Description: +oo is a nonnegative extended real. (Contributed by Glauco Siliprandi, 17-Aug-2020)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | pnfel0pnf | ⊢ +∞ ∈ ( 0 [,] +∞ ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | 0xr | ⊢ 0 ∈ ℝ* | |
| 2 | pnfxr | ⊢ +∞ ∈ ℝ* | |
| 3 | 0lepnf | ⊢ 0 ≤ +∞ | |
| 4 | ubicc2 | ⊢ ( ( 0 ∈ ℝ* ∧ +∞ ∈ ℝ* ∧ 0 ≤ +∞ ) → +∞ ∈ ( 0 [,] +∞ ) ) | |
| 5 | 1 2 3 4 | mp3an | ⊢ +∞ ∈ ( 0 [,] +∞ ) |