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What do we call those well-founded posets $P$ with the property that for every $x \in P$, all maximal chains in the lowerset generated by $x$ have the same length? Examples:

  • The set of all finite subsets of a (possibly infinite) set.
  • The set of all finite-dimensional vector subspaces of a (possibly infinite-dimensional) vector space.
  • The set of all finite-dimensional affine subspaces a (possibly infinite-dimensional) affine space.
  • Any set-theoretic tree.
  • Any poset that could reasonably be construed as an "abstract polytope."
goblin GONE
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1 Answers1

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I think this paper gives the definition you want, if I understand you correctly:

Definition 2.9. A poset $P$ will be called locally ranked if all its principal lower ideals are ranked.

Jair Taylor
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