3071	 An Algorithm Using Symbolic Techniques for the Bel-Petrov Classification of Gravitational Fields	 In this note an algorithm is presented for the symbolic calculation of certain algebraic invariants of the Weyl tensor which permits the determination of the Bel-Petrov types of a gravitational field. This algorithm although more specialized than that of D Inverno and Russell-Clark requires neither the use of a special coordinate system nor the spin coefficient formalism. The algorithm has been implemented in FORMAC and is designed to complete the classification scheme proposed by Petrov in his book. An appendix contains examples illustrating the use of the algorithm. General relativity Bel-Petrov types FORMAC symbolic manipulation tensors
