PlanarQ[g] yields True if graph g is planar, meaning it can be drawn in the plane so no two edges cross.

RankPermutation[p] gives the rank of permutation p in lexicographic order.

RankRGF[f] returns the rank of a restricted growth function (RGF) f in the lexicographic order of all RGFs.

RankSubset[l, s] gives the rank, in canonical order, of subset s of set l.

RemoveSelfLoops[g] returns the graph obtained by deleting self-loops in g.

ReverseEdges[g] flips the directions of all edges in a directed graph.

RGFs[n] lists all restricted growth functions on the first n natural numbers in lexicographic order.

TravelingSalesman[g] finds an optimal traveling salesman tour in graph g.

UnionSet[a, b, s] merges the sets containing a and b in union-find data structure s.

UnrankGrayCodeSubset[n, l] gives the n\[Null]^th subset of list l, listed in Gray code order.