RandomHeap[n] constructs a random heap on n elements.

RandomKSubset[l, k] gives a random subset of set l with exactly k elements.

RandomPartition[n] constructs a random partition of integer n.

RandomPermutation[n] generates a random permutation of the first n natural numbers.

RandomTableau[p] constructs a random Young tableau of shape p.

RandomTree[n] constructs a random labeled tree on n vertices.

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

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

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.