Description: Closed form of nexdv . (Contributed by BJ, 20-Oct-2019)
Ref | Expression | ||
---|---|---|---|
Assertion | bj-nexdvt | ⊢ ( ∀ 𝑥 ( 𝜑 → ¬ 𝜓 ) → ( 𝜑 → ¬ ∃ 𝑥 𝜓 ) ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | nfv | ⊢ Ⅎ 𝑥 𝜑 | |
2 | bj-nexdt | ⊢ ( Ⅎ 𝑥 𝜑 → ( ∀ 𝑥 ( 𝜑 → ¬ 𝜓 ) → ( 𝜑 → ¬ ∃ 𝑥 𝜓 ) ) ) | |
3 | 1 2 | ax-mp | ⊢ ( ∀ 𝑥 ( 𝜑 → ¬ 𝜓 ) → ( 𝜑 → ¬ ∃ 𝑥 𝜓 ) ) |