Description: The absolute value of a nonzero number is a positive real. (Contributed by Mario Carneiro, 29-May-2016)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | abscld.1 | |- ( ph -> A e. CC ) |
|
| absne0d.2 | |- ( ph -> A =/= 0 ) |
||
| Assertion | absrpcld | |- ( ph -> ( abs ` A ) e. RR+ ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | abscld.1 | |- ( ph -> A e. CC ) |
|
| 2 | absne0d.2 | |- ( ph -> A =/= 0 ) |
|
| 3 | absrpcl | |- ( ( A e. CC /\ A =/= 0 ) -> ( abs ` A ) e. RR+ ) |
|
| 4 | 1 2 3 | syl2anc | |- ( ph -> ( abs ` A ) e. RR+ ) |