Duality (order theory): Mathematics, Order Theory, Partially Ordered Set

Schnyder's Theorem: Mathematics, Graph Theory, Planar Graph, Order Dimension, Partially Ordered Set

Semilattice: Partially Ordered Set, Least Upper Bound, Nonempty Duality (Order Theory), Greatest Lower Bound

Tree (Set Theory): set Theory, Partially Ordered Set, Suslin Tree, Well Ordered,...

Antichain: Mathematics, Order theory, Partially ordered set, Strong antichain, subset, Total order,...