Description: A complex number times its conjugate is nonnegative. (Contributed by NM, 28-May-1999)
Ref | Expression | ||
---|---|---|---|
Hypothesis | recl.1 | |- A e. CC |
|
Assertion | cjmulge0i | |- 0 <_ ( A x. ( * ` A ) ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | recl.1 | |- A e. CC |
|
2 | cjmulge0 | |- ( A e. CC -> 0 <_ ( A x. ( * ` A ) ) ) |
|
3 | 1 2 | ax-mp | |- 0 <_ ( A x. ( * ` A ) ) |