Metamath Proof Explorer


Theorem salincld

Description: The intersection of two sets in a sigma-algebra is in the sigma-algebra. (Contributed by Glauco Siliprandi, 26-Jun-2021)

Ref Expression
Hypotheses salincld.1
|- ( ph -> S e. SAlg )
salincld.2
|- ( ph -> E e. S )
salincld.3
|- ( ph -> F e. S )
Assertion salincld
|- ( ph -> ( E i^i F ) e. S )

Proof

Step Hyp Ref Expression
1 salincld.1
 |-  ( ph -> S e. SAlg )
2 salincld.2
 |-  ( ph -> E e. S )
3 salincld.3
 |-  ( ph -> F e. S )
4 salincl
 |-  ( ( S e. SAlg /\ E e. S /\ F e. S ) -> ( E i^i F ) e. S )
5 1 2 3 4 syl3anc
 |-  ( ph -> ( E i^i F ) e. S )