Metamath Proof Explorer


Theorem elin1d

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 elin1d ⊢ φ → X ∈ A

Proof

Step Hyp Ref Expression
1 elin1d.1 ⊢ φ → X ∈ A ∩ B
2 elinel1 ⊢ X ∈ A ∩ B → X ∈ A
3 1 2 syl ⊢ φ → X ∈ A