Theorem 2oexOLD

Description: Obsolete version of 2oex as of 19-Sep-2024. (Contributed by BJ, 6-Apr-2019) (Proof modification is discouraged.) (New usage is discouraged.)

	Ref	Expression
Assertion	2oexOLD	⊢ 2o ∈ V

Proof

Step	Hyp	Ref	Expression
1		df-2o	⊢ 2o = suc 1o
2		1oex	⊢ 1o ∈ V
3	2	sucex	⊢ suc 1o ∈ V
4	1 3	eqeltri	⊢ 2o ∈ V