a set with cardinality s＼s。is said to be denumerable or countably infinite. 具有基数ss。的集合，被称为是可列的或可数无穷的。
2.
An existence theorem concerning denumerable 1 - homoclinic orbits and countable families of 1 - periodic orbits was given under a generic condition ; and an intuitionistic description about those orbits was also given 证明在通有条件下，该异宿环附近存在可数无穷多条1 -同宿轨，和可数无穷多个1 -周期轨的单参数族，同时对这些周期轨和同宿轨作了直观描述。
