Description: Addition of nonnegative and positive numbers is positive. (Contributed by Mario Carneiro, 27-May-2016)
Ref | Expression | ||
---|---|---|---|
Hypotheses | leidd.1 | |- ( ph -> A e. RR ) |
|
ltnegd.2 | |- ( ph -> B e. RR ) |
||
addgegt0d.3 | |- ( ph -> 0 <_ A ) |
||
addgegt0d.4 | |- ( ph -> 0 < B ) |
||
Assertion | addgegt0d | |- ( ph -> 0 < ( A + B ) ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | leidd.1 | |- ( ph -> A e. RR ) |
|
2 | ltnegd.2 | |- ( ph -> B e. RR ) |
|
3 | addgegt0d.3 | |- ( ph -> 0 <_ A ) |
|
4 | addgegt0d.4 | |- ( ph -> 0 < B ) |
|
5 | addgegt0 | |- ( ( ( A e. RR /\ B e. RR ) /\ ( 0 <_ A /\ 0 < B ) ) -> 0 < ( A + B ) ) |
|
6 | 1 2 3 4 5 | syl22anc | |- ( ph -> 0 < ( A + B ) ) |