Metamath Proof Explorer


Theorem pw2f1o2val

Description: Function value of the pw2f1o2 bijection. (Contributed by Stefan O'Rear, 18-Jan-2015) (Revised by Stefan O'Rear, 6-May-2015)

Ref Expression
Hypothesis pw2f1o2.f ⊢ F = x ∈ 2 𝑜 A ⟼ x -1 1 𝑜
Assertion pw2f1o2val ⊢ X ∈ 2 𝑜 A → F ⁡ X = X -1 1 𝑜

Proof

Step Hyp Ref Expression
1 pw2f1o2.f ⊢ F = x ∈ 2 𝑜 A ⟼ x -1 1 𝑜
2 cnvexg ⊢ X ∈ 2 𝑜 A → X -1 ∈ V
3 imaexg ⊢ X -1 ∈ V → X -1 1 𝑜 ∈ V
4 2 3 syl ⊢ X ∈ 2 𝑜 A → X -1 1 𝑜 ∈ V
5 cnveq ⊢ x = X → x -1 = X -1
6 5 imaeq1d ⊢ x = X → x -1 1 𝑜 = X -1 1 𝑜
7 6 1 fvmptg ⊢ X ∈ 2 𝑜 A ∧ X -1 1 𝑜 ∈ V → F ⁡ X = X -1 1 𝑜
8 4 7 mpdan ⊢ X ∈ 2 𝑜 A → F ⁡ X = X -1 1 𝑜