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Metamath Proof Explorer

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*