As of Version 10, most of the functionality of the Combinatorica package is built into the Wolfram System. >>

constructs a list of unordered pairs representing the edges of graph g. Each edge, directed or undirected, results in a pair in which the smaller vertex appears first.


  • ToUnorderedPairs functionality is now available in the built-in Wolfram Language function EdgeList.
  • To use ToUnorderedPairs, you first need to load the Combinatorica Package using Needs["Combinatorica`"].
  • An option called Type that takes on values All or Simple can be used, with All being the default value. Type->Simple ignores multiple edges and self-loops in g.