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 ∈ ℂ
2		ax-1cn	⊢ 1 ∈ ℂ
3		df-8	⊢ 8 = ( 7 + 1 )
4	1 2 3	mvrraddi	⊢ ( 8 − 1 ) = 7