Description: The number 3 is positive. (Contributed by NM, 27-May-1999)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | 3pos | ⊢ 0 < 3 |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | 2re | ⊢ 2 ∈ ℝ | |
| 2 | 1re | ⊢ 1 ∈ ℝ | |
| 3 | 2pos | ⊢ 0 < 2 | |
| 4 | 0lt1 | ⊢ 0 < 1 | |
| 5 | 1 2 3 4 | addgt0ii | ⊢ 0 < ( 2 + 1 ) |
| 6 | df-3 | ⊢ 3 = ( 2 + 1 ) | |
| 7 | 5 6 | breqtrri | ⊢ 0 < 3 |