Metamath Proof Explorer


Theorem 2alanimi

Description: Removes two universal quantifiers from a statement. (Contributed by Andrew Salmon, 24-May-2011)

Ref Expression
Hypothesis 2alanimi.1 ⊢ φ ∧ ψ → χ
Assertion 2alanimi ⊢ ∀ x ∀ y φ ∧ ∀ x ∀ y ψ → ∀ x ∀ y χ

Proof

Step Hyp Ref Expression
1 2alanimi.1 ⊢ φ ∧ ψ → χ
2 1 alanimi ⊢ ∀ y φ ∧ ∀ y ψ → ∀ y χ
3 2 alanimi ⊢ ∀ x ∀ y φ ∧ ∀ x ∀ y ψ → ∀ x ∀ y χ