  We propose a unified mathematical scheme, based on a classical tensor
isomorphism, for characterizing entanglement that works for pure states of
multipartite systems of any number of particles. The degree of entanglement is
indicated by a set of absolute values of the determinants for each subspace of
the multipartite systems. Unlike other schemes, our scheme provides indication
of the degrees of entanglement when the qubits are measured or lost
successively, and leads naturally to the necessary and sufficient conditions
for multipartite pure states to be separable. For systems with a large number
of particles, a rougher indication of the degree of entanglement is provided by
the set of mean values of the determinantal values for each subspace of the
multipartite systems.
