# removeIsomorphicPosets -- returns a sub-list of non-isomorphic posets

## Synopsis

• Usage:
N = removeIsomorphicPosets L
• Inputs:
• L, a list, containing posets
• Outputs:
• N, a list, containing posets with non-isomorphic elements

## Description

This method returns a sublist $N$ of $L$ containing the elements of $L$, in order, where the first instance of each isomorphism class is retained.

 i1 : L = {chain 4, divisorPoset (2^3), booleanLattice 3, booleanLattice 2, product(3, i -> chain 2)}; i2 : removeIsomorphicPosets L o2 = {Relation Matrix: | 1 1 1 1 |, Relation Matrix: | 1 1 1 1 1 1 1 1 |, | 0 1 1 1 | | 0 1 0 1 0 1 0 1 | | 0 0 1 1 | | 0 0 1 1 0 0 1 1 | | 0 0 0 1 | | 0 0 0 1 0 0 0 1 | | 0 0 0 0 1 1 1 1 | | 0 0 0 0 0 1 0 1 | | 0 0 0 0 0 0 1 1 | | 0 0 0 0 0 0 0 1 | ------------------------------------------------------------------------ Relation Matrix: | 1 1 1 1 |} | 0 1 0 1 | | 0 0 1 1 | | 0 0 0 1 | o2 : List

## See also

• areIsomorphic -- determines if two posets are isomorphic
• isomorphism -- computes an isomorphism between isomorphic posets
• Posets -- a package for working with partially ordered sets

## Ways to use removeIsomorphicPosets :

• "removeIsomorphicPosets(List)"

## For the programmer

The object removeIsomorphicPosets is .