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Metamath Proof Explorer

Theorem difeq2i

Description: Inference adding difference to the left in a class equality. (Contributed by NM, 15-Nov-2002)

		Ref	Expression
	Hypothesis	difeq1i.1	$⊢ A = B$
	Assertion	difeq2i	$⊢ C ∖ A = C ∖ B$

Step	Hyp	Ref	Expression
1		difeq1i.1	$⊢ A = B$
2		difeq2	$⊢ A = B \to C ∖ A = C ∖ B$
3	1 2	ax-mp	$⊢ C ∖ A = C ∖ B$