Description: Closure of the natural logarithm function. (Contributed by Mario Carneiro, 29-May-2016)
Ref | Expression | ||
---|---|---|---|
Hypothesis | relogcld.1 | |- ( ph -> A e. RR+ ) |
|
Assertion | relogcld | |- ( ph -> ( log ` A ) e. RR ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | relogcld.1 | |- ( ph -> A e. RR+ ) |
|
2 | relogcl | |- ( A e. RR+ -> ( log ` A ) e. RR ) |
|
3 | 1 2 | syl | |- ( ph -> ( log ` A ) e. RR ) |