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Metamath Proof Explorer
Description: A difference of two classes is contained in the minuend. Deduction form
of difss . (Contributed by David Moews, 1-May-2017)
|
|
Ref |
Expression |
|
Assertion |
difssd |
⊢ ( 𝜑 → ( 𝐴 ∖ 𝐵 ) ⊆ 𝐴 ) |
Proof
| Step |
Hyp |
Ref |
Expression |
| 1 |
|
difss |
⊢ ( 𝐴 ∖ 𝐵 ) ⊆ 𝐴 |
| 2 |
1
|
a1i |
⊢ ( 𝜑 → ( 𝐴 ∖ 𝐵 ) ⊆ 𝐴 ) |