General formulas of entanglement concentration are derived by using an
information-spectrum approach for the i.i.d. sequences and the general
sequences of partially entangled pure states. That is, we derive general
relations between the performance of the entanglement concentration and the
eigenvalues of the partially traced state. The achievable rates with constant
constraints and those with exponential constraints can be calculated from these
formulas.Comment: This paper revised because the previouse version has some mistake