  Using the density matrix theory of interaction between light and matter, and
relevant parameters of the relaxation rates for a six-level model, we have
shown theoretically the possibility of realizing Electromagnetically Induced
Transparency (EIT) and Slow Light effects in Pr(+3 ion) doped YSO crystal. In
addition, we have presented a simplified method to analyse EIT effect in such a
six level atomic system. Finally, we have demonstrated results of numerical
calculation and have compared them with experimental measurements reported
recently.
