This is an inofficial mirror of http://metamath.tirix.org for personal testing of a visualizer extension only.
Metamath Proof Explorer
Description: De Morgan's law for union. Theorem 5.2(13) of Stoll p. 19.
(Contributed by NM, 18-Aug-2004)
|
|
Ref |
Expression |
|
Assertion |
undm |
⊢ ( V ∖ ( 𝐴 ∪ 𝐵 ) ) = ( ( V ∖ 𝐴 ) ∩ ( V ∖ 𝐵 ) ) |
Proof
| Step |
Hyp |
Ref |
Expression |
| 1 |
|
difundi |
⊢ ( V ∖ ( 𝐴 ∪ 𝐵 ) ) = ( ( V ∖ 𝐴 ) ∩ ( V ∖ 𝐵 ) ) |