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 snnzg ( 𝐴𝑉 → { 𝐴 } ≠ ∅ )
6 1 5 syl ( 𝜑 → { 𝐴 } ≠ ∅ )
7 6 neneqd ( 𝜑 → ¬ { 𝐴 } = ∅ )
8 7 iffalsed ( 𝜑 → if ( { 𝐴 } = ∅ , 0 , inf ( 𝑀 , ℝ* , < ) ) = inf ( 𝑀 , ℝ* , < ) )
9 snfi { 𝐴 } ∈ Fin
10 9 a1i ( 𝜑 → { 𝐴 } ∈ Fin )
11 reex ℝ ∈ V
12 11 a1i ( 𝜑 → ℝ ∈ V )
13 mapss ( ( ℝ ∈ V ∧ 𝐵 ⊆ ℝ ) → ( 𝐵m { 𝐴 } ) ⊆ ( ℝ ↑m { 𝐴 } ) )
14 12 2 13 syl2anc ( 𝜑 → ( 𝐵m { 𝐴 } ) ⊆ ( ℝ ↑m { 𝐴 } ) )
15 10 14 3 ovnval2 ( 𝜑 → ( ( voln* ‘ { 𝐴 } ) ‘ ( 𝐵m { 𝐴 } ) ) = if ( { 𝐴 } = ∅ , 0 , inf ( 𝑀 , ℝ* , < ) ) )
16 2 4 ovolval5 ( 𝜑 → ( vol* ‘ 𝐵 ) = inf ( 𝑁 , ℝ* , < ) )
17 1 ad2antrr ( ( ( 𝜑𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) ) ∧ ( 𝐵 ran ( [,) ∘ 𝑓 ) ∧ 𝑧 = ( Σ^ ‘ ( ( vol ∘ [,) ) ∘ 𝑓 ) ) ) ) → 𝐴𝑉 )
18 simplr ( ( ( 𝜑𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) ) ∧ ( 𝐵 ran ( [,) ∘ 𝑓 ) ∧ 𝑧 = ( Σ^ ‘ ( ( vol ∘ [,) ) ∘ 𝑓 ) ) ) ) → 𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) )
19 fveq2 ( 𝑛 = 𝑗 → ( 𝑓𝑛 ) = ( 𝑓𝑗 ) )
20 19 opeq2d ( 𝑛 = 𝑗 → ⟨ 𝐴 , ( 𝑓𝑛 ) ⟩ = ⟨ 𝐴 , ( 𝑓𝑗 ) ⟩ )
21 20 sneqd ( 𝑛 = 𝑗 → { ⟨ 𝐴 , ( 𝑓𝑛 ) ⟩ } = { ⟨ 𝐴 , ( 𝑓𝑗 ) ⟩ } )
22 21 cbvmptv ( 𝑛 ∈ ℕ ↦ { ⟨ 𝐴 , ( 𝑓𝑛 ) ⟩ } ) = ( 𝑗 ∈ ℕ ↦ { ⟨ 𝐴 , ( 𝑓𝑗 ) ⟩ } )
23 simprl ( ( ( 𝜑𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) ) ∧ ( 𝐵 ran ( [,) ∘ 𝑓 ) ∧ 𝑧 = ( Σ^ ‘ ( ( vol ∘ [,) ) ∘ 𝑓 ) ) ) ) → 𝐵 ran ( [,) ∘ 𝑓 ) )
24 12 2 ssexd ( 𝜑𝐵 ∈ V )
25 24 adantr ( ( 𝜑𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) ) → 𝐵 ∈ V )
26 25 adantr ( ( ( 𝜑𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) ) ∧ ( 𝐵 ran ( [,) ∘ 𝑓 ) ∧ 𝑧 = ( Σ^ ‘ ( ( vol ∘ [,) ) ∘ 𝑓 ) ) ) ) → 𝐵 ∈ V )
27 simprr ( ( ( 𝜑𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) ) ∧ ( 𝐵 ran ( [,) ∘ 𝑓 ) ∧ 𝑧 = ( Σ^ ‘ ( ( vol ∘ [,) ) ∘ 𝑓 ) ) ) ) → 𝑧 = ( Σ^ ‘ ( ( vol ∘ [,) ) ∘ 𝑓 ) ) )
28 17 18 22 23 26 27 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 ) ) ) ) ) )
29 28 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 ) ) ) ) ) ) )
30 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 )
31 24 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 )
32 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 ) )
33 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 ) )
34 fveq2 ( 𝑗 = 𝑛 → ( 𝑖𝑗 ) = ( 𝑖𝑛 ) )
35 34 coeq2d ( 𝑗 = 𝑛 → ( [,) ∘ ( 𝑖𝑗 ) ) = ( [,) ∘ ( 𝑖𝑛 ) ) )
36 35 fveq1d ( 𝑗 = 𝑛 → ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) = ( ( [,) ∘ ( 𝑖𝑛 ) ) ‘ 𝑘 ) )
37 36 ixpeq2dv ( 𝑗 = 𝑛X 𝑘 ∈ { 𝐴 } ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) = X 𝑘 ∈ { 𝐴 } ( ( [,) ∘ ( 𝑖𝑛 ) ) ‘ 𝑘 ) )
38 fveq2 ( 𝑘 = 𝑙 → ( ( [,) ∘ ( 𝑖𝑛 ) ) ‘ 𝑘 ) = ( ( [,) ∘ ( 𝑖𝑛 ) ) ‘ 𝑙 ) )
39 38 cbvixpv X 𝑘 ∈ { 𝐴 } ( ( [,) ∘ ( 𝑖𝑛 ) ) ‘ 𝑘 ) = X 𝑙 ∈ { 𝐴 } ( ( [,) ∘ ( 𝑖𝑛 ) ) ‘ 𝑙 )
40 39 a1i ( 𝑗 = 𝑛X 𝑘 ∈ { 𝐴 } ( ( [,) ∘ ( 𝑖𝑛 ) ) ‘ 𝑘 ) = X 𝑙 ∈ { 𝐴 } ( ( [,) ∘ ( 𝑖𝑛 ) ) ‘ 𝑙 ) )
41 37 40 eqtrd ( 𝑗 = 𝑛X 𝑘 ∈ { 𝐴 } ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) = X 𝑙 ∈ { 𝐴 } ( ( [,) ∘ ( 𝑖𝑛 ) ) ‘ 𝑙 ) )
42 41 cbviunv 𝑗 ∈ ℕ X 𝑘 ∈ { 𝐴 } ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) = 𝑛 ∈ ℕ X 𝑙 ∈ { 𝐴 } ( ( [,) ∘ ( 𝑖𝑛 ) ) ‘ 𝑙 )
43 42 sseq2i ( ( 𝐵m { 𝐴 } ) ⊆ 𝑗 ∈ ℕ X 𝑘 ∈ { 𝐴 } ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) ↔ ( 𝐵m { 𝐴 } ) ⊆ 𝑛 ∈ ℕ X 𝑙 ∈ { 𝐴 } ( ( [,) ∘ ( 𝑖𝑛 ) ) ‘ 𝑙 ) )
44 43 biimpi ( ( 𝐵m { 𝐴 } ) ⊆ 𝑗 ∈ ℕ X 𝑘 ∈ { 𝐴 } ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) → ( 𝐵m { 𝐴 } ) ⊆ 𝑛 ∈ ℕ X 𝑙 ∈ { 𝐴 } ( ( [,) ∘ ( 𝑖𝑛 ) ) ‘ 𝑙 ) )
45 33 44 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 ) )
46 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 ) ) ) ) )
47 36 fveq2d ( 𝑗 = 𝑛 → ( vol ‘ ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) ) = ( vol ‘ ( ( [,) ∘ ( 𝑖𝑛 ) ) ‘ 𝑘 ) ) )
48 47 prodeq2ad ( 𝑗 = 𝑛 → ∏ 𝑘 ∈ { 𝐴 } ( vol ‘ ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) ) = ∏ 𝑘 ∈ { 𝐴 } ( vol ‘ ( ( [,) ∘ ( 𝑖𝑛 ) ) ‘ 𝑘 ) ) )
49 38 fveq2d ( 𝑘 = 𝑙 → ( vol ‘ ( ( [,) ∘ ( 𝑖𝑛 ) ) ‘ 𝑘 ) ) = ( vol ‘ ( ( [,) ∘ ( 𝑖𝑛 ) ) ‘ 𝑙 ) ) )
50 49 cbvprodv 𝑘 ∈ { 𝐴 } ( vol ‘ ( ( [,) ∘ ( 𝑖𝑛 ) ) ‘ 𝑘 ) ) = ∏ 𝑙 ∈ { 𝐴 } ( vol ‘ ( ( [,) ∘ ( 𝑖𝑛 ) ) ‘ 𝑙 ) )
51 50 a1i ( 𝑗 = 𝑛 → ∏ 𝑘 ∈ { 𝐴 } ( vol ‘ ( ( [,) ∘ ( 𝑖𝑛 ) ) ‘ 𝑘 ) ) = ∏ 𝑙 ∈ { 𝐴 } ( vol ‘ ( ( [,) ∘ ( 𝑖𝑛 ) ) ‘ 𝑙 ) ) )
52 48 51 eqtrd ( 𝑗 = 𝑛 → ∏ 𝑘 ∈ { 𝐴 } ( vol ‘ ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) ) = ∏ 𝑙 ∈ { 𝐴 } ( vol ‘ ( ( [,) ∘ ( 𝑖𝑛 ) ) ‘ 𝑙 ) ) )
53 52 cbvmptv ( 𝑗 ∈ ℕ ↦ ∏ 𝑘 ∈ { 𝐴 } ( vol ‘ ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) ) ) = ( 𝑛 ∈ ℕ ↦ ∏ 𝑙 ∈ { 𝐴 } ( vol ‘ ( ( [,) ∘ ( 𝑖𝑛 ) ) ‘ 𝑙 ) ) )
54 53 fveq2i ( Σ^ ‘ ( 𝑗 ∈ ℕ ↦ ∏ 𝑘 ∈ { 𝐴 } ( vol ‘ ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) ) ) ) = ( Σ^ ‘ ( 𝑛 ∈ ℕ ↦ ∏ 𝑙 ∈ { 𝐴 } ( vol ‘ ( ( [,) ∘ ( 𝑖𝑛 ) ) ‘ 𝑙 ) ) ) )
55 54 eqeq2i ( 𝑧 = ( Σ^ ‘ ( 𝑗 ∈ ℕ ↦ ∏ 𝑘 ∈ { 𝐴 } ( vol ‘ ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) ) ) ) ↔ 𝑧 = ( Σ^ ‘ ( 𝑛 ∈ ℕ ↦ ∏ 𝑙 ∈ { 𝐴 } ( vol ‘ ( ( [,) ∘ ( 𝑖𝑛 ) ) ‘ 𝑙 ) ) ) ) )
56 55 biimpi ( 𝑧 = ( Σ^ ‘ ( 𝑗 ∈ ℕ ↦ ∏ 𝑘 ∈ { 𝐴 } ( vol ‘ ( ( [,) ∘ ( 𝑖𝑗 ) ) ‘ 𝑘 ) ) ) ) → 𝑧 = ( Σ^ ‘ ( 𝑛 ∈ ℕ ↦ ∏ 𝑙 ∈ { 𝐴 } ( vol ‘ ( ( [,) ∘ ( 𝑖𝑛 ) ) ‘ 𝑙 ) ) ) ) )
57 46 56 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 ) ) ) ) )
58 fveq2 ( 𝑚 = 𝑛 → ( 𝑖𝑚 ) = ( 𝑖𝑛 ) )
59 58 fveq1d ( 𝑚 = 𝑛 → ( ( 𝑖𝑚 ) ‘ 𝐴 ) = ( ( 𝑖𝑛 ) ‘ 𝐴 ) )
60 59 cbvmptv ( 𝑚 ∈ ℕ ↦ ( ( 𝑖𝑚 ) ‘ 𝐴 ) ) = ( 𝑛 ∈ ℕ ↦ ( ( 𝑖𝑛 ) ‘ 𝐴 ) )
61 30 31 32 45 57 60 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 ) ) ) )
62 61 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 ) ) ) ) ) )
63 62 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 ) ) ) ) )
64 29 63 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 ) ) ) ) ) ) )
65 64 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 ) ) ) ) ) } )
66 4 a1i ( 𝜑𝑁 = { 𝑧 ∈ ℝ* ∣ ∃ 𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) ( 𝐵 ran ( [,) ∘ 𝑓 ) ∧ 𝑧 = ( Σ^ ‘ ( ( vol ∘ [,) ) ∘ 𝑓 ) ) ) } )
67 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 ) ) ) ) ) } )
68 65 66 67 3eqtr4d ( 𝜑𝑁 = 𝑀 )
69 68 infeq1d ( 𝜑 → inf ( 𝑁 , ℝ* , < ) = inf ( 𝑀 , ℝ* , < ) )
70 16 69 eqtrd ( 𝜑 → ( vol* ‘ 𝐵 ) = inf ( 𝑀 , ℝ* , < ) )
71 8 15 70 3eqtr4d ( 𝜑 → ( ( voln* ‘ { 𝐴 } ) ‘ ( 𝐵m { 𝐴 } ) ) = ( vol* ‘ 𝐵 ) )