This is an inofficial mirror of http://metamath.tirix.org for personal testing of a visualizer extension only.
Description: Restricted existential specialization, using implicit substitution. (Contributed by NM, 26-May-1998) Drop ax-10 , ax-11 , ax-12 . (Revised by SN, 12-Dec-2023)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | rspcv.1 | ⊢ ( 𝑥 = 𝐴 → ( 𝜑 ↔ 𝜓 ) ) | |
| Assertion | rspcev | ⊢ ( ( 𝐴 ∈ 𝐵 ∧ 𝜓 ) → ∃ 𝑥 ∈ 𝐵 𝜑 ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | rspcv.1 | ⊢ ( 𝑥 = 𝐴 → ( 𝜑 ↔ 𝜓 ) ) | |
| 2 | id | ⊢ ( 𝐴 ∈ 𝐵 → 𝐴 ∈ 𝐵 ) | |
| 3 | 1 | adantl | ⊢ ( ( 𝐴 ∈ 𝐵 ∧ 𝑥 = 𝐴 ) → ( 𝜑 ↔ 𝜓 ) ) |
| 4 | 2 3 | rspcedv | ⊢ ( 𝐴 ∈ 𝐵 → ( 𝜓 → ∃ 𝑥 ∈ 𝐵 𝜑 ) ) |
| 5 | 4 | imp | ⊢ ( ( 𝐴 ∈ 𝐵 ∧ 𝜓 ) → ∃ 𝑥 ∈ 𝐵 𝜑 ) |