Metamath Proof Explorer


Theorem itg2leub

Description: Any upper bound on the integrals of all simple functions G dominated by F is greater than ( S.2F ) , the least upper bound. (Contributed by Mario Carneiro, 28-Jun-2014)

Ref Expression
Assertion itg2leub ⊢ F : ℝ ⟶ 0 +∞ ∧ A ∈ ℝ * → ∫ 2 ⁡ F ≤ A ↔ ∀ g ∈ dom ⁡ ∫ 1 g ≤ f F → ∫ 1 ⁡ g ≤ A

Proof

Step Hyp Ref Expression
1 eqid ⊢ x | ∃ g ∈ dom ⁡ ∫ 1 g ≤ f F ∧ x = ∫ 1 ⁡ g = x | ∃ g ∈ dom ⁡ ∫ 1 g ≤ f F ∧ x = ∫ 1 ⁡ g
2 1 itg2val ⊢ F : ℝ ⟶ 0 +∞ → ∫ 2 ⁡ F = sup x | ∃ g ∈ dom ⁡ ∫ 1 g ≤ f F ∧ x = ∫ 1 ⁡ g ℝ * <
3 2 adantr ⊢ F : ℝ ⟶ 0 +∞ ∧ A ∈ ℝ * → ∫ 2 ⁡ F = sup x | ∃ g ∈ dom ⁡ ∫ 1 g ≤ f F ∧ x = ∫ 1 ⁡ g ℝ * <
4 3 breq1d ⊢ F : ℝ ⟶ 0 +∞ ∧ A ∈ ℝ * → ∫ 2 ⁡ F ≤ A ↔ sup x | ∃ g ∈ dom ⁡ ∫ 1 g ≤ f F ∧ x = ∫ 1 ⁡ g ℝ * < ≤ A
5 1 itg2lcl ⊢ x | ∃ g ∈ dom ⁡ ∫ 1 g ≤ f F ∧ x = ∫ 1 ⁡ g ⊆ ℝ *
6 supxrleub ⊢ x | ∃ g ∈ dom ⁡ ∫ 1 g ≤ f F ∧ x = ∫ 1 ⁡ g ⊆ ℝ * ∧ A ∈ ℝ * → sup x | ∃ g ∈ dom ⁡ ∫ 1 g ≤ f F ∧ x = ∫ 1 ⁡ g ℝ * < ≤ A ↔ ∀ z ∈ x | ∃ g ∈ dom ⁡ ∫ 1 g ≤ f F ∧ x = ∫ 1 ⁡ g z ≤ A
7 5 6 mpan ⊢ A ∈ ℝ * → sup x | ∃ g ∈ dom ⁡ ∫ 1 g ≤ f F ∧ x = ∫ 1 ⁡ g ℝ * < ≤ A ↔ ∀ z ∈ x | ∃ g ∈ dom ⁡ ∫ 1 g ≤ f F ∧ x = ∫ 1 ⁡ g z ≤ A
8 7 adantl ⊢ F : ℝ ⟶ 0 +∞ ∧ A ∈ ℝ * → sup x | ∃ g ∈ dom ⁡ ∫ 1 g ≤ f F ∧ x = ∫ 1 ⁡ g ℝ * < ≤ A ↔ ∀ z ∈ x | ∃ g ∈ dom ⁡ ∫ 1 g ≤ f F ∧ x = ∫ 1 ⁡ g z ≤ A
9 eqeq1 ⊢ x = z → x = ∫ 1 ⁡ g ↔ z = ∫ 1 ⁡ g
10 9 anbi2d ⊢ x = z → g ≤ f F ∧ x = ∫ 1 ⁡ g ↔ g ≤ f F ∧ z = ∫ 1 ⁡ g
11 10 rexbidv ⊢ x = z → ∃ g ∈ dom ⁡ ∫ 1 g ≤ f F ∧ x = ∫ 1 ⁡ g ↔ ∃ g ∈ dom ⁡ ∫ 1 g ≤ f F ∧ z = ∫ 1 ⁡ g
12 11 ralab ⊢ ∀ z ∈ x | ∃ g ∈ dom ⁡ ∫ 1 g ≤ f F ∧ x = ∫ 1 ⁡ g z ≤ A ↔ ∀ z ∃ g ∈ dom ⁡ ∫ 1 g ≤ f F ∧ z = ∫ 1 ⁡ g → z ≤ A
13 r19.23v ⊢ ∀ g ∈ dom ⁡ ∫ 1 g ≤ f F ∧ z = ∫ 1 ⁡ g → z ≤ A ↔ ∃ g ∈ dom ⁡ ∫ 1 g ≤ f F ∧ z = ∫ 1 ⁡ g → z ≤ A
14 ancomst ⊢ g ≤ f F ∧ z = ∫ 1 ⁡ g → z ≤ A ↔ z = ∫ 1 ⁡ g ∧ g ≤ f F → z ≤ A
15 impexp ⊢ z = ∫ 1 ⁡ g ∧ g ≤ f F → z ≤ A ↔ z = ∫ 1 ⁡ g → g ≤ f F → z ≤ A
16 14 15 bitri ⊢ g ≤ f F ∧ z = ∫ 1 ⁡ g → z ≤ A ↔ z = ∫ 1 ⁡ g → g ≤ f F → z ≤ A
17 16 ralbii ⊢ ∀ g ∈ dom ⁡ ∫ 1 g ≤ f F ∧ z = ∫ 1 ⁡ g → z ≤ A ↔ ∀ g ∈ dom ⁡ ∫ 1 z = ∫ 1 ⁡ g → g ≤ f F → z ≤ A
18 13 17 bitr3i ⊢ ∃ g ∈ dom ⁡ ∫ 1 g ≤ f F ∧ z = ∫ 1 ⁡ g → z ≤ A ↔ ∀ g ∈ dom ⁡ ∫ 1 z = ∫ 1 ⁡ g → g ≤ f F → z ≤ A
19 18 albii ⊢ ∀ z ∃ g ∈ dom ⁡ ∫ 1 g ≤ f F ∧ z = ∫ 1 ⁡ g → z ≤ A ↔ ∀ z ∀ g ∈ dom ⁡ ∫ 1 z = ∫ 1 ⁡ g → g ≤ f F → z ≤ A
20 ralcom4 ⊢ ∀ g ∈ dom ⁡ ∫ 1 ∀ z z = ∫ 1 ⁡ g → g ≤ f F → z ≤ A ↔ ∀ z ∀ g ∈ dom ⁡ ∫ 1 z = ∫ 1 ⁡ g → g ≤ f F → z ≤ A
21 fvex ⊢ ∫ 1 ⁡ g ∈ V
22 breq1 ⊢ z = ∫ 1 ⁡ g → z ≤ A ↔ ∫ 1 ⁡ g ≤ A
23 22 imbi2d ⊢ z = ∫ 1 ⁡ g → g ≤ f F → z ≤ A ↔ g ≤ f F → ∫ 1 ⁡ g ≤ A
24 21 23 ceqsalv ⊢ ∀ z z = ∫ 1 ⁡ g → g ≤ f F → z ≤ A ↔ g ≤ f F → ∫ 1 ⁡ g ≤ A
25 24 ralbii ⊢ ∀ g ∈ dom ⁡ ∫ 1 ∀ z z = ∫ 1 ⁡ g → g ≤ f F → z ≤ A ↔ ∀ g ∈ dom ⁡ ∫ 1 g ≤ f F → ∫ 1 ⁡ g ≤ A
26 20 25 bitr3i ⊢ ∀ z ∀ g ∈ dom ⁡ ∫ 1 z = ∫ 1 ⁡ g → g ≤ f F → z ≤ A ↔ ∀ g ∈ dom ⁡ ∫ 1 g ≤ f F → ∫ 1 ⁡ g ≤ A
27 19 26 bitri ⊢ ∀ z ∃ g ∈ dom ⁡ ∫ 1 g ≤ f F ∧ z = ∫ 1 ⁡ g → z ≤ A ↔ ∀ g ∈ dom ⁡ ∫ 1 g ≤ f F → ∫ 1 ⁡ g ≤ A
28 12 27 bitri ⊢ ∀ z ∈ x | ∃ g ∈ dom ⁡ ∫ 1 g ≤ f F ∧ x = ∫ 1 ⁡ g z ≤ A ↔ ∀ g ∈ dom ⁡ ∫ 1 g ≤ f F → ∫ 1 ⁡ g ≤ A
29 8 28 bitrdi ⊢ F : ℝ ⟶ 0 +∞ ∧ A ∈ ℝ * → sup x | ∃ g ∈ dom ⁡ ∫ 1 g ≤ f F ∧ x = ∫ 1 ⁡ g ℝ * < ≤ A ↔ ∀ g ∈ dom ⁡ ∫ 1 g ≤ f F → ∫ 1 ⁡ g ≤ A
30 4 29 bitrd ⊢ F : ℝ ⟶ 0 +∞ ∧ A ∈ ℝ * → ∫ 2 ⁡ F ≤ A ↔ ∀ g ∈ dom ⁡ ∫ 1 g ≤ f F → ∫ 1 ⁡ g ≤ A