HighlightedVertexStyle is an option to Highlight that determines how the highlighted vertices are drawn.

Hypercube[n] constructs an n-dimensional hypercube.

IdenticalQ[g, h] yields True if graphs g and h have identical edge lists, even though the associated graphics information need not be the same.

IdentityPermutation[n] gives the size-n identity permutation.

InDegree[g, n] returns the in-degree of vertex n in directed graph g. InDegree[g] returns the sequence of in-degrees of the vertices in directed graph g.

IndependentSetQ[g, i] yields True if the vertices in list i define an independent set in graph g.

Index[p] gives the index of permutation p, the sum of all subscripts j such that p[[j]] is greater than p[[j + 1]].

InduceSubgraph[g, s] constructs the subgraph of graph g induced by the list of vertices s.

InitializeUnionFind[n] initializes a union-find data structure for n elements.

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