The dimension of planar posets
نویسندگان
چکیده
A partially ordered set (poset) is planar if it has a planar Hasse diagram. The dimension of a bounded planar poset is at most two. We show that the dimension of a planar poset having a greatest lower bound is at most three. We also construct four-dimensional planar posets, but no planar poset with dimension larger than four is known. A poset is called a tree if its Hasse diagram is a tree in the graph-theoretic sense. We show that the dimension of a tree is at most three and give a forbidden subposet characterization of two-dimensional trees.
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ورودعنوان ژورنال:
- J. Comb. Theory, Ser. B
دوره 22 شماره
صفحات -
تاریخ انتشار 1977