Metamath Proof Explorer


Theorem rrvfinvima

Description: For a real-value random variable X , any open interval in RR is the image of a measurable set. (Contributed by Thierry Arnoux, 25-Jan-2017)

Ref Expression
Hypotheses isrrvv.1 ( 𝜑𝑃 ∈ Prob )
rrvvf.1 ( 𝜑𝑋 ∈ ( rRndVar ‘ 𝑃 ) )
Assertion rrvfinvima ( 𝜑 → ∀ 𝑦 ∈ 𝔅 ( 𝑋𝑦 ) ∈ dom 𝑃 )

Proof

Step Hyp Ref Expression
1 isrrvv.1 ( 𝜑𝑃 ∈ Prob )
2 rrvvf.1 ( 𝜑𝑋 ∈ ( rRndVar ‘ 𝑃 ) )
3 1 isrrvv ( 𝜑 → ( 𝑋 ∈ ( rRndVar ‘ 𝑃 ) ↔ ( 𝑋 : dom 𝑃 ⟶ ℝ ∧ ∀ 𝑦 ∈ 𝔅 ( 𝑋𝑦 ) ∈ dom 𝑃 ) ) )
4 2 3 mpbid ( 𝜑 → ( 𝑋 : dom 𝑃 ⟶ ℝ ∧ ∀ 𝑦 ∈ 𝔅 ( 𝑋𝑦 ) ∈ dom 𝑃 ) )
5 4 simprd ( 𝜑 → ∀ 𝑦 ∈ 𝔅 ( 𝑋𝑦 ) ∈ dom 𝑃 )