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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

Proof

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