Description: Binary relation on a Cartesian product. (Contributed by NM, 22-Apr-2004)
Ref | Expression | ||
---|---|---|---|
Assertion | brxp | ⊢ ( 𝐴 ( 𝐶 × 𝐷 ) 𝐵 ↔ ( 𝐴 ∈ 𝐶 ∧ 𝐵 ∈ 𝐷 ) ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | df-br | ⊢ ( 𝐴 ( 𝐶 × 𝐷 ) 𝐵 ↔ 〈 𝐴 , 𝐵 〉 ∈ ( 𝐶 × 𝐷 ) ) | |
2 | opelxp | ⊢ ( 〈 𝐴 , 𝐵 〉 ∈ ( 𝐶 × 𝐷 ) ↔ ( 𝐴 ∈ 𝐶 ∧ 𝐵 ∈ 𝐷 ) ) | |
3 | 1 2 | bitri | ⊢ ( 𝐴 ( 𝐶 × 𝐷 ) 𝐵 ↔ ( 𝐴 ∈ 𝐶 ∧ 𝐵 ∈ 𝐷 ) ) |