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 = ( normCV𝑈 )
Assertion nvcl ( ( 𝑈 ∈ NrmCVec ∧ 𝐴𝑋 ) → ( 𝑁𝐴 ) ∈ ℝ )

Proof

Step Hyp Ref Expression
1 nvf.1 𝑋 = ( BaseSet ‘ 𝑈 )
2 nvf.6 𝑁 = ( normCV𝑈 )
3 1 2 nvf ( 𝑈 ∈ NrmCVec → 𝑁 : 𝑋 ⟶ ℝ )
4 3 ffvelrnda ( ( 𝑈 ∈ NrmCVec ∧ 𝐴𝑋 ) → ( 𝑁𝐴 ) ∈ ℝ )