StronglyConnectedComponents[g] gives the strongly connected components of directed graph g as lists of vertices.
TableauQ[t] yields True if and only if t represents a Young tableau.
Tableaux[p] constructs all tableaux having a shape given by integer partition p.
TransitiveQ[g] yields True if graph g defines a transitive relation.
TransitiveReduction[g] finds a smallest graph that has the same transitive closure as g.
TransposeTableau[t] reflects a Young tableau t along the main diagonal, creating a different tableau.
TravelingSalesmanBounds[g] gives upper and lower bounds on a minimum-cost traveling salesman tour of graph g.
TravelingSalesman[g] finds an optimal traveling salesman tour in graph g.
TreeIsomorphismQ[t_1, t_2] yields True if the trees t_1 and t_2 are isomorphic. It yields False otherwise.
TreeQ
(Combinatorica Package Symbol) TreeQ[g] yields True if graph g is a tree.