Theorem 0xr

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

	Ref	Expression
Assertion	0xr	⊢ 0 ∈ ℝ*

Proof

Step	Hyp	Ref	Expression
1		ressxr	⊢ ℝ ⊆ ℝ*
2		0re	⊢ 0 ∈ ℝ
3	1 2	sselii	⊢ 0 ∈ ℝ*