Description: Closure law for division of positive reals. (Contributed by Mario Carneiro, 28-May-2016)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | rpred.1 | |- ( ph -> A e. RR+ ) |
|
| rpaddcld.1 | |- ( ph -> B e. RR+ ) |
||
| Assertion | rpdivcld | |- ( ph -> ( A / B ) e. RR+ ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | rpred.1 | |- ( ph -> A e. RR+ ) |
|
| 2 | rpaddcld.1 | |- ( ph -> B e. RR+ ) |
|
| 3 | rpdivcl | |- ( ( A e. RR+ /\ B e. RR+ ) -> ( A / B ) e. RR+ ) |
|
| 4 | 1 2 3 | syl2anc | |- ( ph -> ( A / B ) e. RR+ ) |