Metamath Proof Explorer


Theorem vitali2

Description: There are non-measurable sets (the Axiom of Choice is used, in the invoked weth ). (Contributed by Glauco Siliprandi, 26-Jun-2021)

Ref Expression
Assertion vitali2 ⊢ dom ⁡ vol ⊂ 𝒫 ℝ

Proof

Step Hyp Ref Expression
1 reex ⊢ ℝ ∈ V
2 weth ⊢ ℝ ∈ V → ∃ o o We ℝ
3 1 2 ax-mp ⊢ ∃ o o We ℝ
4 vitali ⊢ o We ℝ → dom ⁡ vol ⊂ 𝒫 ℝ
5 4 exlimiv ⊢ ∃ o o We ℝ → dom ⁡ vol ⊂ 𝒫 ℝ
6 3 5 ax-mp ⊢ dom ⁡ vol ⊂ 𝒫 ℝ