Description: Two ways to express a binary relation which is the intersection of a class. (Contributed by RP, 4-Apr-2020)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | brintclab | ⊢ ( 𝐴 ∩ { 𝑥 ∣ 𝜑 } 𝐵 ↔ ∀ 𝑥 ( 𝜑 → 〈 𝐴 , 𝐵 〉 ∈ 𝑥 ) ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | df-br | ⊢ ( 𝐴 ∩ { 𝑥 ∣ 𝜑 } 𝐵 ↔ 〈 𝐴 , 𝐵 〉 ∈ ∩ { 𝑥 ∣ 𝜑 } ) | |
| 2 | opex | ⊢ 〈 𝐴 , 𝐵 〉 ∈ V | |
| 3 | 2 | elintab | ⊢ ( 〈 𝐴 , 𝐵 〉 ∈ ∩ { 𝑥 ∣ 𝜑 } ↔ ∀ 𝑥 ( 𝜑 → 〈 𝐴 , 𝐵 〉 ∈ 𝑥 ) ) | 
| 4 | 1 3 | bitri | ⊢ ( 𝐴 ∩ { 𝑥 ∣ 𝜑 } 𝐵 ↔ ∀ 𝑥 ( 𝜑 → 〈 𝐴 , 𝐵 〉 ∈ 𝑥 ) ) |