Metamath Proof Explorer


Theorem disjdifr

Description: A class and its relative complement are disjoint. (Contributed by Thierry Arnoux, 29-Nov-2023)

Ref Expression
Assertion disjdifr ( ( 𝐵𝐴 ) ∩ 𝐴 ) = ∅

Proof

Step Hyp Ref Expression
1 disjdif ( 𝐴 ∩ ( 𝐵𝐴 ) ) = ∅
2 1 ineqcomi ( ( 𝐵𝐴 ) ∩ 𝐴 ) = ∅