Linked from
The 8 pages that link to Antichain, each with the reason it gives.
Maximal elementRelated: Every element of a nonempty antichain is maximal within that antichain.
Minimal elementRelated: Every element of a nonempty antichain is minimal within that antichain.
Dilworth's theoremRelated: The theorem’s maximum is taken over all antichains.
Sperner's theoremNarrower topic: Sperner's theorem bounds antichains in the subset order.