝑓 ) )
23 11 2 ssexd ( 𝜑𝐵 ∈ V )
24 23 adantr ( ( 𝜑𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) ) → 𝐵 ∈ V )
25 24 adantr ( ( ( 𝜑𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) ) ∧ ( 𝐵 ran ( [,) ∘ 𝑓 ) ∧ 𝑧 = ( Σ^ ‘ ( ( vol ∘ [,) ) ∘ 𝑓 ) ) ) ) → 𝐵 ∈ V )
26 simprr ( ( ( 𝜑𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) ) ∧ ( 𝐵 ran ( [,) ∘ 𝑓 ) ∧ 𝑧 = ( Σ^ ‘ ( ( vol ∘ [,) ) ∘ 𝑓 ) ) ) ) → 𝑧 = ( Σ^ ‘ ( ( vol ∘ [,) ) ∘ 𝑓 ) ) )
27 16 17 21 22 25 26 ovnovollem1 ( ( ( 𝜑𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) ) ∧ ( 𝐵 ran ( [,) ∘ 𝑓 ) ∧ 𝑧 = ( Σ^ ‘ ( ( vol ∘ [,) ) ∘ 𝑓 ) ) ) ) → ∃ 𝑖 ∈ ( ( ( ℝ × ℝ ) ↑m { 𝐴 } ) ↑m ℕ ) ( ( 𝐵m { 𝐴 } ) ⊆ 𝑗 ∈ ℕ X 𝑘 ∈ { 𝐴 } ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) ∧ 𝑧 = ( Σ^ ‘ ( 𝑗 ∈ ℕ ↦ ∏ 𝑘 ∈ { 𝐴 } ( vol ‘ ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) ) ) ) ) )
28 27 rexlimdva2 ( 𝜑 → ( ∃ 𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) ( 𝐵 ran ( [,) ∘ 𝑓 ) ∧ 𝑧 = ( Σ^ ‘ ( ( vol ∘ [,) ) ∘ 𝑓 ) ) ) → ∃ 𝑖 ∈ ( ( ( ℝ × ℝ ) ↑m { 𝐴 } ) ↑m ℕ ) ( ( 𝐵m { 𝐴 } ) ⊆ 𝑗 ∈ ℕ X 𝑘 ∈ { 𝐴 } ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) ∧ 𝑧 = ( Σ^ ‘ ( 𝑗 ∈ ℕ ↦ ∏ 𝑘 ∈ { 𝐴 } ( vol ‘ ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) ) ) ) ) ) )
29 1 3ad2ant1 ( ( 𝜑𝑖 ∈ ( ( ( ℝ × ℝ ) ↑m { 𝐴 } ) ↑m ℕ ) ∧ ( ( 𝐵m { 𝐴 } ) ⊆ 𝑗 ∈ ℕ X 𝑘 ∈ { 𝐴 } ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) ∧ 𝑧 = ( Σ^ ‘ ( 𝑗 ∈ ℕ ↦ ∏ 𝑘 ∈ { 𝐴 } ( vol ‘ ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) ) ) ) ) ) → 𝐴𝑉 )
30 23 3ad2ant1 ( ( 𝜑𝑖 ∈ ( ( ( ℝ × ℝ ) ↑m { 𝐴 } ) ↑m ℕ ) ∧ ( ( 𝐵m { 𝐴 } ) ⊆ 𝑗 ∈ ℕ X 𝑘 ∈ { 𝐴 } ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) ∧ 𝑧 = ( Σ^ ‘ ( 𝑗 ∈ ℕ ↦ ∏ 𝑘 ∈ { 𝐴 } ( vol ‘ ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) ) ) ) ) ) → 𝐵 ∈ V )
31 simp2 ( ( 𝜑𝑖 ∈ ( ( ( ℝ × ℝ ) ↑m { 𝐴 } ) ↑m ℕ ) ∧ ( ( 𝐵m { 𝐴 } ) ⊆ 𝑗 ∈ ℕ X 𝑘 ∈ { 𝐴 } ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) ∧ 𝑧 = ( Σ^ ‘ ( 𝑗 ∈ ℕ ↦ ∏ 𝑘 ∈ { 𝐴 } ( vol ‘ ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) ) ) ) ) ) → 𝑖 ∈ ( ( ( ℝ × ℝ ) ↑m { 𝐴 } ) ↑m ℕ ) )
32 simp3l ( ( 𝜑𝑖 ∈ ( ( ( ℝ × ℝ ) ↑m { 𝐴 } ) ↑m ℕ ) ∧ ( ( 𝐵m { 𝐴 } ) ⊆ 𝑗 ∈ ℕ X 𝑘 ∈ { 𝐴 } ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) ∧ 𝑧 = ( Σ^ ‘ ( 𝑗 ∈ ℕ ↦ ∏ 𝑘 ∈ { 𝐴 } ( vol ‘ ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) ) ) ) ) ) → ( 𝐵m { 𝐴 } ) ⊆ 𝑗 ∈ ℕ X 𝑘 ∈ { 𝐴 } ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) )
33 fveq2 ( 𝑗 = 𝑛 → ( 𝑖𝑗 ) = ( 𝑖𝑛 ) )
34 33 coeq2d ( 𝑗 = 𝑛 → ( [,) ∘ ( 𝑖𝑗 ) ) = ( [,) ∘ ( 𝑖𝑛 ) ) )
35 34 fveq1d ( 𝑗 = 𝑛 → ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) = ( ( [,) ∘ ( 𝑖𝑛 ) ) ‘ 𝑘 ) )
36 35 ixpeq2dv ( 𝑗 = 𝑛X 𝑘 ∈ { 𝐴 } ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) = X 𝑘 ∈ { 𝐴 } ( ( [,) ∘ ( 𝑖𝑛 ) ) ‘ 𝑘 ) )
37 fveq2 ( 𝑘 = 𝑙 → ( ( [,) ∘ ( 𝑖𝑛 ) ) ‘ 𝑘 ) = ( ( [,) ∘ ( 𝑖𝑛 ) ) ‘ 𝑙 ) )
38 37 cbvixpv X 𝑘 ∈ { 𝐴 } ( ( [,) ∘ ( 𝑖𝑛 ) ) ‘ 𝑘 ) = X 𝑙 ∈ { 𝐴 } ( ( [,) ∘ ( 𝑖𝑛 ) ) ‘ 𝑙 )
39 38 a1i ( 𝑗 = 𝑛X 𝑘 ∈ { 𝐴 } ( ( [,) ∘ ( 𝑖𝑛 ) ) ‘ 𝑘 ) = X 𝑙 ∈ { 𝐴 } ( ( [,) ∘ ( 𝑖𝑛 ) ) ‘ 𝑙 ) )
40 36 39 eqtrd ( 𝑗 = 𝑛X 𝑘 ∈ { 𝐴 } ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) = X 𝑙 ∈ { 𝐴 } ( ( [,) ∘ ( 𝑖𝑛 ) ) ‘ 𝑙 ) )
41 40 cbviunv 𝑗 ∈ ℕ X 𝑘 ∈ { 𝐴 } ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) = 𝑛 ∈ ℕ X 𝑙 ∈ { 𝐴 } ( ( [,) ∘ ( 𝑖𝑛 ) ) ‘ 𝑙 )
42 41 sseq2i ( ( 𝐵m { 𝐴 } ) ⊆ 𝑗 ∈ ℕ X 𝑘 ∈ { 𝐴 } ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) ↔ ( 𝐵m { 𝐴 } ) ⊆ 𝑛 ∈ ℕ X 𝑙 ∈ { 𝐴 } ( ( [,) ∘ ( 𝑖𝑛 ) ) ‘ 𝑙 ) )
43 42 biimpi ( ( 𝐵m { 𝐴 } ) ⊆ 𝑗 ∈ ℕ X 𝑘 ∈ { 𝐴 } ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) → ( 𝐵m { 𝐴 } ) ⊆ 𝑛 ∈ ℕ X 𝑙 ∈ { 𝐴 } ( ( [,) ∘ ( 𝑖𝑛 ) ) ‘ 𝑙 ) )
44 32 43 syl ( ( 𝜑𝑖 ∈ ( ( ( ℝ × ℝ ) ↑m { 𝐴 } ) ↑m ℕ ) ∧ ( ( 𝐵m { 𝐴 } ) ⊆ 𝑗 ∈ ℕ X 𝑘 ∈ { 𝐴 } ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) ∧ 𝑧 = ( Σ^ ‘ ( 𝑗 ∈ ℕ ↦ ∏ 𝑘 ∈ { 𝐴 } ( vol ‘ ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) ) ) ) ) ) → ( 𝐵m { 𝐴 } ) ⊆ 𝑛 ∈ ℕ X 𝑙 ∈ { 𝐴 } ( ( [,) ∘ ( 𝑖𝑛 ) ) ‘ 𝑙 ) )
45 simp3r ( ( 𝜑𝑖 ∈ ( ( ( ℝ × ℝ ) ↑m { 𝐴 } ) ↑m ℕ ) ∧ ( ( 𝐵m { 𝐴 } ) ⊆ 𝑗 ∈ ℕ X 𝑘 ∈ { 𝐴 } ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) ∧ 𝑧 = ( Σ^ ‘ ( 𝑗 ∈ ℕ ↦ ∏ 𝑘 ∈ { 𝐴 } ( vol ‘ ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) ) ) ) ) ) → 𝑧 = ( Σ^ ‘ ( 𝑗 ∈ ℕ ↦ ∏ 𝑘 ∈ { 𝐴 } ( vol ‘ ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) ) ) ) )
46 35 fveq2d ( 𝑗 = 𝑛 → ( vol ‘ ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) ) = ( vol ‘ ( ( [,) ∘ ( 𝑖𝑛 ) ) ‘ 𝑘 ) ) )
47 46 prodeq2ad ( 𝑗 = 𝑛 → ∏ 𝑘 ∈ { 𝐴 } ( vol ‘ ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) ) = ∏ 𝑘 ∈ { 𝐴 } ( vol ‘ ( ( [,) ∘ ( 𝑖𝑛 ) ) ‘ 𝑘 ) ) )
48 37 fveq2d ( 𝑘 = 𝑙 → ( vol ‘ ( ( [,) ∘ ( 𝑖𝑛 ) ) ‘ 𝑘 ) ) = ( vol ‘ ( ( [,) ∘ ( 𝑖𝑛 ) ) ‘ 𝑙 ) ) )
49 48 cbvprodv 𝑘 ∈ { 𝐴 } ( vol ‘ ( ( [,) ∘ ( 𝑖𝑛 ) ) ‘ 𝑘 ) ) = ∏ 𝑙 ∈ { 𝐴 } ( vol ‘ ( ( [,) ∘ ( 𝑖𝑛 ) ) ‘ 𝑙 ) )
50 49 a1i ( 𝑗 = 𝑛 → ∏ 𝑘 ∈ { 𝐴 } ( vol ‘ ( ( [,) ∘ ( 𝑖𝑛 ) ) ‘ 𝑘 ) ) = ∏ 𝑙 ∈ { 𝐴 } ( vol ‘ ( ( [,) ∘ ( 𝑖𝑛 ) ) ‘ 𝑙 ) ) )
51 47 50 eqtrd ( 𝑗 = 𝑛 → ∏ 𝑘 ∈ { 𝐴 } ( vol ‘ ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) ) = ∏ 𝑙 ∈ { 𝐴 } ( vol ‘ ( ( [,) ∘ ( 𝑖𝑛 ) ) ‘ 𝑙 ) ) )
52 51 cbvmptv ( 𝑗 ∈ ℕ ↦ ∏ 𝑘 ∈ { 𝐴 } ( vol ‘ ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) ) ) = ( 𝑛 ∈ ℕ ↦ ∏ 𝑙 ∈ { 𝐴 } ( vol ‘ ( ( [,) ∘ ( 𝑖𝑛 ) ) ‘ 𝑙 ) ) )
53 52 fveq2i ( Σ^ ‘ ( 𝑗 ∈ ℕ ↦ ∏ 𝑘 ∈ { 𝐴 } ( vol ‘ ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) ) ) ) = ( Σ^ ‘ ( 𝑛 ∈ ℕ ↦ ∏ 𝑙 ∈ { 𝐴 } ( vol ‘ ( ( [,) ∘ ( 𝑖𝑛 ) ) ‘ 𝑙 ) ) ) )
54 53 eqeq2i ( 𝑧 = ( Σ^ ‘ ( 𝑗 ∈ ℕ ↦ ∏ 𝑘 ∈ { 𝐴 } ( vol ‘ ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) ) ) ) ↔ 𝑧 = ( Σ^ ‘ ( 𝑛 ∈ ℕ ↦ ∏ 𝑙 ∈ { 𝐴 } ( vol ‘ ( ( [,) ∘ ( 𝑖𝑛 ) ) ‘ 𝑙 ) ) ) ) )
55 54 biimpi ( 𝑧 = ( Σ^ ‘ ( 𝑗 ∈ ℕ ↦ ∏ 𝑘 ∈ { 𝐴 } ( vol ‘ ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) ) ) ) → 𝑧 = ( Σ^ ‘ ( 𝑛 ∈ ℕ ↦ ∏ 𝑙 ∈ { 𝐴 } ( vol ‘ ( ( [,) ∘ ( 𝑖𝑛 ) ) ‘ 𝑙 ) ) ) ) )
56 45 55 syl ( ( 𝜑𝑖 ∈ ( ( ( ℝ × ℝ ) ↑m { 𝐴 } ) ↑m ℕ ) ∧ ( ( 𝐵m { 𝐴 } ) ⊆ 𝑗 ∈ ℕ X 𝑘 ∈ { 𝐴 } ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) ∧ 𝑧 = ( Σ^ ‘ ( 𝑗 ∈ ℕ ↦ ∏ 𝑘 ∈ { 𝐴 } ( vol ‘ ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) ) ) ) ) ) → 𝑧 = ( Σ^ ‘ ( 𝑛 ∈ ℕ ↦ ∏ 𝑙 ∈ { 𝐴 } ( vol ‘ ( ( [,) ∘ ( 𝑖𝑛 ) ) ‘ 𝑙 ) ) ) ) )
57 fveq2 ( 𝑚 = 𝑛 → ( 𝑖𝑚 ) = ( 𝑖𝑛 ) )
58 57 fveq1d ( 𝑚 = 𝑛 → ( ( 𝑖𝑚 ) ‘ 𝐴 ) = ( ( 𝑖𝑛 ) ‘ 𝐴 ) )
59 58 cbvmptv ( 𝑚 ∈ ℕ ↦ ( ( 𝑖𝑚 ) ‘ 𝐴 ) ) = ( 𝑛 ∈ ℕ ↦ ( ( 𝑖𝑛 ) ‘ 𝐴 ) )
60 29 30 31 44 56 59 ovnovollem2 ( ( 𝜑𝑖 ∈ ( ( ( ℝ × ℝ ) ↑m { 𝐴 } ) ↑m ℕ ) ∧ ( ( 𝐵m { 𝐴 } ) ⊆ 𝑗 ∈ ℕ X 𝑘 ∈ { 𝐴 } ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) ∧ 𝑧 = ( Σ^ ‘ ( 𝑗 ∈ ℕ ↦ ∏ 𝑘 ∈ { 𝐴 } ( vol ‘ ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) ) ) ) ) ) → ∃ 𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) ( 𝐵 ran ( [,) ∘ 𝑓 ) ∧ 𝑧 = ( Σ^ ‘ ( ( vol ∘ [,) ) ∘ 𝑓 ) ) ) )
61 60 3exp ( 𝜑 → ( 𝑖 ∈ ( ( ( ℝ × ℝ ) ↑m { 𝐴 } ) ↑m ℕ ) → ( ( ( 𝐵m { 𝐴 } ) ⊆ 𝑗 ∈ ℕ X 𝑘 ∈ { 𝐴 } ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) ∧ 𝑧 = ( Σ^ ‘ ( 𝑗 ∈ ℕ ↦ ∏ 𝑘 ∈ { 𝐴 } ( vol ‘ ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) ) ) ) ) → ∃ 𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) ( 𝐵 ran ( [,) ∘ 𝑓 ) ∧ 𝑧 = ( Σ^ ‘ ( ( vol ∘ [,) ) ∘ 𝑓 ) ) ) ) ) )
62 61 rexlimdv ( 𝜑 → ( ∃ 𝑖 ∈ ( ( ( ℝ × ℝ ) ↑m { 𝐴 } ) ↑m ℕ ) ( ( 𝐵m { 𝐴 } ) ⊆ 𝑗 ∈ ℕ X 𝑘 ∈ { 𝐴 } ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) ∧ 𝑧 = ( Σ^ ‘ ( 𝑗 ∈ ℕ ↦ ∏ 𝑘 ∈ { 𝐴 } ( vol ‘ ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) ) ) ) ) → ∃ 𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) ( 𝐵 ran ( [,) ∘ 𝑓 ) ∧ 𝑧 = ( Σ^ ‘ ( ( vol ∘ [,) ) ∘ 𝑓 ) ) ) ) )
63 28 62 impbid ( 𝜑 → ( ∃ 𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) ( 𝐵 ran ( [,) ∘ 𝑓 ) ∧ 𝑧 = ( Σ^ ‘ ( ( vol ∘ [,) ) ∘ 𝑓 ) ) ) ↔ ∃ 𝑖 ∈ ( ( ( ℝ × ℝ ) ↑m { 𝐴 } ) ↑m ℕ ) ( ( 𝐵m { 𝐴 } ) ⊆ 𝑗 ∈ ℕ X 𝑘 ∈ { 𝐴 } ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) ∧ 𝑧 = ( Σ^ ‘ ( 𝑗 ∈ ℕ ↦ ∏ 𝑘 ∈ { 𝐴 } ( vol ‘ ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) ) ) ) ) ) )
64 63 rabbidv ( 𝜑 → { 𝑧 ∈ ℝ* ∣ ∃ 𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) ( 𝐵 ran ( [,) ∘ 𝑓 ) ∧ 𝑧 = ( Σ^ ‘ ( ( vol ∘ [,) ) ∘ 𝑓 ) ) ) } = { 𝑧 ∈ ℝ* ∣ ∃ 𝑖 ∈ ( ( ( ℝ × ℝ ) ↑m { 𝐴 } ) ↑m ℕ ) ( ( 𝐵m { 𝐴 } ) ⊆ 𝑗 ∈ ℕ X 𝑘 ∈ { 𝐴 } ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) ∧ 𝑧 = ( Σ^ ‘ ( 𝑗 ∈ ℕ ↦ ∏ 𝑘 ∈ { 𝐴 } ( vol ‘ ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) ) ) ) ) } )
65 4 a1i ( 𝜑𝑁 = { 𝑧 ∈ ℝ* ∣ ∃ 𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) ( 𝐵 ran ( [,) ∘ 𝑓 ) ∧ 𝑧 = ( Σ^ ‘ ( ( vol ∘ [,) ) ∘ 𝑓 ) ) ) } )
66 3 a1i ( 𝜑𝑀 = { 𝑧 ∈ ℝ* ∣ ∃ 𝑖 ∈ ( ( ( ℝ × ℝ ) ↑m { 𝐴 } ) ↑m ℕ ) ( ( 𝐵m { 𝐴 } ) ⊆ 𝑗 ∈ ℕ X 𝑘 ∈ { 𝐴 } ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) ∧ 𝑧 = ( Σ^ ‘ ( 𝑗 ∈ ℕ ↦ ∏ 𝑘 ∈ { 𝐴 } ( vol ‘ ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) ) ) ) ) } )
67 64 65 66 3eqtr4d ( 𝜑𝑁 = 𝑀 )
68 67 infeq1d ( 𝜑 → inf ( 𝑁 , ℝ* , < ) = inf ( 𝑀 , ℝ* , < ) )
69 15 68 eqtrd ( 𝜑 → ( vol* ‘ 𝐵 ) = inf ( 𝑀 , ℝ* , < ) )
70 7 14 69 3eqtr4d ( 𝜑 → ( ( voln* ‘ { 𝐴 } ) ‘ ( 𝐵m { 𝐴 } ) ) = ( vol* ‘ 𝐵 ) )