Metamath Proof Explorer


Theorem nvcl

Description: The norm of a normed complex vector space is a real number. (Contributed by NM, 24-Nov-2006) (New usage is discouraged.)

Ref Expression
Hypotheses nvf.1 ⊢ X = BaseSet ⁡ U
nvf.6 ⊢ N = norm CV ⁡ U
Assertion nvcl ⊢ U ∈ NrmCVec ∧ A ∈ X → N ⁡ A ∈ ℝ

Proof

Step Hyp Ref Expression
1 nvf.1 ⊢ X = BaseSet ⁡ U
2 nvf.6 ⊢ N = norm CV ⁡ U
3 1 2 nvf ⊢ U ∈ NrmCVec → N : X ⟶ ℝ
4 3 ffvelcdmda ⊢ U ∈ NrmCVec ∧ A ∈ X → N ⁡ A ∈ ℝ