Description: The order topology is a topology. (Contributed by Mario Carneiro, 3-Sep-2015)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | ordttop | |- ( R e. V -> ( ordTop ` R ) e. Top ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | eqid | |- dom R = dom R | |
| 2 | 1 | ordttopon | |- ( R e. V -> ( ordTop ` R ) e. ( TopOn ` dom R ) ) | 
| 3 | topontop | |- ( ( ordTop ` R ) e. ( TopOn ` dom R ) -> ( ordTop ` R ) e. Top ) | |
| 4 | 2 3 | syl | |- ( R e. V -> ( ordTop ` R ) e. Top ) |