Prove the following by deductive system(Using First-order Logic): If x does not occur in ψ, then ∃x : S • (φ(x) ⇒ ψ) ⊨ (∀x : S • φ(x)) ⇒ ψ.
时间: 2024-05-30 20:13:01 浏览: 105
Leader-following consensus of second-order agents with multiple time-varying delays
1. Assume that x does not occur in ψ.
2. Let a be an arbitrary element of S such that φ(a) ⇒ ψ.
3. Assume ∀x : S • φ(x).
4. By Universal Instantiation, φ(a).
5. Using Modus Ponens with (2) and (4), we can conclude that ψ.
6. Therefore, (∀x : S • φ(x)) ⇒ ψ, as desired.
阅读全文