Description: Theorem 19.34 of Margaris p. 90. (Contributed by NM, 12-Mar-1993)
Ref | Expression | ||
---|---|---|---|
Assertion | 19.34 | ⊢ ( ( ∀ 𝑥 𝜑 ∨ ∃ 𝑥 𝜓 ) → ∃ 𝑥 ( 𝜑 ∨ 𝜓 ) ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | 19.2 | ⊢ ( ∀ 𝑥 𝜑 → ∃ 𝑥 𝜑 ) | |
2 | 1 | orim1i | ⊢ ( ( ∀ 𝑥 𝜑 ∨ ∃ 𝑥 𝜓 ) → ( ∃ 𝑥 𝜑 ∨ ∃ 𝑥 𝜓 ) ) |
3 | 19.43 | ⊢ ( ∃ 𝑥 ( 𝜑 ∨ 𝜓 ) ↔ ( ∃ 𝑥 𝜑 ∨ ∃ 𝑥 𝜓 ) ) | |
4 | 2 3 | sylibr | ⊢ ( ( ∀ 𝑥 𝜑 ∨ ∃ 𝑥 𝜓 ) → ∃ 𝑥 ( 𝜑 ∨ 𝜓 ) ) |