The rating on Pennsylvania Higher Education Assistance Agency's $125 million education loan revenue bonds series 1995A is based on an unconditional, irrevocable bond insurance policy provided by Ambac Assurance Corp. (Ambac; 'AAA' insurer financial strength rating) that guarantees payment of scheduled principal and interest. The short-term rating reflects the likelihood of payment of purchase price based on the availability of the liquidity facility provided by Credit Suisse First Boston. The short-term rating will expire on Dec. 1, 2005, upon the mandatory tender before the expiration of the liquidity facility. Although the rating is dependent on Standard&Poor's rating of Ambac's insurer financial strength, the underlying transaction is of investment-grade quality, as illustrated by the following: Overcollateralization that opens at