说明：  一套多文件摘要的計算方法，給予每一個新聞群組簡短的摘要，使新聞讀者可以藉由這些簡短的摘要，大略瞭解新聞群組的內容及所要傳達的消息。
(A multi-document summary of the calculation, giving each a brief summary of the newsgroup, so that news readers can these brief summaries, general understanding of the content of newsgroups and message to convey.)