Description: A set is an element of any sigma-algebra on it. (Contributed by Glauco Siliprandi, 26-Jun-2021)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | salunid.1 | ⊢ ( 𝜑 → 𝑆 ∈ SAlg ) | |
| Assertion | salunid | ⊢ ( 𝜑 → ∪ 𝑆 ∈ 𝑆 ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | salunid.1 | ⊢ ( 𝜑 → 𝑆 ∈ SAlg ) | |
| 2 | saluni | ⊢ ( 𝑆 ∈ SAlg → ∪ 𝑆 ∈ 𝑆 ) | |
| 3 | 1 2 | syl | ⊢ ( 𝜑 → ∪ 𝑆 ∈ 𝑆 ) |