Metamath Proof Explorer


Theorem iinexd

Description: The existence of an indexed union. x is normally a free-variable parameter in B , which should be read B ( x ) . (Contributed by Glauco Siliprandi, 23-Oct-2021)

Ref Expression
Hypotheses iinexd.1 ⊢ ( 𝜑 → 𝐴 ≠ ∅ )
iinexd.2 ⊢ ( 𝜑 → ∀ 𝑥 ∈ 𝐴 𝐵 ∈ 𝐶 )
Assertion iinexd ( 𝜑 → ∩ 𝑥 ∈ 𝐴 𝐵 ∈ V )

Proof

Step Hyp Ref Expression
1 iinexd.1 ⊢ ( 𝜑 → 𝐴 ≠ ∅ )
2 iinexd.2 ⊢ ( 𝜑 → ∀ 𝑥 ∈ 𝐴 𝐵 ∈ 𝐶 )
3 iinexg ⊢ ( ( 𝐴 ≠ ∅ ∧ ∀ 𝑥 ∈ 𝐴 𝐵 ∈ 𝐶 ) → ∩ 𝑥 ∈ 𝐴 𝐵 ∈ V )
4 1 2 3 syl2anc ⊢ ( 𝜑 → ∩ 𝑥 ∈ 𝐴 𝐵 ∈ V )