Description: An extension of RR is a topological space. (Contributed by Thierry Arnoux, 7-Sep-2018)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | rrexttps | |- ( R e. RRExt -> R e. TopSp ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | rrextnrg | |- ( R e. RRExt -> R e. NrmRing ) | |
| 2 | nrgngp | |- ( R e. NrmRing -> R e. NrmGrp ) | |
| 3 | ngpxms | |- ( R e. NrmGrp -> R e. *MetSp ) | |
| 4 | xmstps | |- ( R e. *MetSp -> R e. TopSp ) | |
| 5 | 1 2 3 4 | 4syl | |- ( R e. RRExt -> R e. TopSp ) |