Metamath Proof Explorer


Theorem ovolval4lem2

Description: The value of the Lebesgue outer measure for subsets of the reals. Similar to ovolval3 , but here f is may represent unordered interval bounds. (Contributed by Glauco Siliprandi, 3-Mar-2021)

Ref Expression
Hypotheses ovolval4lem2.a ⊢ ( 𝜑 → 𝐴 ⊆ ℝ )
ovolval4lem2.m ⊢ 𝑀 = { 𝑦 ∈ ℝ* ∣ ∃ 𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) ( 𝐴 ⊆ ∪ ran ( (,) ∘ 𝑓 ) ∧ 𝑦 = ( Σ^ ‘ ( ( vol ∘ (,) ) ∘ 𝑓 ) ) ) }
ovolval4lem2.g ⊢ 𝐺 = ( 𝑛 ∈ ℕ ↦ ⟨ ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) , if ( ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) ≤ ( 2nd ‘ ( 𝑓 ‘ 𝑛 ) ) , ( 2nd ‘ ( 𝑓 ‘ 𝑛 ) ) , ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) ) ⟩ )
Assertion ovolval4lem2 ( 𝜑 → ( vol* ‘ 𝐴 ) = inf ( 𝑀 , ℝ* , < ) )

Proof

Step Hyp Ref Expression
1 ovolval4lem2.a ⊢ ( 𝜑 → 𝐴 ⊆ ℝ )
2 ovolval4lem2.m ⊢ 𝑀 = { 𝑦 ∈ ℝ* ∣ ∃ 𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) ( 𝐴 ⊆ ∪ ran ( (,) ∘ 𝑓 ) ∧ 𝑦 = ( Σ^ ‘ ( ( vol ∘ (,) ) ∘ 𝑓 ) ) ) }
3 ovolval4lem2.g ⊢ 𝐺 = ( 𝑛 ∈ ℕ ↦ ⟨ ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) , if ( ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) ≤ ( 2nd ‘ ( 𝑓 ‘ 𝑛 ) ) , ( 2nd ‘ ( 𝑓 ‘ 𝑛 ) ) , ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) ) ⟩ )
4 iftrue ⊢ ( ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) ≤ ( 2nd ‘ ( 𝑓 ‘ 𝑛 ) ) → if ( ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) ≤ ( 2nd ‘ ( 𝑓 ‘ 𝑛 ) ) , ( 2nd ‘ ( 𝑓 ‘ 𝑛 ) ) , ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) ) = ( 2nd ‘ ( 𝑓 ‘ 𝑛 ) ) )
5 4 opeq2d ⊢ ( ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) ≤ ( 2nd ‘ ( 𝑓 ‘ 𝑛 ) ) → ⟨ ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) , if ( ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) ≤ ( 2nd ‘ ( 𝑓 ‘ 𝑛 ) ) , ( 2nd ‘ ( 𝑓 ‘ 𝑛 ) ) , ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) ) ⟩ = ⟨ ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) , ( 2nd ‘ ( 𝑓 ‘ 𝑛 ) ) ⟩ )
6 5 adantl ⊢ ( ( ( 𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) ∧ 𝑛 ∈ ℕ ) ∧ ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) ≤ ( 2nd ‘ ( 𝑓 ‘ 𝑛 ) ) ) → ⟨ ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) , if ( ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) ≤ ( 2nd ‘ ( 𝑓 ‘ 𝑛 ) ) , ( 2nd ‘ ( 𝑓 ‘ 𝑛 ) ) , ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) ) ⟩ = ⟨ ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) , ( 2nd ‘ ( 𝑓 ‘ 𝑛 ) ) ⟩ )
7 df-br ⊢ ( ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) ≤ ( 2nd ‘ ( 𝑓 ‘ 𝑛 ) ) ↔ ⟨ ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) , ( 2nd ‘ ( 𝑓 ‘ 𝑛 ) ) ⟩ ∈ ≤ )
8 7 bilani ⊢ ( ( ( 𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) ∧ 𝑛 ∈ ℕ ) ∧ ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) ≤ ( 2nd ‘ ( 𝑓 ‘ 𝑛 ) ) ) → ⟨ ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) , ( 2nd ‘ ( 𝑓 ‘ 𝑛 ) ) ⟩ ∈ ≤ )
9 6 8 eqeltrd ⊢ ( ( ( 𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) ∧ 𝑛 ∈ ℕ ) ∧ ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) ≤ ( 2nd ‘ ( 𝑓 ‘ 𝑛 ) ) ) → ⟨ ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) , if ( ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) ≤ ( 2nd ‘ ( 𝑓 ‘ 𝑛 ) ) , ( 2nd ‘ ( 𝑓 ‘ 𝑛 ) ) , ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) ) ⟩ ∈ ≤ )
10 iffalse ⊢ ( ¬ ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) ≤ ( 2nd ‘ ( 𝑓 ‘ 𝑛 ) ) → if ( ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) ≤ ( 2nd ‘ ( 𝑓 ‘ 𝑛 ) ) , ( 2nd ‘ ( 𝑓 ‘ 𝑛 ) ) , ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) ) = ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) )
11 10 opeq2d ⊢ ( ¬ ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) ≤ ( 2nd ‘ ( 𝑓 ‘ 𝑛 ) ) → ⟨ ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) , if ( ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) ≤ ( 2nd ‘ ( 𝑓 ‘ 𝑛 ) ) , ( 2nd ‘ ( 𝑓 ‘ 𝑛 ) ) , ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) ) ⟩ = ⟨ ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) , ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) ⟩ )
12 11 adantl ⊢ ( ( ( 𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) ∧ 𝑛 ∈ ℕ ) ∧ ¬ ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) ≤ ( 2nd ‘ ( 𝑓 ‘ 𝑛 ) ) ) → ⟨ ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) , if ( ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) ≤ ( 2nd ‘ ( 𝑓 ‘ 𝑛 ) ) , ( 2nd ‘ ( 𝑓 ‘ 𝑛 ) ) , ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) ) ⟩ = ⟨ ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) , ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) ⟩ )
13 elmapi ⊢ ( 𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) → 𝑓 : ℕ ⟶ ( ℝ × ℝ ) )
14 13 ffvelcdmda ⊢ ( ( 𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) ∧ 𝑛 ∈ ℕ ) → ( 𝑓 ‘ 𝑛 ) ∈ ( ℝ × ℝ ) )
15 xp1st ⊢ ( ( 𝑓 ‘ 𝑛 ) ∈ ( ℝ × ℝ ) → ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) ∈ ℝ )
16 14 15 syl ⊢ ( ( 𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) ∧ 𝑛 ∈ ℕ ) → ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) ∈ ℝ )
17 16 leidd ⊢ ( ( 𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) ∧ 𝑛 ∈ ℕ ) → ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) ≤ ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) )
18 df-br ⊢ ( ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) ≤ ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) ↔ ⟨ ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) , ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) ⟩ ∈ ≤ )
19 17 18 sylib ⊢ ( ( 𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) ∧ 𝑛 ∈ ℕ ) → ⟨ ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) , ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) ⟩ ∈ ≤ )
20 19 adantr ⊢ ( ( ( 𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) ∧ 𝑛 ∈ ℕ ) ∧ ¬ ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) ≤ ( 2nd ‘ ( 𝑓 ‘ 𝑛 ) ) ) → ⟨ ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) , ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) ⟩ ∈ ≤ )
21 12 20 eqeltrd ⊢ ( ( ( 𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) ∧ 𝑛 ∈ ℕ ) ∧ ¬ ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) ≤ ( 2nd ‘ ( 𝑓 ‘ 𝑛 ) ) ) → ⟨ ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) , if ( ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) ≤ ( 2nd ‘ ( 𝑓 ‘ 𝑛 ) ) , ( 2nd ‘ ( 𝑓 ‘ 𝑛 ) ) , ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) ) ⟩ ∈ ≤ )
22 9 21 pm2.61dan ⊢ ( ( 𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) ∧ 𝑛 ∈ ℕ ) → ⟨ ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) , if ( ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) ≤ ( 2nd ‘ ( 𝑓 ‘ 𝑛 ) ) , ( 2nd ‘ ( 𝑓 ‘ 𝑛 ) ) , ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) ) ⟩ ∈ ≤ )
23 xp2nd ⊢ ( ( 𝑓 ‘ 𝑛 ) ∈ ( ℝ × ℝ ) → ( 2nd ‘ ( 𝑓 ‘ 𝑛 ) ) ∈ ℝ )
24 14 23 syl ⊢ ( ( 𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) ∧ 𝑛 ∈ ℕ ) → ( 2nd ‘ ( 𝑓 ‘ 𝑛 ) ) ∈ ℝ )
25 24 16 ifcld ⊢ ( ( 𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) ∧ 𝑛 ∈ ℕ ) → if ( ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) ≤ ( 2nd ‘ ( 𝑓 ‘ 𝑛 ) ) , ( 2nd ‘ ( 𝑓 ‘ 𝑛 ) ) , ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) ) ∈ ℝ )
26 opelxpi ⊢ ( ( ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) ∈ ℝ ∧ if ( ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) ≤ ( 2nd ‘ ( 𝑓 ‘ 𝑛 ) ) , ( 2nd ‘ ( 𝑓 ‘ 𝑛 ) ) , ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) ) ∈ ℝ ) → ⟨ ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) , if ( ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) ≤ ( 2nd ‘ ( 𝑓 ‘ 𝑛 ) ) , ( 2nd ‘ ( 𝑓 ‘ 𝑛 ) ) , ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) ) ⟩ ∈ ( ℝ × ℝ ) )
27 16 25 26 syl2anc ⊢ ( ( 𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) ∧ 𝑛 ∈ ℕ ) → ⟨ ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) , if ( ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) ≤ ( 2nd ‘ ( 𝑓 ‘ 𝑛 ) ) , ( 2nd ‘ ( 𝑓 ‘ 𝑛 ) ) , ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) ) ⟩ ∈ ( ℝ × ℝ ) )
28 22 27 elind ⊢ ( ( 𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) ∧ 𝑛 ∈ ℕ ) → ⟨ ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) , if ( ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) ≤ ( 2nd ‘ ( 𝑓 ‘ 𝑛 ) ) , ( 2nd ‘ ( 𝑓 ‘ 𝑛 ) ) , ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) ) ⟩ ∈ ( ≤ ∩ ( ℝ × ℝ ) ) )
29 28 3 fmptd ⊢ ( 𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) → 𝐺 : ℕ ⟶ ( ≤ ∩ ( ℝ × ℝ ) ) )
30 reex ⊢ ℝ ∈ V
31 30 30 xpex ⊢ ( ℝ × ℝ ) ∈ V
32 31 inex2 ⊢ ( ≤ ∩ ( ℝ × ℝ ) ) ∈ V
33 32 a1i ⊢ ( 𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) → ( ≤ ∩ ( ℝ × ℝ ) ) ∈ V )
34 nnex ⊢ ℕ ∈ V
35 34 a1i ⊢ ( 𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) → ℕ ∈ V )
36 33 35 elmapd ⊢ ( 𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) → ( 𝐺 ∈ ( ( ≤ ∩ ( ℝ × ℝ ) ) ↑m ℕ ) ↔ 𝐺 : ℕ ⟶ ( ≤ ∩ ( ℝ × ℝ ) ) ) )
37 29 36 mpbird ⊢ ( 𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) → 𝐺 ∈ ( ( ≤ ∩ ( ℝ × ℝ ) ) ↑m ℕ ) )
38 37 adantr ⊢ ( ( 𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) ∧ ( 𝐴 ⊆ ∪ ran ( (,) ∘ 𝑓 ) ∧ 𝑦 = ( Σ^ ‘ ( ( vol ∘ (,) ) ∘ 𝑓 ) ) ) ) → 𝐺 ∈ ( ( ≤ ∩ ( ℝ × ℝ ) ) ↑m ℕ ) )
39 simpr ⊢ ( ( 𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) ∧ 𝐴 ⊆ ∪ ran ( (,) ∘ 𝑓 ) ) → 𝐴 ⊆ ∪ ran ( (,) ∘ 𝑓 ) )
40 rexpssxrxp ⊢ ( ℝ × ℝ ) ⊆ ( ℝ* × ℝ* )
41 40 a1i ⊢ ( 𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) → ( ℝ × ℝ ) ⊆ ( ℝ* × ℝ* ) )
42 13 41 fssd ⊢ ( 𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) → 𝑓 : ℕ ⟶ ( ℝ* × ℝ* ) )
43 2fveq3 ⊢ ( 𝑘 = 𝑛 → ( 1st ‘ ( 𝑓 ‘ 𝑘 ) ) = ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) )
44 2fveq3 ⊢ ( 𝑘 = 𝑛 → ( 2nd ‘ ( 𝑓 ‘ 𝑘 ) ) = ( 2nd ‘ ( 𝑓 ‘ 𝑛 ) ) )
45 43 44 breq12d ⊢ ( 𝑘 = 𝑛 → ( ( 1st ‘ ( 𝑓 ‘ 𝑘 ) ) ≤ ( 2nd ‘ ( 𝑓 ‘ 𝑘 ) ) ↔ ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) ≤ ( 2nd ‘ ( 𝑓 ‘ 𝑛 ) ) ) )
46 45 cbvrabv ⊢ { 𝑘 ∈ ℕ ∣ ( 1st ‘ ( 𝑓 ‘ 𝑘 ) ) ≤ ( 2nd ‘ ( 𝑓 ‘ 𝑘 ) ) } = { 𝑛 ∈ ℕ ∣ ( 1st ‘ ( 𝑓 ‘ 𝑛 ) ) ≤ ( 2nd ‘ ( 𝑓 ‘ 𝑛 ) ) }
47 42 3 46 ovolval4lem1 ⊢ ( 𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) → ( ∪ ran ( (,) ∘ 𝑓 ) = ∪ ran ( (,) ∘ 𝐺 ) ∧ ( vol ∘ ( (,) ∘ 𝑓 ) ) = ( vol ∘ ( (,) ∘ 𝐺 ) ) ) )
48 47 simpld ⊢ ( 𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) → ∪ ran ( (,) ∘ 𝑓 ) = ∪ ran ( (,) ∘ 𝐺 ) )
49 48 adantr ⊢ ( ( 𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) ∧ 𝐴 ⊆ ∪ ran ( (,) ∘ 𝑓 ) ) → ∪ ran ( (,) ∘ 𝑓 ) = ∪ ran ( (,) ∘ 𝐺 ) )
50 39 49 sseqtrd ⊢ ( ( 𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) ∧ 𝐴 ⊆ ∪ ran ( (,) ∘ 𝑓 ) ) → 𝐴 ⊆ ∪ ran ( (,) ∘ 𝐺 ) )
51 50 adantrr ⊢ ( ( 𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) ∧ ( 𝐴 ⊆ ∪ ran ( (,) ∘ 𝑓 ) ∧ 𝑦 = ( Σ^ ‘ ( ( vol ∘ (,) ) ∘ 𝑓 ) ) ) ) → 𝐴 ⊆ ∪ ran ( (,) ∘ 𝐺 ) )
52 simpr ⊢ ( ( 𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) ∧ 𝑦 = ( Σ^ ‘ ( ( vol ∘ (,) ) ∘ 𝑓 ) ) ) → 𝑦 = ( Σ^ ‘ ( ( vol ∘ (,) ) ∘ 𝑓 ) ) )
53 47 simprd ⊢ ( 𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) → ( vol ∘ ( (,) ∘ 𝑓 ) ) = ( vol ∘ ( (,) ∘ 𝐺 ) ) )
54 coass ⊢ ( ( vol ∘ (,) ) ∘ 𝑓 ) = ( vol ∘ ( (,) ∘ 𝑓 ) )
55 54 a1i ⊢ ( 𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) → ( ( vol ∘ (,) ) ∘ 𝑓 ) = ( vol ∘ ( (,) ∘ 𝑓 ) ) )
56 coass ⊢ ( ( vol ∘ (,) ) ∘ 𝐺 ) = ( vol ∘ ( (,) ∘ 𝐺 ) )
57 56 a1i ⊢ ( 𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) → ( ( vol ∘ (,) ) ∘ 𝐺 ) = ( vol ∘ ( (,) ∘ 𝐺 ) ) )
58 53 55 57 3eqtr4d ⊢ ( 𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) → ( ( vol ∘ (,) ) ∘ 𝑓 ) = ( ( vol ∘ (,) ) ∘ 𝐺 ) )
59 58 fveq2d ⊢ ( 𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) → ( Σ^ ‘ ( ( vol ∘ (,) ) ∘ 𝑓 ) ) = ( Σ^ ‘ ( ( vol ∘ (,) ) ∘ 𝐺 ) ) )
60 59 adantr ⊢ ( ( 𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) ∧ 𝑦 = ( Σ^ ‘ ( ( vol ∘ (,) ) ∘ 𝑓 ) ) ) → ( Σ^ ‘ ( ( vol ∘ (,) ) ∘ 𝑓 ) ) = ( Σ^ ‘ ( ( vol ∘ (,) ) ∘ 𝐺 ) ) )
61 52 60 eqtrd ⊢ ( ( 𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) ∧ 𝑦 = ( Σ^ ‘ ( ( vol ∘ (,) ) ∘ 𝑓 ) ) ) → 𝑦 = ( Σ^ ‘ ( ( vol ∘ (,) ) ∘ 𝐺 ) ) )
62 61 adantrl ⊢ ( ( 𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) ∧ ( 𝐴 ⊆ ∪ ran ( (,) ∘ 𝑓 ) ∧ 𝑦 = ( Σ^ ‘ ( ( vol ∘ (,) ) ∘ 𝑓 ) ) ) ) → 𝑦 = ( Σ^ ‘ ( ( vol ∘ (,) ) ∘ 𝐺 ) ) )
63 51 62 jca ⊢ ( ( 𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) ∧ ( 𝐴 ⊆ ∪ ran ( (,) ∘ 𝑓 ) ∧ 𝑦 = ( Σ^ ‘ ( ( vol ∘ (,) ) ∘ 𝑓 ) ) ) ) → ( 𝐴 ⊆ ∪ ran ( (,) ∘ 𝐺 ) ∧ 𝑦 = ( Σ^ ‘ ( ( vol ∘ (,) ) ∘ 𝐺 ) ) ) )
64 coeq2 ⊢ ( 𝑔 = 𝐺 → ( (,) ∘ 𝑔 ) = ( (,) ∘ 𝐺 ) )
65 64 rneqd ⊢ ( 𝑔 = 𝐺 → ran ( (,) ∘ 𝑔 ) = ran ( (,) ∘ 𝐺 ) )
66 65 unieqd ⊢ ( 𝑔 = 𝐺 → ∪ ran ( (,) ∘ 𝑔 ) = ∪ ran ( (,) ∘ 𝐺 ) )
67 66 sseq2d ⊢ ( 𝑔 = 𝐺 → ( 𝐴 ⊆ ∪ ran ( (,) ∘ 𝑔 ) ↔ 𝐴 ⊆ ∪ ran ( (,) ∘ 𝐺 ) ) )
68 coeq2 ⊢ ( 𝑔 = 𝐺 → ( ( vol ∘ (,) ) ∘ 𝑔 ) = ( ( vol ∘ (,) ) ∘ 𝐺 ) )
69 68 fveq2d ⊢ ( 𝑔 = 𝐺 → ( Σ^ ‘ ( ( vol ∘ (,) ) ∘ 𝑔 ) ) = ( Σ^ ‘ ( ( vol ∘ (,) ) ∘ 𝐺 ) ) )
70 69 eqeq2d ⊢ ( 𝑔 = 𝐺 → ( 𝑦 = ( Σ^ ‘ ( ( vol ∘ (,) ) ∘ 𝑔 ) ) ↔ 𝑦 = ( Σ^ ‘ ( ( vol ∘ (,) ) ∘ 𝐺 ) ) ) )
71 67 70 anbi12d ⊢ ( 𝑔 = 𝐺 → ( ( 𝐴 ⊆ ∪ ran ( (,) ∘ 𝑔 ) ∧ 𝑦 = ( Σ^ ‘ ( ( vol ∘ (,) ) ∘ 𝑔 ) ) ) ↔ ( 𝐴 ⊆ ∪ ran ( (,) ∘ 𝐺 ) ∧ 𝑦 = ( Σ^ ‘ ( ( vol ∘ (,) ) ∘ 𝐺 ) ) ) ) )
72 71 rspcev ⊢ ( ( 𝐺 ∈ ( ( ≤ ∩ ( ℝ × ℝ ) ) ↑m ℕ ) ∧ ( 𝐴 ⊆ ∪ ran ( (,) ∘ 𝐺 ) ∧ 𝑦 = ( Σ^ ‘ ( ( vol ∘ (,) ) ∘ 𝐺 ) ) ) ) → ∃ 𝑔 ∈ ( ( ≤ ∩ ( ℝ × ℝ ) ) ↑m ℕ ) ( 𝐴 ⊆ ∪ ran ( (,) ∘ 𝑔 ) ∧ 𝑦 = ( Σ^ ‘ ( ( vol ∘ (,) ) ∘ 𝑔 ) ) ) )
73 38 63 72 syl2anc ⊢ ( ( 𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) ∧ ( 𝐴 ⊆ ∪ ran ( (,) ∘ 𝑓 ) ∧ 𝑦 = ( Σ^ ‘ ( ( vol ∘ (,) ) ∘ 𝑓 ) ) ) ) → ∃ 𝑔 ∈ ( ( ≤ ∩ ( ℝ × ℝ ) ) ↑m ℕ ) ( 𝐴 ⊆ ∪ ran ( (,) ∘ 𝑔 ) ∧ 𝑦 = ( Σ^ ‘ ( ( vol ∘ (,) ) ∘ 𝑔 ) ) ) )
74 73 rexlimiva ⊢ ( ∃ 𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) ( 𝐴 ⊆ ∪ ran ( (,) ∘ 𝑓 ) ∧ 𝑦 = ( Σ^ ‘ ( ( vol ∘ (,) ) ∘ 𝑓 ) ) ) → ∃ 𝑔 ∈ ( ( ≤ ∩ ( ℝ × ℝ ) ) ↑m ℕ ) ( 𝐴 ⊆ ∪ ran ( (,) ∘ 𝑔 ) ∧ 𝑦 = ( Σ^ ‘ ( ( vol ∘ (,) ) ∘ 𝑔 ) ) ) )
75 inss2 ⊢ ( ≤ ∩ ( ℝ × ℝ ) ) ⊆ ( ℝ × ℝ )
76 mapss ⊢ ( ( ( ℝ × ℝ ) ∈ V ∧ ( ≤ ∩ ( ℝ × ℝ ) ) ⊆ ( ℝ × ℝ ) ) → ( ( ≤ ∩ ( ℝ × ℝ ) ) ↑m ℕ ) ⊆ ( ( ℝ × ℝ ) ↑m ℕ ) )
77 31 75 76 mp2an ⊢ ( ( ≤ ∩ ( ℝ × ℝ ) ) ↑m ℕ ) ⊆ ( ( ℝ × ℝ ) ↑m ℕ )
78 77 sseli ⊢ ( 𝑔 ∈ ( ( ≤ ∩ ( ℝ × ℝ ) ) ↑m ℕ ) → 𝑔 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) )
79 78 adantr ⊢ ( ( 𝑔 ∈ ( ( ≤ ∩ ( ℝ × ℝ ) ) ↑m ℕ ) ∧ ( 𝐴 ⊆ ∪ ran ( (,) ∘ 𝑔 ) ∧ 𝑦 = ( Σ^ ‘ ( ( vol ∘ (,) ) ∘ 𝑔 ) ) ) ) → 𝑔 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) )
80 simpr ⊢ ( ( 𝑔 ∈ ( ( ≤ ∩ ( ℝ × ℝ ) ) ↑m ℕ ) ∧ ( 𝐴 ⊆ ∪ ran ( (,) ∘ 𝑔 ) ∧ 𝑦 = ( Σ^ ‘ ( ( vol ∘ (,) ) ∘ 𝑔 ) ) ) ) → ( 𝐴 ⊆ ∪ ran ( (,) ∘ 𝑔 ) ∧ 𝑦 = ( Σ^ ‘ ( ( vol ∘ (,) ) ∘ 𝑔 ) ) ) )
81 coeq2 ⊢ ( 𝑓 = 𝑔 → ( (,) ∘ 𝑓 ) = ( (,) ∘ 𝑔 ) )
82 81 rneqd ⊢ ( 𝑓 = 𝑔 → ran ( (,) ∘ 𝑓 ) = ran ( (,) ∘ 𝑔 ) )
83 82 unieqd ⊢ ( 𝑓 = 𝑔 → ∪ ran ( (,) ∘ 𝑓 ) = ∪ ran ( (,) ∘ 𝑔 ) )
84 83 sseq2d ⊢ ( 𝑓 = 𝑔 → ( 𝐴 ⊆ ∪ ran ( (,) ∘ 𝑓 ) ↔ 𝐴 ⊆ ∪ ran ( (,) ∘ 𝑔 ) ) )
85 coeq2 ⊢ ( 𝑓 = 𝑔 → ( ( vol ∘ (,) ) ∘ 𝑓 ) = ( ( vol ∘ (,) ) ∘ 𝑔 ) )
86 85 fveq2d ⊢ ( 𝑓 = 𝑔 → ( Σ^ ‘ ( ( vol ∘ (,) ) ∘ 𝑓 ) ) = ( Σ^ ‘ ( ( vol ∘ (,) ) ∘ 𝑔 ) ) )
87 86 eqeq2d ⊢ ( 𝑓 = 𝑔 → ( 𝑦 = ( Σ^ ‘ ( ( vol ∘ (,) ) ∘ 𝑓 ) ) ↔ 𝑦 = ( Σ^ ‘ ( ( vol ∘ (,) ) ∘ 𝑔 ) ) ) )
88 84 87 anbi12d ⊢ ( 𝑓 = 𝑔 → ( ( 𝐴 ⊆ ∪ ran ( (,) ∘ 𝑓 ) ∧ 𝑦 = ( Σ^ ‘ ( ( vol ∘ (,) ) ∘ 𝑓 ) ) ) ↔ ( 𝐴 ⊆ ∪ ran ( (,) ∘ 𝑔 ) ∧ 𝑦 = ( Σ^ ‘ ( ( vol ∘ (,) ) ∘ 𝑔 ) ) ) ) )
89 88 rspcev ⊢ ( ( 𝑔 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) ∧ ( 𝐴 ⊆ ∪ ran ( (,) ∘ 𝑔 ) ∧ 𝑦 = ( Σ^ ‘ ( ( vol ∘ (,) ) ∘ 𝑔 ) ) ) ) → ∃ 𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) ( 𝐴 ⊆ ∪ ran ( (,) ∘ 𝑓 ) ∧ 𝑦 = ( Σ^ ‘ ( ( vol ∘ (,) ) ∘ 𝑓 ) ) ) )
90 79 80 89 syl2anc ⊢ ( ( 𝑔 ∈ ( ( ≤ ∩ ( ℝ × ℝ ) ) ↑m ℕ ) ∧ ( 𝐴 ⊆ ∪ ran ( (,) ∘ 𝑔 ) ∧ 𝑦 = ( Σ^ ‘ ( ( vol ∘ (,) ) ∘ 𝑔 ) ) ) ) → ∃ 𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) ( 𝐴 ⊆ ∪ ran ( (,) ∘ 𝑓 ) ∧ 𝑦 = ( Σ^ ‘ ( ( vol ∘ (,) ) ∘ 𝑓 ) ) ) )
91 90 rexlimiva ⊢ ( ∃ 𝑔 ∈ ( ( ≤ ∩ ( ℝ × ℝ ) ) ↑m ℕ ) ( 𝐴 ⊆ ∪ ran ( (,) ∘ 𝑔 ) ∧ 𝑦 = ( Σ^ ‘ ( ( vol ∘ (,) ) ∘ 𝑔 ) ) ) → ∃ 𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) ( 𝐴 ⊆ ∪ ran ( (,) ∘ 𝑓 ) ∧ 𝑦 = ( Σ^ ‘ ( ( vol ∘ (,) ) ∘ 𝑓 ) ) ) )
92 74 91 impbii ⊢ ( ∃ 𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) ( 𝐴 ⊆ ∪ ran ( (,) ∘ 𝑓 ) ∧ 𝑦 = ( Σ^ ‘ ( ( vol ∘ (,) ) ∘ 𝑓 ) ) ) ↔ ∃ 𝑔 ∈ ( ( ≤ ∩ ( ℝ × ℝ ) ) ↑m ℕ ) ( 𝐴 ⊆ ∪ ran ( (,) ∘ 𝑔 ) ∧ 𝑦 = ( Σ^ ‘ ( ( vol ∘ (,) ) ∘ 𝑔 ) ) ) )
93 92 rabbii ⊢ { 𝑦 ∈ ℝ* ∣ ∃ 𝑓 ∈ ( ( ℝ × ℝ ) ↑m ℕ ) ( 𝐴 ⊆ ∪ ran ( (,) ∘ 𝑓 ) ∧ 𝑦 = ( Σ^ ‘ ( ( vol ∘ (,) ) ∘ 𝑓 ) ) ) } = { 𝑦 ∈ ℝ* ∣ ∃ 𝑔 ∈ ( ( ≤ ∩ ( ℝ × ℝ ) ) ↑m ℕ ) ( 𝐴 ⊆ ∪ ran ( (,) ∘ 𝑔 ) ∧ 𝑦 = ( Σ^ ‘ ( ( vol ∘ (,) ) ∘ 𝑔 ) ) ) }
94 2 93 eqtri ⊢ 𝑀 = { 𝑦 ∈ ℝ* ∣ ∃ 𝑔 ∈ ( ( ≤ ∩ ( ℝ × ℝ ) ) ↑m ℕ ) ( 𝐴 ⊆ ∪ ran ( (,) ∘ 𝑔 ) ∧ 𝑦 = ( Σ^ ‘ ( ( vol ∘ (,) ) ∘ 𝑔 ) ) ) }
95 1 94 ovolval3 ⊢ ( 𝜑 → ( vol* ‘ 𝐴 ) = inf ( 𝑀 , ℝ* , < ) )