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flagChains -- computes the maximal chains in a list of flags of a ranked poset

Usage:

C = flagChains(P, L)
Inputs:
- P, an instance of the type Poset,
- L, a list, containing rank indices
Outputs:
- C, a list, all maximal chains of $P$ containing only elements in the flags indexed by $L$

Description

The flag chains of $P$ with respect to $L$ are exactly the maximalChains of the flagPoset of $P$ with respect to $L$.

i1 : D = divisorPoset(2^2*3*5);

i2 : rankFunction D

o2 = {0, 1, 1, 2, 1, 2, 2, 3, 2, 3, 3, 4}

o2 : List

i3 : flagChains(D, {1,2,3})

o3 = {{2, 4, 12}, {2, 6, 12}, {3, 6, 12}, {2, 4, 20}, {2, 10, 20}, {5, 10,
     ------------------------------------------------------------------------
     20}, {2, 6, 30}, {3, 6, 30}, {2, 10, 30}, {5, 10, 30}, {3, 15, 30}, {5,
     ------------------------------------------------------------------------
     15, 30}}

o3 : List

See also

flagPoset -- computes the subposet of specified ranks of a ranked poset
isRanked -- determines if a poset is ranked
maximalChains -- computes all maximal chains of a poset
rankPoset -- generates a list of lists representing the ranks of a ranked poset

Ways to use flagChains:

flagChains(Poset,List)

For the programmer

The object flagChains is a method function.

The source of this document is in Posets.m2:4781:0.