Theorem nnxrd

Description: A natural number is an extended real. (Contributed by Glauco Siliprandi, 11-Dec-2019)

	Ref	Expression
Hypothesis	nnxrd.1	$$⊢\phi \to A\in \mathbb{N}$$
Assertion	nnxrd	$$⊢\phi \to A\in {ℝ}^{*}$$

Proof

Step	Hyp	Ref	Expression
1		nnxrd.1	$$⊢\phi \to A\in \mathbb{N}$$
2	1	nnred	$$⊢\phi \to A\in ℝ$$
3	2	rexrd	$$⊢\phi \to A\in {ℝ}^{*}$$