Description: The extended nonnegative real numbers monoid forms a topological space. (Contributed by Thierry Arnoux, 19-Jun-2017)
Ref | Expression | ||
---|---|---|---|
Assertion | xrge0tps | ⊢ ( ℝ*𝑠 ↾s ( 0 [,] +∞ ) ) ∈ TopSp |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | xrstps | ⊢ ℝ*𝑠 ∈ TopSp | |
2 | ovex | ⊢ ( 0 [,] +∞ ) ∈ V | |
3 | resstps | ⊢ ( ( ℝ*𝑠 ∈ TopSp ∧ ( 0 [,] +∞ ) ∈ V ) → ( ℝ*𝑠 ↾s ( 0 [,] +∞ ) ) ∈ TopSp ) | |
4 | 1 2 3 | mp2an | ⊢ ( ℝ*𝑠 ↾s ( 0 [,] +∞ ) ) ∈ TopSp |