Description: Membership in an ordered-pair class abstraction. One can remove the DV condition on x , y by using opabid in place of opabidw . (Contributed by BJ, 22-May-2024)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | bj-opelopabid | ⊢ ( 𝑥 { 〈 𝑥 , 𝑦 〉 ∣ 𝜑 } 𝑦 ↔ 𝜑 ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | df-br | ⊢ ( 𝑥 { 〈 𝑥 , 𝑦 〉 ∣ 𝜑 } 𝑦 ↔ 〈 𝑥 , 𝑦 〉 ∈ { 〈 𝑥 , 𝑦 〉 ∣ 𝜑 } ) | |
| 2 | opabidw | ⊢ ( 〈 𝑥 , 𝑦 〉 ∈ { 〈 𝑥 , 𝑦 〉 ∣ 𝜑 } ↔ 𝜑 ) | |
| 3 | 1 2 | bitri | ⊢ ( 𝑥 { 〈 𝑥 , 𝑦 〉 ∣ 𝜑 } 𝑦 ↔ 𝜑 ) |