Description: Define the set of positive reals. Definition of positive numbers in Apostol p. 20. (Contributed by NM, 27-Oct-2007)
Ref | Expression | ||
---|---|---|---|
Assertion | df-rp | |- RR+ = { x e. RR | 0 < x } |
Step | Hyp | Ref | Expression |
---|---|---|---|
0 | crp | |- RR+ |
|
1 | vx | |- x |
|
2 | cr | |- RR |
|
3 | cc0 | |- 0 |
|
4 | clt | |- < |
|
5 | 1 | cv | |- x |
6 | 3 5 4 | wbr | |- 0 < x |
7 | 6 1 2 | crab | |- { x e. RR | 0 < x } |
8 | 0 7 | wceq | |- RR+ = { x e. RR | 0 < x } |