Metamath Proof Explorer


Theorem vdif0

Description: Universal class equality in terms of empty difference. (Contributed by NM, 17-Sep-2003)

Ref Expression
Assertion vdif0 ( 𝐴 = V ↔ ( V ∖ 𝐴 ) = ∅ )

Proof

Step Hyp Ref Expression
1 vss ( V ⊆ 𝐴𝐴 = V )
2 ssdif0 ( V ⊆ 𝐴 ↔ ( V ∖ 𝐴 ) = ∅ )
3 1 2 bitr3i ( 𝐴 = V ↔ ( V ∖ 𝐴 ) = ∅ )