Returns an enumerableset of ambient property information items for the requested set of types and properties.
从请求的属性集中返回单个环境属性信息项，具体情况视哪个属性是遇到的第一个属性而定。
2
This paper give the proofs of the Keal Function "a theorem that sum aggregate enumerableset is countable aggregate".
主要讨论了《实变函数论》中定理：“可数个可数集之并是可数集”的多种证明。
3
The theorem that the language set distinguished deterministic finite automaton is a recursively enumerableset was proved, and then, the recursiveness of regular language was analyzed.