Description: Version of pm11.53v with nonfreeness antecedents. (Contributed by BJ, 7-Oct-2024)
Ref | Expression | ||
---|---|---|---|
Assertion | bj-pm11.53v | ⊢ ( ( ∀ 𝑥 Ⅎ' 𝑦 𝜑 ∧ ∀ 𝑦 Ⅎ' 𝑥 𝜓 ) → ( ∀ 𝑥 ∀ 𝑦 ( 𝜑 → 𝜓 ) ↔ ( ∃ 𝑥 𝜑 → ∀ 𝑦 𝜓 ) ) ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | bj-nnfalt | ⊢ ( ∀ 𝑦 Ⅎ' 𝑥 𝜓 → Ⅎ' 𝑥 ∀ 𝑦 𝜓 ) | |
2 | bj-pm11.53vw | ⊢ ( ( ∀ 𝑥 Ⅎ' 𝑦 𝜑 ∧ Ⅎ' 𝑥 ∀ 𝑦 𝜓 ) → ( ∀ 𝑥 ∀ 𝑦 ( 𝜑 → 𝜓 ) ↔ ( ∃ 𝑥 𝜑 → ∀ 𝑦 𝜓 ) ) ) | |
3 | 1 2 | sylan2 | ⊢ ( ( ∀ 𝑥 Ⅎ' 𝑦 𝜑 ∧ ∀ 𝑦 Ⅎ' 𝑥 𝜓 ) → ( ∀ 𝑥 ∀ 𝑦 ( 𝜑 → 𝜓 ) ↔ ( ∃ 𝑥 𝜑 → ∀ 𝑦 𝜓 ) ) ) |