Description: Closure of the natural logarithm function. (Contributed by NM, 21-Apr-2008) (Revised by Mario Carneiro, 23-Sep-2014)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | logcl | |- ( ( A e. CC /\ A =/= 0 ) -> ( log ` A ) e. CC ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | logrncl | |- ( ( A e. CC /\ A =/= 0 ) -> ( log ` A ) e. ran log ) |
|
| 2 | logrncn | |- ( ( log ` A ) e. ran log -> ( log ` A ) e. CC ) |
|
| 3 | 1 2 | syl | |- ( ( A e. CC /\ A =/= 0 ) -> ( log ` A ) e. CC ) |