Description: Universal quantification implies restricted quantification. (Contributed by NM, 20-Oct-2006)
Ref | Expression | ||
---|---|---|---|
Assertion | alral | ⊢ ( ∀ 𝑥 𝜑 → ∀ 𝑥 ∈ 𝐴 𝜑 ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | ala1 | ⊢ ( ∀ 𝑥 𝜑 → ∀ 𝑥 ( 𝑥 ∈ 𝐴 → 𝜑 ) ) | |
2 | df-ral | ⊢ ( ∀ 𝑥 ∈ 𝐴 𝜑 ↔ ∀ 𝑥 ( 𝑥 ∈ 𝐴 → 𝜑 ) ) | |
3 | 1 2 | sylibr | ⊢ ( ∀ 𝑥 𝜑 → ∀ 𝑥 ∈ 𝐴 𝜑 ) |