![](/files/happy5.png)
Combinatorics
Also see: Graph Theory » Hypergraphs
![Syndicate content Syndicate content](/misc/feed.png)
Imp.¹: Importance (Low ✭, Medium ✭✭, High ✭✭✭, Outstanding ✭✭✭✭)
Rec.²: Recommended for undergraduates.
Note: Resolved problems from this section may be found in Solved problems.