Metamath Proof Explorer


Theorem bnj1351

Description: First-order logic and set theory. (Contributed by Jonathan Ben-Naim, 3-Jun-2011) (New usage is discouraged.)

Ref Expression
Hypothesis bnj1351.1 ⊢ φ → ∀ x φ
Assertion bnj1351 ⊢ φ ∧ ψ → ∀ x φ ∧ ψ

Proof

Step Hyp Ref Expression
1 bnj1351.1 ⊢ φ → ∀ x φ
2 ax-5 ⊢ ψ → ∀ x ψ
3 1 2 hban ⊢ φ ∧ ψ → ∀ x φ ∧ ψ