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Metamath Proof Explorer

Theorem 4z

Description: 4 is an integer. (Contributed by BJ, 26-Mar-2020)

		Ref	Expression
	Assertion	4z	$⊢ 4 \in ℤ$

Step	Hyp	Ref	Expression
1		4nn	$⊢ 4 \in ℕ$
2	1	nnzi	$⊢ 4 \in ℤ$