Metamath Proof Explorer


Theorem xrge0tmd

Description: The extended nonnegative real numbers monoid is a topological monoid. (Contributed by Thierry Arnoux, 26-Mar-2017) (Proof Shortened by Thierry Arnoux, 21-Jun-2017.)

Ref Expression
Assertion xrge0tmd 𝑠*𝑠0+∞TopMnd

Proof

Step Hyp Ref Expression
1 eqeq1 x=yx=0y=0
2 fveq2 x=ylogx=logy
3 2 negeqd x=ylogx=logy
4 1 3 ifbieq2d x=yifx=0+∞logx=ify=0+∞logy
5 4 cbvmptv x01ifx=0+∞logx=y01ify=0+∞logy
6 xrge0topn TopOpen𝑠*𝑠0+∞=ordTop𝑡0+∞
7 5 6 xrge0iifmhm x01ifx=0+∞logxmulGrpfld𝑠01MndHom𝑠*𝑠0+∞
8 5 6 xrge0iifhmeo x01ifx=0+∞logxIIHomeoTopOpen𝑠*𝑠0+∞
9 cnfldex fldV
10 ovex 01V
11 eqid fld𝑠01=fld𝑠01
12 eqid mulGrpfld=mulGrpfld
13 11 12 mgpress fldV01VmulGrpfld𝑠01=mulGrpfld𝑠01
14 9 10 13 mp2an mulGrpfld𝑠01=mulGrpfld𝑠01
15 11 dfii4 II=TopOpenfld𝑠01
16 14 15 mgptopn II=TopOpenmulGrpfld𝑠01
17 16 oveq1i IIHomeoTopOpen𝑠*𝑠0+∞=TopOpenmulGrpfld𝑠01HomeoTopOpen𝑠*𝑠0+∞
18 8 17 eleqtri x01ifx=0+∞logxTopOpenmulGrpfld𝑠01HomeoTopOpen𝑠*𝑠0+∞
19 eqid mulGrpfld𝑠01=mulGrpfld𝑠01
20 19 iistmd mulGrpfld𝑠01TopMnd
21 xrge0tps 𝑠*𝑠0+∞TopSp
22 7 18 20 21 mhmhmeotmd 𝑠*𝑠0+∞TopMnd