Description: Restricted quantifier version of Theorem 19.40 of Margaris p. 90. (Contributed by NM, 2-Apr-2004)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | r19.40 | ⊢ ( ∃ 𝑥 ∈ 𝐴 ( 𝜑 ∧ 𝜓 ) → ( ∃ 𝑥 ∈ 𝐴 𝜑 ∧ ∃ 𝑥 ∈ 𝐴 𝜓 ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | simpl | ⊢ ( ( 𝜑 ∧ 𝜓 ) → 𝜑 ) | |
| 2 | 1 | reximi | ⊢ ( ∃ 𝑥 ∈ 𝐴 ( 𝜑 ∧ 𝜓 ) → ∃ 𝑥 ∈ 𝐴 𝜑 ) |
| 3 | simpr | ⊢ ( ( 𝜑 ∧ 𝜓 ) → 𝜓 ) | |
| 4 | 3 | reximi | ⊢ ( ∃ 𝑥 ∈ 𝐴 ( 𝜑 ∧ 𝜓 ) → ∃ 𝑥 ∈ 𝐴 𝜓 ) |
| 5 | 2 4 | jca | ⊢ ( ∃ 𝑥 ∈ 𝐴 ( 𝜑 ∧ 𝜓 ) → ( ∃ 𝑥 ∈ 𝐴 𝜑 ∧ ∃ 𝑥 ∈ 𝐴 𝜓 ) ) |