Metamath Proof Explorer


Theorem iniin1

Description: Indexed intersection of intersection. (Contributed by Glauco Siliprandi, 23-Oct-2021)

Ref Expression
Assertion iniin1 ( 𝐴 ≠ ∅ → ( ∩ 𝑥 ∈ 𝐴 𝐶 ∩ 𝐵 ) = ∩ 𝑥 ∈ 𝐴 ( 𝐶 ∩ 𝐵 ) )

Proof

Step Hyp Ref Expression
1 iinin1 ⊢ ( 𝐴 ≠ ∅ → ∩ 𝑥 ∈ 𝐴 ( 𝐶 ∩ 𝐵 ) = ( ∩ 𝑥 ∈ 𝐴 𝐶 ∩ 𝐵 ) )
2 1 eqcomd ⊢ ( 𝐴 ≠ ∅ → ( ∩ 𝑥 ∈ 𝐴 𝐶 ∩ 𝐵 ) = ∩ 𝑥 ∈ 𝐴 ( 𝐶 ∩ 𝐵 ) )