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Metamath Proof Explorer

Theorem letop

Description: The topology of the extended reals. (Contributed by Mario Carneiro, 3-Sep-2015)

		Ref	Expression
	Assertion	letop	⊢ ( ordTop ‘ ≤ ) ∈ Top

Step	Hyp	Ref	Expression
1		letopon	⊢ ( ordTop ‘ ≤ ) ∈ ( TopOn ‘ ℝ^* )
2	1	topontopi	⊢ ( ordTop ‘ ≤ ) ∈ Top