Theorem 0xr

Description: Zero is an extended real. (Contributed by Mario Carneiro, 15-Jun-2014)

	Ref	Expression
Assertion	0xr	$$⊢0\in {ℝ}^{*}$$

Proof

Step	Hyp	Ref	Expression
1		ressxr	$$⊢ℝ\subseteq {ℝ}^{*}$$
2		0re	$$⊢0\in ℝ$$
3	1 2	sselii	$$⊢0\in {ℝ}^{*}$$