Metamath Proof Explorer


Theorem inn0

Description: A nonempty intersection. (Contributed by Glauco Siliprandi, 24-Dec-2020)

Ref Expression
Assertion inn0 ( ( 𝐴 ∩ 𝐵 ) ≠ ∅ ↔ ∃ 𝑥 ∈ 𝐴 𝑥 ∈ 𝐵 )

Proof

Step Hyp Ref Expression
1 nfcv ⊢ Ⅎ 𝑥 𝐴
2 nfcv ⊢ Ⅎ 𝑥 𝐵
3 1 2 inn0f ⊢ ( ( 𝐴 ∩ 𝐵 ) ≠ ∅ ↔ ∃ 𝑥 ∈ 𝐴 𝑥 ∈ 𝐵 )