Description: A number plus its conjugate is twice its real part. Compare Proposition 10-3.4(h) of Gleason p. 133. (Contributed by NM, 2-Oct-1999)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | recl.1 | |- A e. CC |
|
| Assertion | addcji | |- ( A + ( * ` A ) ) = ( 2 x. ( Re ` A ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | recl.1 | |- A e. CC |
|
| 2 | addcj | |- ( A e. CC -> ( A + ( * ` A ) ) = ( 2 x. ( Re ` A ) ) ) |
|
| 3 | 1 2 | ax-mp | |- ( A + ( * ` A ) ) = ( 2 x. ( Re ` A ) ) |