Description: The imaginary part of a real number is 0. (Contributed by Mario Carneiro, 29-May-2016)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | crred.1 | |- ( ph -> A e. RR ) |
|
| Assertion | reim0d | |- ( ph -> ( Im ` A ) = 0 ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | crred.1 | |- ( ph -> A e. RR ) |
|
| 2 | reim0 | |- ( A e. RR -> ( Im ` A ) = 0 ) |
|
| 3 | 1 2 | syl | |- ( ph -> ( Im ` A ) = 0 ) |