Theorem difssd

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 )