“…sage: P = Poset(( [1,2,3,4,5,6,7,8,9], [ [1,3], [1,4], [2,3], [3,6], [3,7], [4,5], [4,8], [6,9], [7,9] To compute the generalized promotion operator on this poset, using the algorithm defined in Sect. 2.1, we first need to make sure that the poset P is associated with the identity linear extension:…”