Franklin-based hospital operator Community Health Systems has announced that it has entered into a definitive agreement to purchase the assets of Memorial Health Systems in York, PA. CHS will buy the 100-bed Memorial Hospital, the Surgical Center of York and other outpatient and ancillary services. Among the deal's provisions is a promise to build a larger replacement hospital within five years of the closing date. The deal, which covers about 1,000 workers, is still subject to regulatory approvals.