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

ReadGraph[f] reads a graph represented as edge lists from file f and returns a graph object.

RealizeDegreeSequence[s] constructs a semirandom graph with degree sequence s.

ReflexiveQ[g] yields True if the adjacency matrix of g represents a reflexive binary relation.

RegularGraph[k, n] constructs a semirandom k-regular graph on n vertices, if such a graph exists.

RegularQ[g] yields True if g is a regular graph.

RemoveMultipleEdges[g] returns the graph obtained by deleting multiple edges from g.

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

RevealCycles[p] unveils the canonical hidden cycle structure of permutation p.

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