The School Committee and town officials have invited the public to a ribbon-cutting ceremony for the new and renovated buildings on the Carlisle Public School campus Saturday at 10:30 a.m. The program will include brief speeches by local and state officials, followed by a reception. School buildings will be open for informal tours until 1 p.m. With only a short list of tasks remaining to be completed this fall, the ceremony represents the culmination of a construction project that began in April 2011.