Theorem 8m1e7

Description: 8 - 1 = 7. (Contributed by AV, 6-Sep-2021)

	Ref	Expression
Assertion	8m1e7	|- ( 8 - 1 ) = 7

Proof

Step	Hyp	Ref	Expression
1		7cn	|- 7 e. CC
2		ax-1cn	|- 1 e. CC
3		df-8	|- 8 = ( 7 + 1 )
4	1 2 3	mvrraddi	|- ( 8 - 1 ) = 7