Metamath Proof Explorer


Theorem pnfel0pnf

Description: +oo is a nonnegative extended real. (Contributed by Glauco Siliprandi, 17-Aug-2020)

Ref Expression
Assertion pnfel0pnf +∞ ∈ ( 0 [,] +∞ )

Proof

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 [,] +∞ )