GraphProduct[g_1, g_2, ...] constructs the product of graphs g_1, g_2, and so forth.

GraphSum[g_1, g_2, ...] constructs the graph resulting from joining the edge lists of graphs g_1, g_2, and so forth.

GrayCodeKSubsets[l, k] generates k-subsets of l in Gray code order.

HamiltonianPath[g] finds a Hamiltonian path in graph g if one exists. HamiltonianPath[g, All] gives all Hamiltonian paths of graph g.

HasseDiagram[g] constructs a Hasse diagram of the relation defined by directed acyclic graph g.

HeapSort[l] performs a heap sort on the items of list l.

IntervalGraph[l] constructs the interval graph defined by the list of intervals l.

InversePermutation[p] yields the multiplicative inverse of permutation p.

Inversions[p] counts the number of inversions in permutation p.

LexicographicPermutations[l] constructs all permutations of list l in lexicographic order.