e/Flag (geometry)

Information
has gloss	eng: More formally, a flag ψ of an n-polytope is a set F−1, F0, ..., Fn} such that Fi ≤ Fi+1 (−1 ≤ i ≤ n − 1) and there is precisely one Fi in ψ for each i, (−1 ≤ i ≤ n). Since, however, the minimal face F−1 and the maximal face Fn must be in every flag, we often omit them from the list of faces, as a shorthand. These latter two are called improper faces.
lexicalization	eng: flag
instance of	(noun) a solid figure bounded by plane polygons or faces polyhedron

Media
media:img	Polytope Flag.PNG