Expand on reverse topological power ordering
@@ -257,7 +257,10 @@ First we define:
2. x's origin_server_ts is less than y's, or if
3. x's event_id is lexicographically less than y's
- This is also known as a lexicographical topological sort.
+ This is also known as a lexicographical topological sort (i.e. this is the
+ unique topological ordering such that for an entry x all entries after it
+ must either have x in their auth chain or be greater than x as defined
+ above). This can be implemented using Kahn's algorithm.
* The **"mainline ordering"** based on a power level event P of a set of
events is calculated as follows:
