Description: The open sets of a topological ordered space. (Contributed by Mario Carneiro, 12-Nov-2015) (Revised by AV, 9-Sep-2021)
Ref | Expression | ||
---|---|---|---|
Hypothesis | otpsstr.w | ||
Assertion | otpstset |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | otpsstr.w | ||
2 | 1 | otpsstr | |
3 | tsetid | ||
4 | snsstp2 | ||
5 | 4 1 | sseqtrri | |
6 | 2 3 5 | strfv |