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Description: Deduction form of Theorem 19.9 of Margaris p. 89. (Contributed by NM, 28-Jan-1997)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | exlimdh.1 | ⊢ ( 𝜑 → ∀ 𝑥 𝜑 ) | |
| exlimdh.2 | ⊢ ( 𝜒 → ∀ 𝑥 𝜒 ) | ||
| exlimdh.3 | ⊢ ( 𝜑 → ( 𝜓 → 𝜒 ) ) | ||
| Assertion | exlimdh | ⊢ ( 𝜑 → ( ∃ 𝑥 𝜓 → 𝜒 ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | exlimdh.1 | ⊢ ( 𝜑 → ∀ 𝑥 𝜑 ) | |
| 2 | exlimdh.2 | ⊢ ( 𝜒 → ∀ 𝑥 𝜒 ) | |
| 3 | exlimdh.3 | ⊢ ( 𝜑 → ( 𝜓 → 𝜒 ) ) | |
| 4 | 1 | nf5i | ⊢ Ⅎ 𝑥 𝜑 |
| 5 | 2 | nf5i | ⊢ Ⅎ 𝑥 𝜒 |
| 6 | 4 5 3 | exlimd | ⊢ ( 𝜑 → ( ∃ 𝑥 𝜓 → 𝜒 ) ) |