Metamath Proof Explorer


Theorem salgencld

Description: SalGen actually generates a sigma-algebra. (Contributed by Glauco Siliprandi, 26-Jun-2021)

Ref Expression
Hypotheses salgencld.1 ⊢ φ → X ∈ V
salgencld.2 ⊢ S = SalGen ⁡ X
Assertion salgencld ⊢ φ → S ∈ SAlg

Proof

Step Hyp Ref Expression
1 salgencld.1 ⊢ φ → X ∈ V
2 salgencld.2 ⊢ S = SalGen ⁡ X
3 salgencl ⊢ X ∈ V → SalGen ⁡ X ∈ SAlg
4 1 3 syl ⊢ φ → SalGen ⁡ X ∈ SAlg
5 2 4 eqeltrid ⊢ φ → S ∈ SAlg