Description: A nonnegative number plus one is a positive number. (Contributed by Mario Carneiro, 28-May-2016)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | rpgecld.1 | |- ( ph -> A e. RR ) |
|
| ge0p1rp.2 | |- ( ph -> 0 <_ A ) |
||
| Assertion | ge0p1rpd | |- ( ph -> ( A + 1 ) e. RR+ ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | rpgecld.1 | |- ( ph -> A e. RR ) |
|
| 2 | ge0p1rp.2 | |- ( ph -> 0 <_ A ) |
|
| 3 | ge0p1rp | |- ( ( A e. RR /\ 0 <_ A ) -> ( A + 1 ) e. RR+ ) |
|
| 4 | 1 2 3 | syl2anc | |- ( ph -> ( A + 1 ) e. RR+ ) |