Metamath Proof Explorer


Theorem opelxpi

Description: Ordered pair membership in a Cartesian product (implication). (Contributed by NM, 28-May-1995)

Ref Expression
Assertion opelxpi ⊢ A ∈ C ∧ B ∈ D → A B ∈ C × D

Proof

Step Hyp Ref Expression
1 opelxp ⊢ A B ∈ C × D ↔ A ∈ C ∧ B ∈ D
2 1 biimpri ⊢ A ∈ C ∧ B ∈ D → A B ∈ C × D