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 ) |