Theorem nn0red

Description: A nonnegative integer is a real number. (Contributed by Mario Carneiro, 27-May-2016)

	Ref	Expression
Hypothesis	nn0red.1	$$⊢\phi \to A\in {\mathbb{N}}_0$$
Assertion	nn0red	$$⊢\phi \to A\in ℝ$$

Proof

Step	Hyp	Ref	Expression
1		nn0red.1	$$⊢\phi \to A\in {\mathbb{N}}_0$$
2		nn0ssre	$$⊢{\mathbb{N}}_0\subseteq ℝ$$
3	2 1	sseldi	$$⊢\phi \to A\in ℝ$$