Metamath Proof Explorer


Theorem rspec3

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

Ref Expression
Hypothesis rspec3.1 ⊢ ∀ x ∈ A ∀ y ∈ B ∀ z ∈ C φ
Assertion rspec3 ⊢ x ∈ A ∧ y ∈ B ∧ z ∈ C → φ

Proof

Step Hyp Ref Expression
1 rspec3.1 ⊢ ∀ x ∈ A ∀ y ∈ B ∀ z ∈ C φ
2 1 rspec2 ⊢ x ∈ A ∧ y ∈ B → ∀ z ∈ C φ
3 2 r19.21bi ⊢ x ∈ A ∧ y ∈ B ∧ z ∈ C → φ
4 3 3impa ⊢ x ∈ A ∧ y ∈ B ∧ z ∈ C → φ