This is an inofficial mirror of http://metamath.tirix.org for personal testing of a visualizer extension only.

Metamath Proof Explorer

Theorem nnex

Description: The set of positive integers exists. (Contributed by NM, 3-Oct-1999) (Revised by Mario Carneiro, 17-Nov-2014)

		Ref	Expression
	Assertion	nnex	⊢ ℕ ∈ V

Step	Hyp	Ref	Expression
1		cnex	⊢ ℂ ∈ V
2		nnsscn	⊢ ℕ ⊆ ℂ
3	1 2	ssexi	⊢ ℕ ∈ V