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 𝜑 → 𝜓 ) ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | hba1 | ⊢ ( ∀ 𝑥 𝜑 → ∀ 𝑥 ∀ 𝑥 𝜑 ) | |
2 | hba1 | ⊢ ( ∀ 𝑥 𝜓 → ∀ 𝑥 ∀ 𝑥 𝜓 ) | |
3 | 1 2 | hbim | ⊢ ( ( ∀ 𝑥 𝜑 → ∀ 𝑥 𝜓 ) → ∀ 𝑥 ( ∀ 𝑥 𝜑 → ∀ 𝑥 𝜓 ) ) |
4 | sp | ⊢ ( ∀ 𝑥 𝜓 → 𝜓 ) | |
5 | 4 | imim2i | ⊢ ( ( ∀ 𝑥 𝜑 → ∀ 𝑥 𝜓 ) → ( ∀ 𝑥 𝜑 → 𝜓 ) ) |
6 | 3 5 | alrimih | ⊢ ( ( ∀ 𝑥 𝜑 → ∀ 𝑥 𝜓 ) → ∀ 𝑥 ( ∀ 𝑥 𝜑 → 𝜓 ) ) |