Description: A class and its relative complement are disjoint. (Contributed by Thierry Arnoux, 29-Nov-2023)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | disjdifr | ⊢ ( ( 𝐵 ∖ 𝐴 ) ∩ 𝐴 ) = ∅ |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | disjdif | ⊢ ( 𝐴 ∩ ( 𝐵 ∖ 𝐴 ) ) = ∅ | |
| 2 | 1 | ineqcomi | ⊢ ( ( 𝐵 ∖ 𝐴 ) ∩ 𝐴 ) = ∅ |