Theorem 1cnd

Description: One is a complex number, deduction form. (Contributed by David A. Wheeler, 6-Dec-2018)

	Ref	Expression
Assertion	1cnd	$$⊢\phi \to 1\in ℂ$$

Proof

Step	Hyp	Ref	Expression
1		ax-1cn	$$⊢1\in ℂ$$
2	1	a1i	$$⊢\phi \to 1\in ℂ$$