Description: Quantification of two variables over a formula in which they do not occur. (Contributed by Alan Sare, 12-Apr-2011)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | 2ax5 | ⊢ ( 𝜑 → ∀ 𝑥 ∀ 𝑦 𝜑 ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | id | ⊢ ( 𝜑 → 𝜑 ) | |
| 2 | 1 | alrimivv | ⊢ ( 𝜑 → ∀ 𝑥 ∀ 𝑦 𝜑 ) |