Metamath Proof Explorer


Theorem axi5r

Description: Converse of axc4 (intuitionistic logic axiom ax-i5r). (Contributed by Jim Kingdon, 31-Dec-2017)

Ref Expression
Assertion axi5r ( ( ∀ 𝑥 𝜑 → ∀ 𝑥 𝜓 ) → ∀ 𝑥 ( ∀ 𝑥 𝜑𝜓 ) )

Proof

Step Hyp Ref Expression
1 hba1 ( ∀ 𝑥 𝜑 → ∀ 𝑥𝑥 𝜑 )
2 hba1 ( ∀ 𝑥 𝜓 → ∀ 𝑥𝑥 𝜓 )
3 1 2 hbim ( ( ∀ 𝑥 𝜑 → ∀ 𝑥 𝜓 ) → ∀ 𝑥 ( ∀ 𝑥 𝜑 → ∀ 𝑥 𝜓 ) )
4 sp ( ∀ 𝑥 𝜓𝜓 )
5 4 imim2i ( ( ∀ 𝑥 𝜑 → ∀ 𝑥 𝜓 ) → ( ∀ 𝑥 𝜑𝜓 ) )
6 3 5 alrimih ( ( ∀ 𝑥 𝜑 → ∀ 𝑥 𝜓 ) → ∀ 𝑥 ( ∀ 𝑥 𝜑𝜓 ) )