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Description: Inference from Theorem 19.21 of Margaris p. 90. (Restricted quantifier version.) (Contributed by NM, 20-Nov-1994) (Proof shortened by Wolf Lammen, 11-Jun-2023)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | r19.21bi.1 | ⊢ ( 𝜑 → ∀ 𝑥 ∈ 𝐴 𝜓 ) | |
| Assertion | r19.21bi | ⊢ ( ( 𝜑 ∧ 𝑥 ∈ 𝐴 ) → 𝜓 ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | r19.21bi.1 | ⊢ ( 𝜑 → ∀ 𝑥 ∈ 𝐴 𝜓 ) | |
| 2 | rspa | ⊢ ( ( ∀ 𝑥 ∈ 𝐴 𝜓 ∧ 𝑥 ∈ 𝐴 ) → 𝜓 ) | |
| 3 | 1 2 | sylan | ⊢ ( ( 𝜑 ∧ 𝑥 ∈ 𝐴 ) → 𝜓 ) |