Metamath Proof Explorer


Theorem mbfpsssmf

Description: Real-valued measurable functions are a proper subset of sigma-measurable functions (w.r.t. the Lebesgue measure on the reals). (Contributed by Glauco Siliprandi, 26-Jun-2021)

Ref Expression
Hypothesis mbfpsssmf.1 ⊢ S = dom ⁡ vol
Assertion mbfpsssmf ⊢ MblFn ∩ ℝ ↑ 𝑝𝑚 ℝ ⊂ SMblFn ⁡ S

Proof

Step Hyp Ref Expression
1 mbfpsssmf.1 ⊢ S = dom ⁡ vol
2 elinel1 ⊢ f ∈ MblFn ∩ ℝ ↑ 𝑝𝑚 ℝ → f ∈ MblFn
3 elinel2 ⊢ f ∈ MblFn ∩ ℝ ↑ 𝑝𝑚 ℝ → f ∈ ℝ ↑ 𝑝𝑚 ℝ
4 elpmrn ⊢ f ∈ ℝ ↑ 𝑝𝑚 ℝ → ran ⁡ f ⊆ ℝ
5 3 4 syl ⊢ f ∈ MblFn ∩ ℝ ↑ 𝑝𝑚 ℝ → ran ⁡ f ⊆ ℝ
6 2 5 1 mbfresmf ⊢ f ∈ MblFn ∩ ℝ ↑ 𝑝𝑚 ℝ → f ∈ SMblFn ⁡ S
7 6 ssriv ⊢ MblFn ∩ ℝ ↑ 𝑝𝑚 ℝ ⊆ SMblFn ⁡ S
8 1 nsssmfmbf ⊢ ¬ SMblFn ⁡ S ⊆ MblFn
9 2 ssriv ⊢ MblFn ∩ ℝ ↑ 𝑝𝑚 ℝ ⊆ MblFn
10 nsstr ⊢ ¬ SMblFn ⁡ S ⊆ MblFn ∧ MblFn ∩ ℝ ↑ 𝑝𝑚 ℝ ⊆ MblFn → ¬ SMblFn ⁡ S ⊆ MblFn ∩ ℝ ↑ 𝑝𝑚 ℝ
11 8 9 10 mp2an ⊢ ¬ SMblFn ⁡ S ⊆ MblFn ∩ ℝ ↑ 𝑝𝑚 ℝ
12 7 11 pm3.2i ⊢ MblFn ∩ ℝ ↑ 𝑝𝑚 ℝ ⊆ SMblFn ⁡ S ∧ ¬ SMblFn ⁡ S ⊆ MblFn ∩ ℝ ↑ 𝑝𝑚 ℝ
13 dfpss3 ⊢ MblFn ∩ ℝ ↑ 𝑝𝑚 ℝ ⊂ SMblFn ⁡ S ↔ MblFn ∩ ℝ ↑ 𝑝𝑚 ℝ ⊆ SMblFn ⁡ S ∧ ¬ SMblFn ⁡ S ⊆ MblFn ∩ ℝ ↑ 𝑝𝑚 ℝ
14 12 13 mpbir ⊢ MblFn ∩ ℝ ↑ 𝑝𝑚 ℝ ⊂ SMblFn ⁡ S