Metamath Proof Explorer


Theorem orvcelval

Description: Preimage maps produced by the membership relation. (Contributed by Thierry Arnoux, 6-Feb-2017)

Ref Expression
Hypotheses dstrvprob.1 ⊢ φ → P ∈ Prob
dstrvprob.2 ⊢ φ → X ∈ RndVar ℝ ⁡ P
orvcelel.1 ⊢ φ → A ∈ 𝔅 ℝ
Assertion orvcelval ⊢ φ → X E RV/c A = X -1 A

Proof

Step Hyp Ref Expression
1 dstrvprob.1 ⊢ φ → P ∈ Prob
2 dstrvprob.2 ⊢ φ → X ∈ RndVar ℝ ⁡ P
3 orvcelel.1 ⊢ φ → A ∈ 𝔅 ℝ
4 1 2 3 orrvcval4 ⊢ φ → X E RV/c A = X -1 x ∈ ℝ | x E A
5 epelg ⊢ A ∈ 𝔅 ℝ → x E A ↔ x ∈ A
6 3 5 syl ⊢ φ → x E A ↔ x ∈ A
7 6 rabbidv ⊢ φ → x ∈ ℝ | x E A = x ∈ ℝ | x ∈ A
8 dfin5 ⊢ ℝ ∩ A = x ∈ ℝ | x ∈ A
9 8 a1i ⊢ φ → ℝ ∩ A = x ∈ ℝ | x ∈ A
10 elssuni ⊢ A ∈ 𝔅 ℝ → A ⊆ ⋃ 𝔅 ℝ
11 unibrsiga ⊢ ⋃ 𝔅 ℝ = ℝ
12 10 11 sseqtrdi ⊢ A ∈ 𝔅 ℝ → A ⊆ ℝ
13 3 12 syl ⊢ φ → A ⊆ ℝ
14 sseqin2 ⊢ A ⊆ ℝ ↔ ℝ ∩ A = A
15 13 14 sylib ⊢ φ → ℝ ∩ A = A
16 7 9 15 3eqtr2d ⊢ φ → x ∈ ℝ | x E A = A
17 16 imaeq2d ⊢ φ → X -1 x ∈ ℝ | x E A = X -1 A
18 4 17 eqtrd ⊢ φ → X E RV/c A = X -1 A