Abstract
To characterize different types of quantum states is one of major inquiries in the area of quantum information. In this thesis a general scheme, combinatorial tracing, is developed, that enables the calculation of all the essential algebraic invariants for a quantum state. These invariants are considered registers or indexes that characterize an arbitrary, pure or mixed, multipartite quantum state. Specifically they provide the necessary and sufficient condition to determine whether two arbitrarily given states are equivalent up to local unitary transformations. This scheme is in practice a generalizedSchmidt decomposition.