Metamath Proof Explorer


Theorem elrint2

Description: Membership in a restricted intersection. (Contributed by Stefan O'Rear, 3-Apr-2015)

Ref Expression
Assertion elrint2 ( 𝑋𝐴 → ( 𝑋 ∈ ( 𝐴 𝐵 ) ↔ ∀ 𝑦𝐵 𝑋𝑦 ) )

Proof

Step Hyp Ref Expression
1 elrint ( 𝑋 ∈ ( 𝐴 𝐵 ) ↔ ( 𝑋𝐴 ∧ ∀ 𝑦𝐵 𝑋𝑦 ) )
2 1 baib ( 𝑋𝐴 → ( 𝑋 ∈ ( 𝐴 𝐵 ) ↔ ∀ 𝑦𝐵 𝑋𝑦 ) )