Description: Sufficient condition for the intersection of a range Cartesian product with a Cartesian product to be a set. (Contributed by Peter Mazsa, 12-Apr-2020)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | xrninxpex | ⊢ ( ( 𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊 ∧ 𝐶 ∈ 𝑋 ) → ( ( 𝑅 ⋉ 𝑆 ) ∩ ( 𝐴 × ( 𝐵 × 𝐶 ) ) ) ∈ V ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | xpexg | ⊢ ( ( 𝐵 ∈ 𝑊 ∧ 𝐶 ∈ 𝑋 ) → ( 𝐵 × 𝐶 ) ∈ V ) | |
| 2 | inxpex | ⊢ ( ( ( 𝑅 ⋉ 𝑆 ) ∈ V ∨ ( 𝐴 ∈ 𝑉 ∧ ( 𝐵 × 𝐶 ) ∈ V ) ) → ( ( 𝑅 ⋉ 𝑆 ) ∩ ( 𝐴 × ( 𝐵 × 𝐶 ) ) ) ∈ V ) | |
| 3 | 2 | olcs | ⊢ ( ( 𝐴 ∈ 𝑉 ∧ ( 𝐵 × 𝐶 ) ∈ V ) → ( ( 𝑅 ⋉ 𝑆 ) ∩ ( 𝐴 × ( 𝐵 × 𝐶 ) ) ) ∈ V ) |
| 4 | 1 3 | sylan2 | ⊢ ( ( 𝐴 ∈ 𝑉 ∧ ( 𝐵 ∈ 𝑊 ∧ 𝐶 ∈ 𝑋 ) ) → ( ( 𝑅 ⋉ 𝑆 ) ∩ ( 𝐴 × ( 𝐵 × 𝐶 ) ) ) ∈ V ) |
| 5 | 4 | 3impb | ⊢ ( ( 𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊 ∧ 𝐶 ∈ 𝑋 ) → ( ( 𝑅 ⋉ 𝑆 ) ∩ ( 𝐴 × ( 𝐵 × 𝐶 ) ) ) ∈ V ) |