Metamath Proof Explorer


Theorem smfpimioompt

Description: Given a function measurable w.r.t. to a sigma-algebra, the preimage of an open interval is in the subspace sigma-algebra induced by its domain. (Contributed by Glauco Siliprandi, 26-Jun-2021)

Ref Expression
Hypotheses smfpimioompt.x ⊢ Ⅎ x φ
smfpimioompt.s ⊢ φ → S ∈ SAlg
smfpimioompt.a ⊢ φ → A ∈ V
smfpimioompt.b ⊢ φ ∧ x ∈ A → B ∈ W
smfpimioompt.m ⊢ φ → x ∈ A ⟼ B ∈ SMblFn ⁡ S
smfpimioompt.l ⊢ φ → L ∈ ℝ *
smfpimioompt.r ⊢ φ → R ∈ ℝ *
Assertion smfpimioompt ⊢ φ → x ∈ A | B ∈ L R ∈ S ↾ 𝑡 A

Proof

Step Hyp Ref Expression
1 smfpimioompt.x ⊢ Ⅎ x φ
2 smfpimioompt.s ⊢ φ → S ∈ SAlg
3 smfpimioompt.a ⊢ φ → A ∈ V
4 smfpimioompt.b ⊢ φ ∧ x ∈ A → B ∈ W
5 smfpimioompt.m ⊢ φ → x ∈ A ⟼ B ∈ SMblFn ⁡ S
6 smfpimioompt.l ⊢ φ → L ∈ ℝ *
7 smfpimioompt.r ⊢ φ → R ∈ ℝ *
8 eqid ⊢ dom ⁡ x ∈ A ⟼ B = dom ⁡ x ∈ A ⟼ B
9 2 5 8 smff ⊢ φ → x ∈ A ⟼ B : dom ⁡ x ∈ A ⟼ B ⟶ ℝ
10 eqid ⊢ x ∈ A ⟼ B = x ∈ A ⟼ B
11 1 10 4 dmmptdf ⊢ φ → dom ⁡ x ∈ A ⟼ B = A
12 11 feq2d ⊢ φ → x ∈ A ⟼ B : dom ⁡ x ∈ A ⟼ B ⟶ ℝ ↔ x ∈ A ⟼ B : A ⟶ ℝ
13 9 12 mpbid ⊢ φ → x ∈ A ⟼ B : A ⟶ ℝ
14 13 fvmptelcdm ⊢ φ ∧ x ∈ A → B ∈ ℝ
15 14 rexrd ⊢ φ ∧ x ∈ A → B ∈ ℝ *
16 1 6 7 15 pimiooltgt ⊢ φ → x ∈ A | B ∈ L R = x ∈ A | B < R ∩ x ∈ A | L < B
17 eqid ⊢ S ↾ 𝑡 A = S ↾ 𝑡 A
18 2 3 17 subsalsal ⊢ φ → S ↾ 𝑡 A ∈ SAlg
19 1 2 4 5 7 smfpimltxrmpt ⊢ φ → x ∈ A | B < R ∈ S ↾ 𝑡 A
20 1 2 4 5 6 smfpimgtxrmpt ⊢ φ → x ∈ A | L < B ∈ S ↾ 𝑡 A
21 18 19 20 salincld ⊢ φ → x ∈ A | B < R ∩ x ∈ A | L < B ∈ S ↾ 𝑡 A
22 16 21 eqeltrd ⊢ φ → x ∈ A | B ∈ L R ∈ S ↾ 𝑡 A