Metamath Proof Explorer


Theorem chtcl

Description: Real closure of the Chebyshev function. (Contributed by Mario Carneiro, 15-Sep-2014)

Ref Expression
Assertion chtcl ⊢ A ∈ ℝ → θ ⁡ A ∈ ℝ

Proof

Step Hyp Ref Expression
1 chtf ⊢ θ : ℝ ⟶ ℝ
2 1 ffvelcdmi ⊢ A ∈ ℝ → θ ⁡ A ∈ ℝ