Metamath Proof Explorer


Theorem bj-inftyexpitaufo

Description: The function inftyexpitau written as a surjection with domain and range. (Contributed by BJ, 4-Feb-2023)

Ref Expression
Assertion bj-inftyexpitaufo ⊢ +∞e iτ : ℝ ⟶ onto ℂ ∞N

Proof

Step Hyp Ref Expression
1 opex ⊢ { R ⁡ 1 st ⁡ x 𝑹 ∈ V
2 df-bj-inftyexpitau ⊢ +∞e iτ = x ∈ ℝ ⟼ { R ⁡ 1 st ⁡ x 𝑹
3 1 2 fnmpti ⊢ +∞e iτ Fn ℝ
4 dffn4 ⊢ +∞e iτ Fn ℝ ↔ +∞e iτ : ℝ ⟶ onto ran ⁡ +∞e iτ
5 3 4 mpbi ⊢ +∞e iτ : ℝ ⟶ onto ran ⁡ +∞e iτ
6 df-bj-ccinftyN ⊢ ℂ ∞N = ran ⁡ +∞e iτ
7 6 eqcomi ⊢ ran ⁡ +∞e iτ = ℂ ∞N
8 foeq3 ⊢ ran ⁡ +∞e iτ = ℂ ∞N → +∞e iτ : ℝ ⟶ onto ran ⁡ +∞e iτ ↔ +∞e iτ : ℝ ⟶ onto ℂ ∞N
9 7 8 ax-mp ⊢ +∞e iτ : ℝ ⟶ onto ran ⁡ +∞e iτ ↔ +∞e iτ : ℝ ⟶ onto ℂ ∞N
10 5 9 mpbi ⊢ +∞e iτ : ℝ ⟶ onto ℂ ∞N