Metamath Proof Explorer


Theorem nvcli

Description: The norm of a normed complex vector space is a real number. (Contributed by NM, 20-Apr-2007) (New usage is discouraged.)

Ref Expression
Hypotheses nvf.1
|- X = ( BaseSet ` U )
nvf.6
|- N = ( normCV ` U )
nvcli.9
|- U e. NrmCVec
nvcli.7
|- A e. X
Assertion nvcli
|- ( N ` A ) e. RR

Proof

Step Hyp Ref Expression
1 nvf.1
 |-  X = ( BaseSet ` U )
2 nvf.6
 |-  N = ( normCV ` U )
3 nvcli.9
 |-  U e. NrmCVec
4 nvcli.7
 |-  A e. X
5 1 2 nvcl
 |-  ( ( U e. NrmCVec /\ A e. X ) -> ( N ` A ) e. RR )
6 3 4 5 mp2an
 |-  ( N ` A ) e. RR