Metamath Proof Explorer


Theorem xrge0tps

Description: The extended nonnegative real numbers monoid forms a topological space. (Contributed by Thierry Arnoux, 19-Jun-2017)

Ref Expression
Assertion xrge0tps 𝑠*𝑠0+∞TopSp

Proof

Step Hyp Ref Expression
1 xrstps 𝑠*TopSp
2 ovex 0+∞V
3 resstps 𝑠*TopSp0+∞V𝑠*𝑠0+∞TopSp
4 1 2 3 mp2an 𝑠*𝑠0+∞TopSp