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 | 
| 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 |