摘要
Sequentially compact fts was defined by C. K. Wang in JMAA 43(1973). The derived property that each fts is a sequentially compact fts is pathology. Therefore, the definition is not a 'good extension' of sequential compactness. We shall give the definition of N-sequential compactness. In such a way, general sequential compactness is a special case of N-sequential compactness. N-sequential compactness, as well as N-compactness, has many good properties.
