Description: Deduction form of bound-variable hypothesis builder hbal . (Contributed by NM, 2-Jan-2002)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | hbald.1 | ⊢ ( 𝜑 → ∀ 𝑦 𝜑 ) | |
| hbald.2 | ⊢ ( 𝜑 → ( 𝜓 → ∀ 𝑥 𝜓 ) ) | ||
| Assertion | hbald | ⊢ ( 𝜑 → ( ∀ 𝑦 𝜓 → ∀ 𝑥 ∀ 𝑦 𝜓 ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | hbald.1 | ⊢ ( 𝜑 → ∀ 𝑦 𝜑 ) | |
| 2 | hbald.2 | ⊢ ( 𝜑 → ( 𝜓 → ∀ 𝑥 𝜓 ) ) | |
| 3 | 1 2 | alimdh | ⊢ ( 𝜑 → ( ∀ 𝑦 𝜓 → ∀ 𝑦 ∀ 𝑥 𝜓 ) ) |
| 4 | ax-11 | ⊢ ( ∀ 𝑦 ∀ 𝑥 𝜓 → ∀ 𝑥 ∀ 𝑦 𝜓 ) | |
| 5 | 3 4 | syl6 | ⊢ ( 𝜑 → ( ∀ 𝑦 𝜓 → ∀ 𝑥 ∀ 𝑦 𝜓 ) ) |