  Tensor calculation of suffix-contraction is carried out by a C-program.
Tensors are represented graphically, and the algorithm makes use of the
topology of graphs. Classical and quantum gravity, in the weak-field
perturbative approach, is a special interest. Examples of the leading order
calculation of some general invariants such as $R_{\mn\ls}R^{\mn\ls}$ are
given. Application to Weyl anomaly calculation is commented.
