UnitransitiveGraph returns a 20-vertex, 3-unitransitive graph, discovered by Coxeter, that is not isomorphic to a 4-cage or a 5-cage.
UnrankGrayCodeSubset[n, l] gives the n\[Null]^th subset of list l, listed in Gray code order.
UnrankKSubset[m, k, l] gives the m\[Null]^th k-subset of set l, listed in lexicographic order.
UnrankRGF[r, n] returns a restricted growth function defined on the first n natural numbers whose rank is r.
UnrankSubset[n, l] gives the n\[Null]^th subset of list l, listed in some canonical order.
UnweightedQ[g] yields True if all edge weights are 1 and False otherwise.
VertexCoverQ[g, c] yields True if the vertices in list c define a vertex cover of graph g.
V
(Combinatorica Package Symbol) V[g] gives the order or number of vertices of the graph g.
WeaklyConnectedComponents[g] gives the weakly connected components of directed graph g as lists of vertices.
PackedArrayForm[expr] prints with packed arrays in expr shown in summary form, without all their elements explicitly given.