Theorem 7cn

Description: The number 7 is a complex number. (Contributed by David A. Wheeler, 8-Dec-2018) Reduce dependencies on axioms. (Revised by Steven Nguyen, 4-Oct-2022)

	Ref	Expression
Assertion	7cn	|- 7 e. CC

Proof

Step	Hyp	Ref	Expression
1		df-7	|- 7 = ( 6 + 1 )
2		6cn	|- 6 e. CC
3		ax-1cn	|- 1 e. CC
4	2 3	addcli	|- ( 6 + 1 ) e. CC
5	1 4	eqeltri	|- 7 e. CC