Theorem 7m1e6

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

	Ref	Expression
Assertion	7m1e6	|- ( 7 - 1 ) = 6

Proof

Step	Hyp	Ref	Expression
1		6cn	|- 6 e. CC
2		ax-1cn	|- 1 e. CC
3		df-7	|- 7 = ( 6 + 1 )
4	1 2 3	mvrraddi	|- ( 7 - 1 ) = 6