Metamath Proof Explorer


Theorem oprab4

Description: Two ways to state the domain of an operation. (Contributed by FL, 24-Jan-2010)

Ref Expression
Assertion oprab4 ⊢ x y z | x y ∈ A × B ∧ φ = x y z | x ∈ A ∧ y ∈ B ∧ φ

Proof

Step Hyp Ref Expression
1 opelxp ⊢ x y ∈ A × B ↔ x ∈ A ∧ y ∈ B
2 1 anbi1i ⊢ x y ∈ A × B ∧ φ ↔ x ∈ A ∧ y ∈ B ∧ φ
3 2 oprabbii ⊢ x y z | x y ∈ A × B ∧ φ = x y z | x ∈ A ∧ y ∈ B ∧ φ