Metamath Proof Explorer


Theorem elin2d

Description: Elementhood in the first set of an intersection - deduction version. (Contributed by Thierry Arnoux, 3-May-2020)

Ref Expression
Hypothesis elin1d.1 ⊢ φ → X ∈ A ∩ B
Assertion elin2d ⊢ φ → X ∈ B

Proof

Step Hyp Ref Expression
1 elin1d.1 ⊢ φ → X ∈ A ∩ B
2 elinel2 ⊢ X ∈ A ∩ B → X ∈ B
3 1 2 syl ⊢ φ → X ∈ B