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	$$⊢7\in ℂ$$

Proof

Step	Hyp	Ref	Expression
1		df-7	$$⊢7=6+1$$
2		6cn	$$⊢6\in ℂ$$
3		ax-1cn	$$⊢1\in ℂ$$
4	2 3	addcli	$$⊢6+1\in ℂ$$
5	1 4	eqeltri	$$⊢7\in ℂ$$