Metamath Proof Explorer


Theorem hbald

Description: Deduction form of bound-variable hypothesis builder hbal . (Contributed by NM, 2-Jan-2002)

Ref Expression
Hypotheses hbald.1 ⊢ ( 𝜑 → ∀ 𝑦 𝜑 )
hbald.2 ⊢ ( 𝜑 → ( 𝜓 → ∀ 𝑥 𝜓 ) )
Assertion hbald ( 𝜑 → ( ∀ 𝑦 𝜓 → ∀ 𝑥 ∀ 𝑦 𝜓 ) )

Proof

Step Hyp Ref Expression
1 hbald.1 ⊢ ( 𝜑 → ∀ 𝑦 𝜑 )
2 hbald.2 ⊢ ( 𝜑 → ( 𝜓 → ∀ 𝑥 𝜓 ) )
3 1 2 alimdh ⊢ ( 𝜑 → ( ∀ 𝑦 𝜓 → ∀ 𝑦 ∀ 𝑥 𝜓 ) )
4 ax-11 ⊢ ( ∀ 𝑦 ∀ 𝑥 𝜓 → ∀ 𝑥 ∀ 𝑦 𝜓 )
5 3 4 syl6 ⊢ ( 𝜑 → ( ∀ 𝑦 𝜓 → ∀ 𝑥 ∀ 𝑦 𝜓 ) )