Metamath Proof Explorer


Theorem rspec2

Description: Specialization rule for restricted quantification, with two quantifiers. (Contributed by NM, 20-Nov-1994)

Ref Expression
Hypothesis rspec2.1 ⊢ ∀ x ∈ A ∀ y ∈ B φ
Assertion rspec2 ⊢ x ∈ A ∧ y ∈ B → φ

Proof

Step Hyp Ref Expression
1 rspec2.1 ⊢ ∀ x ∈ A ∀ y ∈ B φ
2 1 rspec ⊢ x ∈ A → ∀ y ∈ B φ
3 2 r19.21bi ⊢ x ∈ A ∧ y ∈ B → φ