Description: The arbitrary sum of nonnegative extended reals is an extended real. (Contributed by Glauco Siliprandi, 17-Aug-2020)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | sge0xrcl.x | ⊢ ( 𝜑 → 𝑋 ∈ 𝑉 ) | |
| sge0xrcl.f | ⊢ ( 𝜑 → 𝐹 : 𝑋 ⟶ ( 0 [,] +∞ ) ) | ||
| Assertion | sge0xrcl | ⊢ ( 𝜑 → ( Σ^ ‘ 𝐹 ) ∈ ℝ* ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | sge0xrcl.x | ⊢ ( 𝜑 → 𝑋 ∈ 𝑉 ) | |
| 2 | sge0xrcl.f | ⊢ ( 𝜑 → 𝐹 : 𝑋 ⟶ ( 0 [,] +∞ ) ) | |
| 3 | iccssxr | ⊢ ( 0 [,] +∞ ) ⊆ ℝ* | |
| 4 | 1 2 | sge0cl | ⊢ ( 𝜑 → ( Σ^ ‘ 𝐹 ) ∈ ( 0 [,] +∞ ) ) |
| 5 | 3 4 | sselid | ⊢ ( 𝜑 → ( Σ^ ‘ 𝐹 ) ∈ ℝ* ) |