Description: The generalized sum of nonnegative extended reals is an extended real. (Contributed by Glauco Siliprandi, 11-Oct-2020)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | sge0xrclmpt.xph | ⊢ Ⅎ 𝑥 𝜑 | |
| sge0xrclmpt.a | ⊢ ( 𝜑 → 𝐴 ∈ 𝑉 ) | ||
| sge0xrclmpt.b | ⊢ ( ( 𝜑 ∧ 𝑥 ∈ 𝐴 ) → 𝐵 ∈ ( 0 [,] +∞ ) ) | ||
| Assertion | sge0xrclmpt | ⊢ ( 𝜑 → ( Σ^ ‘ ( 𝑥 ∈ 𝐴 ↦ 𝐵 ) ) ∈ ℝ* ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | sge0xrclmpt.xph | ⊢ Ⅎ 𝑥 𝜑 | |
| 2 | sge0xrclmpt.a | ⊢ ( 𝜑 → 𝐴 ∈ 𝑉 ) | |
| 3 | sge0xrclmpt.b | ⊢ ( ( 𝜑 ∧ 𝑥 ∈ 𝐴 ) → 𝐵 ∈ ( 0 [,] +∞ ) ) | |
| 4 | iccssxr | ⊢ ( 0 [,] +∞ ) ⊆ ℝ* | |
| 5 | 1 2 3 | sge0clmpt | ⊢ ( 𝜑 → ( Σ^ ‘ ( 𝑥 ∈ 𝐴 ↦ 𝐵 ) ) ∈ ( 0 [,] +∞ ) ) |
| 6 | 4 5 | sselid | ⊢ ( 𝜑 → ( Σ^ ‘ ( 𝑥 ∈ 𝐴 ↦ 𝐵 ) ) ∈ ℝ* ) |